Getting to know the Maz 18 Jr.
Mar 15, 2010 3:13:41 GMT -7
Guitar O' Clock, dendog55, and 3 more like this
Post by Scott on Mar 15, 2010 3:13:41 GMT -7
--------------- Getting to know the Maz 18 Jr. ---------------
This is a collection of Jr. info, and posts from various Z-Talk Members, that I found valuable to me as I was learning about my amp.
It's basically me publicly taking notes on things I found to be interesting, or just wanted handy for quick reference.
My hope, is that it may also help others too.
I do intend to keep updating this post with new info, as I bump into it. Feel free to check back now and then...
I thank the forum for the wisdom of it's members, that took the time to post up such quality info on the Jr.
It has helped me on my learning journey with arguably, one of the best amps made in The Known Universe.
Note: The Maz Jr. is probably the most versatile amp that the Doc makes...
General Information: www.drzamps.com/amp/maz18jr/
Originally designed as a "grab-and-go" studio and small club amp, the Maz 18 has made its way to some of the largest stages in the country. Don't confuse "18 Watts" with "weak and flabby". The Maz 18 will amaze you with its definition and headroom, all the way down to the low E...plenty of power for a single 12" speaker or 2x10" speakers. You'll use this amp in small clubs and never think about needing to mic it. Got a larger venue? Mic the Maz 18 and play away, because big amp tone and soul is all there. This is also a great amp for jazz guitarists, whether you're looking to replace a small blackface amp or looking for an amp with enough complexity for fusion.
The Maz 18 is an amp that every Strat or Tele player will love, but it's not only for single coil players as humbuckers are right at home with the Maz 18 too. You get great drive sounds at higher volumes or the ability to use the Lo input for cleaner humbucker sounds. With a master volume and full EQ there is plenty of room for dialing in your desired tone. The "Cut" knob may be the most useful and versatile tone shaping tool on any guitar amp. Throughout its range, it produces a large variety of sounds to satisfy players using all guitars for most every style of music. The "Cut" knob is best used after the EQ is all set; turn it up for extra edge, turn it down for a more vintage sound.
The Maz 18 has the perfect combination of front end drive and output tube distortion. It has a wonderful 3D reverb clean tone, matched with the sweetest top end response and tightest bottom end in a lower powered amp. All this has made the Maz 18 our most popular selling reverb combo to date.
The front panel features Volume, Treble, Middle, Bass, Reverb, Cut, and Master. The back panel features a 4,8, and 16 ohm speaker out. An effects loop and our EQ bypass function is also standard. The footswitchable EQ bypass gives a great lead boost which effectively makes the 18 a 2 channel amp. The 18 is powered by a pair of cathode biased EL84s and a 5AR4 rectifier.
The Maz Jr. is 'King Chameleon' in my book, ruling over Sonic Flexibility in the land, having Vox, Marshall, and Fender sounds at its disposal. Simply put, the Maz Jr. is the Swiss-Army Knife of amps. The Doc tells us on his DVD, that the Maz Jr. is his best selling amp.
When you consider all of the outstanding amps that the Dr. makes, that fact should speak volumes as to what a truly magic amp, that the Jr. is...
The Dr. Z Amps DVD: www.humbuckermusic.com/drzampsdvd.html
Note that most of the comments I have here, are not from me.
They were nuggets posted by various Z-Brothers.
Tube lessons for the Maz 18 Jr.
The Maz 18 Jr. NR Model:
V1 - JJ ECC83-S (Preamp tube)
V2 - JJ ECC83-S (Preamp tube)
V3 - Sovtek 12AX7-LPS (Phase Inverter tube)
V4 - JJ EL84 (Power tube)
V5 - JJ EL84 (Power tube)
V6 - Sovtek 5AR4 (Rectifier tube)
The Maz 18 Jr. Reverb Model:
V1=ECC83-S (Preamp tube)
V2=ECC83-S (Preamp tube)
V3=12AT7 (1/2 used as a driver before the reverb tank, 1/2 used by reverb summer.)
Reverb tank info ( Older: Accutronics 8AB3A1B ), ( Newer: P-RMOD-8AB2A1B ).
V4=12AX7 (Used in a dual Triode parallel configuration as the Reverb recovery stage.)
V5=Sovtek 12AX7-LPS (Phase Inverter tube)
V6=JJ EL84 (Power tube)
V7=JJ EL84 (Power tube)
V8=Sovtek 5AR4 (Rectifier tube)
Various plagiarized posts from the board...
Preamp tubes:
Eddie wrote: I find the reissue Tung-Sol 12AX7's to sound great in V1 of my MAZ even after comparing the tone with some more "hi-brow" tubes. I think I've tried about 15 various brands...
www.kcanostubes.com/content/tung-sol-reissue-12ax7
www.tubedepot.com/ts-12ax7.html
Russell wrote: I just put a set of the Tung-Sol reissue 12AX7's in V1 and V2 my 2003 Maz Jr. NR 2x10.
I use them in my 1x12, but this is the first time that I put them in the 2x10. These tubes sound sooooo good.
Myles latest testing on the 12AX7 Tung Sol Reissue: la-economy.blogspot.com/2012/02/tube-test-12ax7-tung-sol-reissue.html
Eddie wrote: I have had many tubes in V1 and V2 in my MAZ. Can't say I've ever owned any of the holy grail tubes like Mullards or Telefunkens, but I have had several GE, RCA, Tung Sol, etc. All just a matter of taste as they say.
It is true that your Z amp will highlight the characteristics of whatever tube you put in V1. There isn't a lot of unnecessary circuitry in a Z amp, so the tubes are it. NOS or ANOS tubes are fun to roll in your amp, but don't completely rule out some of the new production tubes.
These are still one of the best bargain newer tubes out there, imo:
www.kcanostubes.com/content/jj-ecc803s-10-12ax7-recession-sale
Also, the regular JJ 12AX7 is good if you want to make a bright amp darker, but my ears don't really like them in V1 of my MAZ Jr. anymore.
Right now, I have a Shuguang 12AX7B in V1 of my MAZ. I may be in the minority, but I love the way these cheap Chinese tubes sound in V1!
The Tung-Sol reissue tube (Myles has written a lot on this one as it has gone through various brandings) is a decent tube. Still less than $15 almost everywhere.
Basically, it's hard to go wrong with NOS, but don't overlook some of the cool new tubes out there. Most new might be junk, but there are winners for any given amp and what you are trying to accomplish tonally, imo.
Have fun tube swapping!
Eddie
Myles latest testing on the JJ803S: la-economy.blogspot.com/2012/02/tube-test-jj803s.html
benttop (Steve) wrote: Maybe I'm crazy (check that; I am crazy), but I recently spent a whole lot of time and money changing out all the tubes in my maz 18 jr. and couldn't find anything I liked better than what she was born with.
All sort of combination's in all positions, except the rectifier. 12AX7, 12AT7, 5751, LP's. GE, RCA, Sylvania, EH, Mullard, Telam, Polam, etc., etc.
I know everyone's tastes are different and it was a pretty interesting albeit expensive and time consuming exercise but in the end I have to say I still prefer the stock tubes the Doc picked out.
I found a lot differences between the various tube types and manufactures but to me the biggest change in the amp came when I tried various phase inverter tubes. Those LP's the Doc uses rock.
I was really very surprised. I actually talked to the Doc during the process do discuss my project and thoughts. He kinda of laughed and basically said; yep.....smart man.
Of course that's just me and ymmv etc, etc.....
cheycaster wrote: One word for Maz jr owners......KCA nos RFT's in the V1,V2....that is all!
Mostrummer wrote: A 5751 tube can be swapped for any of the 12AX7's (V1 or V2). This will give more clean headroom.
The cleans will stay really fat sounding. Stevie Ray was reported to do this in his Fenders.
Andy 67 wrote: I have a NOS JAN Philips 5751 in V1 in my MAZ Jr. R and a NOS RCA 7025 in V2, and I think that they complement each other very well. Tons of tone!
teleric wrote: I like running an RFT in V2. Since V2 is the extra gain stage responsible for driving the preamp (and has less of an impact on your tone than V1), I like to use a pretty "gainy" tube there - the RFTs deliver.
mazmaster wrote: Been using the high gain option from Doug's Tubes (the best!) for many years in most of my amps.
In the Maz, I use them in all three slots and feel it's the only way to go with this amp! Highly recommended.
1juicy1 wrote: After a couple weeks of playing the high gainers I'm really digging them. They really help push the Maz over the top!!
*Update: I just ordered a NOS RFT 12AX7A and it tested at 107/107.
The Hi-Gain JJ's were 105/105 on the box. Nice but a tad brittle sounding.
The RFT is supposed to be a great match for the Maz and a touch darker to tame the highs.
It's what Mike at KCA recommended along with a 5R4GYB NOS Rectifier Tube for more breakup and compression.
Myles wrote: You might want to pull those ECC83S tubes out of V1 and V2.
Look for a medium plate USA tube such as an RCA, GE, Sylvania as used in Fender black face amps in the sixties or a Mullard (if not too pricy).
V1 first. V1 and V2 if you can afford it.
trevorb wrote: I have been wanting to try a lower gain tube in V1 just for fun. Well I live close to Eurotubes and asked what options were out there. Those guys are always great and gave me a killer breakdown.
Just so happened they recommended trying a 12AT7 and I had a spare. Threw it in V1 and moved the gold pin 12AX7 from V1 to V2.
I can't believe how much better this amp sounds. It didn't loose any of the touch dynamics, and to my ears it made the amp sound worlds better with both volume and master dimed. I know I have heard some of you share about your similar experience with this same tube change and I am here to say thanks for sharing, I am so glad I listened!
Love this amp more everytime I turn it on.
Note: Using a 12AT7 will work for decreasing the gain, but the 12AT7 has a different set of plate family curves, which produce a slightly more bassy output.
Myles wrote: A 5751 is a wonderful tone generator (front end tube) but a 12AT7 is not. The gain is about the same but a 12AT7 is harsh.
Recently evaluated Preamp tubes by Steve Fryette.
12AX7A/7025 Shuguang: Well balanced tonal spectrum, low noise with moderate microphonic tendencies, easily selected out in production. Excellent for clean and overdrive sounds.
12AX7WB Sovtek: Lower gain, somewhat less bass response, and not as bright as Shuguang, but not dull sounding. Very low microphonic tendencies.
12AX7A Tung-Sol: Very good gain and low microphonics. Nice low end. Somewhat forward in the upper mids. Basically a fatter higher gain EH 12AX7. Appears to be an EH with a different getter.
12AX7 EH: Very good gain and low microphonics. Less low end than Tung-Sol and not as smooth on top. More pronounced in the upper mids.
12AX7LPS Sovtek: Similar to the EH but generally a little less of everything. Nice balance and a good alternative to the Shuguang if you like less top and a little more mid.
12AX7/ECC83 JJ: Works well in Valvulator 1, which was surprising, since it did not fare as well in prior testing. Apparently the hum and microphonic issues have been addressed. A little darker sounding than the WB. When used in the amplifier V1 stage, this tube performs similarly to the WB, but the mids are more pronounced, the top end is dullish and overall somewhat harsh sounding for high gain settings.
chetz wrote: The 12AX7 is so widely used in guitar amps, I thought I would throw this up to help explain I the different variants.
I am a big proponent of NOS tubes but they are risky buys at times and you better be able to test them.
They have made a significant audible improvement in EVERY amp I have put them in.
A Tube marked ECC83 is exactly the same tube as a 12AX7. It is simply the way the were marked in Europe.
A 7025 marked tube is a low noise industrial version of the 12AX7.
A 5751 is a U.S. military spec 12AX7, and has about 30 percent less gain typically. You can beat the hell out of them though.
A 6681 is another industrial tube, and a step up from a standard 12AX7.
Tubes marked ECC803S, E83CC, E803CC are premium versions of the ECC83. Telefunken, Siemans and occasionally Mullards can be seen with such markings.
S stands for 'Special' or screened for low noise.
You will also hear about Longplates ( 17mm ) and Shortplates ( 14mm ). The longplates are considered more desirable and are much rarer and more expensive.
Between Smoothplates and Ladderplates, Smoothplates are generally considered to have more definition and detail.
I hope this helps some of you, it was confusing as hell to me at first.
Peace,
Jeff
Myles site on preamp tubes: www.guitaramplifierblueprinting.com/12ax7.html
Also...
Preamp Tubes - The most critical, least expensive, most overlooked tubes in your amp: la-economy.blogspot.com/2010/09/most-critical-least-expensive-most.html
Myles knows his stuff!!
A Microphonic Preamp Tube
Reverb tubes:
You can change the character of the verb a bit with tube swaps.
Eddie posted a downright beautiful clip in the audio section of his MAZ with a 5751 tube in V3 and a 12AX7 in V4: ztalk.proboards.com/index.cgi?board=soundfiles&action=display&thread=28465
Eddie wrote: I tried 12AU/Y/T all in the driver slot of my MAZ. Each does change the reverb a bit. Really just seemed to make it weaker in that you'd have to run the control higher to get the same level.
The tone may have changed a little, but not a whole lot.
It WILL change the feel of the front end of the amp - even with the reverb off. It's subtle, but running a hot 12AX7 in 3 makes a difference.
In the end, I went back to a 12AT7 in V3. I like it best - both before and after I had changed the tank from the old accutronics to the newer MOD tank.
Surf on, bro!
Eddie
Tip: To tame an over active Reverb Tub, try a 5751 in V4 ( Reverb recovery stage ).
The Phase Inverter tube:
The Phase Inverter tube, is located closest to the Power tubes.
Use a tube with balanced triodes for the PI.
Dr Z recomends a balanced Sovtek 12AX7-LPS (long plate spiral filliment).
Mike at KCA tubes can help you out with that: www.kcanostubes.com/content/sovtek-12ax7-lps
The Doc designed the Jr. to use the 12AX7 LPS as the Phase Inverter.
Tip from the Doc is to return the Jr. to it's original tone, replace the PI with another LPS.
For a little more clean headroom, try a balanced NOS 12BH7, or 5751. That will also smooth things out some.
Here's some General Guidelines on tube gain. The tubes being produced today have very inconsistent gain, from tube to tube.
The only real way to know for sure, is have them tested. It really is a crapshoot...
12AX7 = 100% or the standard 12AX7 spec. (1.2 mA at 250 volts with a -2 volt bias.) That reference spec also applies to 12AX7 / ECC83 / 7025 tubes.
12AT7 = Has 70% of the gain of a 12AX7.
12AY7 = Has 44% of the gain of a 12AX7.
12AU7 = Has 17% of the gain of a 12AX7.
I don't know the number for 12BH7 but it is very low.
My fave is a NOS 12AY7. A 12AY7 is not going to be a bright or snappy tube. It's all compromise.
It's hard to say exactly how much extra clean headroom you'll get from the 12BH7 PI swap; it depends on other factors like your guitar's pickups, your touch, etc. but it's a decent amount.
** Note: Changing your stock phase inverter tube over to a NOS 12AY7 will give you more clean headroom, but the amps overall volume will be less than before.
bluzman wrote: To me the LPS in the phase inverter gets too bright with my Teles.
I've tried the 12AX7-LPS in V3 and it sounds very good, but for my tastes, I still prefer high gain JJ-ECC83S in all three slots. (V1, V2, and V3 on NR Model.)
I really like the GT12AX7M in V1 and in the PI spot as well.
Scott wrote: New rule for me - I like the gain of an actual 12AX7 in the PI position. Running a tube with too low of a gain here, can change how your Cut Control will need to be set, and the level of volume required to let the amp's sound open up, probably first requiring both Volume and Master settings to be past 12:00. A 5751 PI does not have enough gain for me, and caused me to run my Cut Control from a normal 9:00 position, to a new 3:00 position to sound close to the same.
The JJ ECC803S 12AX7 is a long-plate tube, and I read somewhere they work nicely as PI tubes. Try it and see what you think.
JJ ECC803S ( 12AX7 ): thetubestore.com/teslaecc803s.html
"Description: The latest preamp tube from JJ is a very long plate classic European style tube with thick mids and a little more high end than the ECC83S. Great in V1 or in all positions in vintage amps. Also available matched or with balanced triodes for phase inverter use."
JJ ECC803S ( 12AX7 ) Gold Pin: tubedepot.com/jj-ecc803g.html
"Description: The Gold Pin JJ ECC803S is also designed to be a premium version of the long plate JJ ECC83S. The Gold Pin tubes are a bit smoother in the high end and a bit richer in harmonic content so they are an excellent V1 tube in guitar amps. (Not recommended for combo amps) They are also available with matched triodes and with current balanced triodes."
Myles wrote: Gold pins will stop the corrosion on the surface of the pins on tubes sitting on shelves in storage. Once the pins are in contact with a socket that is not gold plated there will still be corrosion on the socket. Two dis-similar metals will generally corrode when they contact each other. Gold pins - cost virtually nothing to produce as the process is so simple and the plating is so thin - NO benefit with greater cost. One of the biggest scams in the tube world.
A 12AY7 in the phase inverter spot will give lots of clean headroom, as will a 5751 in the PI slot.
You will get more clean headroom with the 12AY7, than the 5751, but both give more clean headroom than the 12AX7.
For max clean headroom, also make sure your output tubes are fresh...
I do not select my phase inverters based on Gain, and Transconductance is also something of a false indicator for me. For a phase inverter, I look at plate current and plate resistance. If the plate resistance is within spec (62.5K at 250 plate and 2 volt bias) then then tube has a good chance of being excellent. If the plate current is too low or too high it means that the tube has some sort of defect and the plate resistance is not correct or there are other problems. Since the phase inverter drives the output tubes I look for current rather than TC or gain.
I also look for rise time with a curve tracer. Depending on the application and style of the player I may desire a faster (tighter) or slower (looser) response. Chad Weaver (Brad Paisley) has a drawer of tubes with different characteristics that he swaps in and out of amps depending on how Brad feels in a given venue.
Look at the old Groove Tubes 12AX7M reissue, the later production runs had the highest TC of any 12AX7 ever made. It also had the highest plate current. But... the plate resistance was half of design spec, or less, in most tubes. This gives very high TC, high plate current (tube runs very hot) but VERY low true gain in circuit and there is more crosstalk between the A and B sides of the tube.
A classy and articulate description of this would be: Crappy tube.
A 12AT7 has about the same actual gain as a 5751 but has about ten times the plate current at 10mA vs 1.2mA of the 5751. It also has a very fast rise time. In Fender tolex era amps it was picked for clean headroom and good drive current to push a quad of 6L6 tubes.
A simple blackface or silverface trick to make a Fender more aggressive is to swap the stock 12AT7 with a 12AX7. Plug and play... no adjustment needed.
Telefunken 12AX7's are not a good choice at any cost for a phase inverter from my point of view. Most have very low plate current, very low transconductance. But, with plate resistance of 80-100k which was common, their true gain in circuit was over 100 in many cases. They are the highest gain 12AX7 / ECC83 tubes made. Because of the high gain they were very responsive but the high gain made them more prone to physical microphonics.
Whether you run a 12AX7, a 5751, a 12AT7, etc..., is really a matter of design, and personal taste with countless options.
I generally prefer long plate tubes in the PI slot (my personal general taste much of the time but not all the time).
This can be a Sovtek 12AX7LPS, JJ 803S etc.
It need not be expensive but have the vendor assure it does not rattle at all and assure that the plate current is at least 1.1mA (1.2mA is spec).
Most today are 0.8 - 1.0mA and we don't want a weak phase inverter straining when it tries to properly drive the output tubes.
In many amps it is not as much the output tubes you hear distorting, it is the phase inverter taking a dive because it is weak.
If you want to be sure things will work properly and for many years you can go the NOS route on the PI.
If you decide to run a NOS 12AX7, you can't go wrong with RCA, GE, Brimar, Mullard as just a few examples.
One more side note on PI replacement... 6L6s are hard to drive. So are 6550s and KT88s. EL34s are not too bad but amps with master volume controls can tax the phase inverter on EL34 amps depending on setting and depending on the master volume being pre or post an area of the cicruit.
EL84 tubes are very easy to drive. In the case of the MAZ Jr. the PI will last many output tube changes.
I have seen no change in specs on PIs in MAZ, Mazerati, or other Dr. Z EL84 based amps over a dozen output tube changes, unless the PI had some sort of quality defect issue built into the tube originally.
A pdf file about phase inverters containing quality info:
The most important tube in your amp? The Phase inverter! www.guitaramplifierblueprinting.com/files/Phaseinverter.pdf
"Going from a 12AX7 to a 12AT7 in the PI (phase inverter) will yield a change in output tube distortion, touch, and output dynamics in most amps.
Is this because the gain is lower in the 12AT7? 10% yes perhaps.
The lower gain is a factor but the larger factors are:
• We have almost 10 times the current available to drive the output tubes before the phase inverter starts to break down.
• We have a transconductance of 5500 vs 1600 of the 12AX7. Keeping this simple, it means it takes a lot less input signal for a given output signal."
The Power Tubes:
The Maz 18 Jr. is cathode biased, so buy a matched pair and there will be no need to have the amp re-biased.
Carry a matched set. If you replace a single tube it will not be matched, even if it came from a set that was matched to the original set, as these cathode biased EL84s wear very fast.
Question: How many hours do EL84 Power Tubes last at gig volume levels, in a Cathode-Biased amp?
Myles wrote: This varies on amp and personal taste. I know folks that play for a year or more on EL84 tubes in cathode biased amps.
I also have folks that change their output tubes after ten shows, about 30 hours.
I notice a difference. Most everybody around when this is done notices a difference.
As more hours are put on a tube the reliability will go down.
If you are playing a 20,000 seat venue the reliability factor might be a consideration if you favor a particular amp in your setup even if you have many other amps on stage.
In the end it is personal taste.
A handy 'EL84 Tube Type Review' link, courtesy of TheTubeStore: thetubestore.com/el84review.html
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A lot of us really like JJ's for EL84 tubes. www.eurotubes.com/
www.tubedepot.com/jj-el84.html
rickc007 wrote: I ordered some JJs and some TAD's. First put the JJs in, and got a bit more power.
Tried the TADs, and first thought was "more balanced". JJs were a bit more in the bass and mids.
Then I got to missing the extra low end oomph. Put the JJs back in, and I likes them.
Liked TADs in another amp I had, but JJs do it for me in the Maz.
shouldb (Pete) wrote: Me too - on my third set of JJs and love them.
beanbag wrote: JJs are my "goto" El84. In my experience, they are the most consistent in performance and reliability of any new production.
Andy 67 wrote: +1 on Eurotubes and JJs!! Tons of tone!
"z" Steve wrote: For about 5 years I've used Bob at Eurotubes to by my JJ EL 84's for my amps requiring those tubes. I have also used Mike at KCA for trying the TAD EL84's just for a change. Both brands have worked great and I have not had a failure or issue with either. Both Bob & Mike will set you up with tubes to your liking as far as breakup - early or late.
On ( Aug 26, 2011 ) - DRZ wrote: OK guy's here's the skinny on JJ tubes: Over that last 6 months I have seen a noticeable decrease in quality. I currently have over a 25% rejection rate on JJ 12AX7's, and the same can be said for the JJ EL 84's.
It is a shame because JJ's were the most rugged tubes on the market, but they have slipped, boy have they slipped.
I have reported this to my US importer and just received some lip service and a bump in cost of 12AX7's, probably due to my large number of returns.
And speaking of returns were do you think my rejects go...
So what is amp builder to do, well I re-evaluated Sovtek EL-84-EH's and like the results.
Tighter builds with less filament rattles, and much less harsh ( upper Mid Response ) then the available JJ EL-84.
In all the new facelifted MAZ line ( that is ones with the new front panel ), we are using EL 84-EH's with great results.
I will be using more EL 84 EH's , so look into them when it's time to re-tube.
As for the JJ 12AX7 I still like them in the first position of most amps but have switched to Chinese 12AX7 HG+ in tone stack driver pos #2.
DR.Z
dobro1 wrote: This is a topic I can relate too for sure. I went through 3 sets of JJ's and they all went bad within a month one set 2 days. I was thinking there must be a problem with the amp. I have used JJ's for a long time and they always sounded great and never had quality issues like that. I bought a set set of EH and they sound great and been using them for 6 months with no problem the only thing I noticed is it seemed like I lost the slightest bit of volume with the EH but the quality of sound is excellent.
abandoned wrote: I asked Brent at Dr. Z and he said that they prefer EH cuz JJ's "have something harsh about them", that you can't really dial out.
He said using JJ's sparingly is ok but using a lot of them in one amp is not a good idea... due to the harshness.
BritInvasion wrote: I gave up on JJ's after red-plating 2 sets in a row. I am using TADs now and really like 'em.
I've heard EH are generally pretty good, and like others say here a little darker than JJ. But I don't have first-hand experience with EH.
mazmaster wrote: I have set of older Groove Tube JJ EL84s, and a brand new set of perfectly matched JJ EL84s from Ruby Tubes via Doug's Tubes, and a brand new set of TADs.
All of which I tested yesterday.
I found the older JJs to be my favorites. They were warmer, fuller and less harsh then the new JJs and the TADs.
The new JJs were surprisingly bright and a little harsh. The TADs sounded a little metallic and tanky in the mids to me with OD pedals.
I got a chance to compare my older JJ-EL84s, to a brand new pair of JJ-EL84s, and a brand new pair of EH-EL84s.
I preferred the older JJs to the EH and new JJs.
The new JJs were VERY bright, and the EH mids didn't blend well with the mids of my main OD pedals.
I'm sticking with the older JJs till they die or get dull. They have a fantastic blend of smooth mids and highs and no harshness.
I don't know what's going on with JJ, but they really do seem to be going downhill and with no good alternative that I've found yet.
flapp wrote: I recently returned a Set of JJ 84's to a dealer and threw another set in the trash. The last two quad sets I have ordered have had problems. Maybe it is bad luck. Maybe I keep getting sent the same tubes, but I was talking to Don, very anxiousely about my AMP problems...in the end it was power tubes. JJ84's.
One set lasted about 2 months and then started cutting in and out. The next set were noisy and completely changed the feel of my 38.
So I will try the Electro-Harmonix 84's recommended by the Doc.
Not all my JJ's have been bad of course... Just recently it seems.
Myles wrote: JJ used to be the tube to use, the good old tube that lasted a long time and sounded very vintage.
Over at the shop the JJ 803S and all of their output tubes have shown a decline in specs, wider spread in tolerances and have been more physically microphonic in the past three to six months.
The best tubes today seem to come from Tom McNeil at Magic Parts ( Ruby Tubes ), He has some very nice 12AX7s, and EL84s. magicparts.com/main.htm
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Here is the Electro-Harmonix version of the EL84 power tube, that the Doc is going to in 2011: thetubestore.com/ehxel84.html
evilsmooth wrote: Compared to the old JJ, the EH sound darker and seem to have less power as if my amp goes from a great 18w to a 10-12w...
I won't by another matched EH anymore. I'm looking on TAD...
number9 wrote: I swapped out the old JJ EL84's with new EH EL84's today. The EH's are slightly scooped but more pronounced in the low-mid frequency, they don't jump out at you like the JJ's. I could run the CUT knob higher with the EH's, but some might miss the high-mid frequency articulation of the old JJ's. The EH's have a great lively feel, some moderate spongy compression, and they sit back in the speaker nicely besides some low-mid frequency droning. For those of you using boost pedals ( Beano Boost, AC Booster, Tim etc. ), or drive/distortion pedals ( TS-9, BB Preamp, Hellbender etc. ), the EH EL84's might be a great pick. I actually preferred the way the TS-9 Silver sounded with the EH's, it balanced things out and sounded as good as ever.
Note: These tubes have a slightly larger diameter than other EL84 tubes so they can not be installed into some Marshall DSL201 or DSL401 amplifiers, some reissue Vox AC15 amps, and Bad Cat amps.
Note: One Maz Sr. member, abandoned wrote: Well I recently had my Maz38 Sr. retubed with ElectroHarmonix EL84's hoping they'd be an improvement over the JJ's I had in previously. And I was met with unexpected results. The moment I received my EH's and put them in and turned on the change in tone was very apparent...
The EH's did not have near as much treble and presence as the former JJ's. The tone was also more woody.
I used to run my Cut & Treble very low - like around 10 o'clock. But since the EH's went in I've literally been running those controls at 11-12 o'clock. Which is a pretty big difference - especially on the Cut control cuz its so bright.
I personally like the tone of the JJ's better - all the brightness and liveliness and bounce of the JJ's was so much better in my opinion. My tone was so much duller after the JJ's got pulled out for EH's.
Now here's the tricky part though - the JJ's are so unreliable. I went through 2 quartets of JJ EL84's in just a few months.
They had issues like major white noise, crackling and hissing after just a couple months of use.
So cuz of their lack of reliability I've had to go with a different brand name. I chose EH cuz they are what come stock with Z's now but I'm not fond of their tone.
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I'm also still a fan of the TAD EL84's. These tubes along with the Sovtek 12AX7-LPS in PI are just ear candy.
www.kcanostubes.com/content/tad-el846bq5-str-singles-pairs-quartets
"Smoother and less bright than the JJ's. Good if you need to tame that Dr Z or other amp."
BritInvasion wrote: I'm using TAD EL84's in my Maz 18 Jr and I agree , they have a great warm sound. Took the harshness out of the highs I was getting.
teleric wrote: I recently put a new set of TAD EL84s in my Maz 18 - nice sounding tubes - the sparkle is back in my Maz.
twoscoobysnacks wrote: +1 on the TADs. I believe they definitely tamed the brightness a bit on my Maz Jr.
bluzman wrote: The TADs are now using a thicker glass. I've bought quite a few of the EL84, 7025 and 6V6. I'm going to put a quad in my Remedy as that is getting noisy.
I think it comes down to QC on the testing and at least the TADs have been consistent from my experience.
cheycaster wrote: Man I am loving the NOS RFT's i got from Mike at KCA tubes. I just stuck in one of the pair of TAD'e #6 I got from him too and I love them! They are nice and full and smoother sounding to me and my CS Clapton with CS Fat 50's really shine now as these tubes kind of rolled off some of the higher /harsher frequencies from it. I am trying them out in my 01 Maz Jr. Reverb combo with a well broken it V30. they are #6 on the GT scale if that means anything. But just the RFT made the difference for me to take notice and think.."WOW" me likey!
Myles wrote: The TAD stuff is made in the Shuguang factory in China. They are quite nice. TAD's have a 42% shorter life than a spec JJ in stress testing before 20% drop in plate current output is noted. The TAD is a Chinese built tube and shorter life in some output tubes is to be expected. Looking at how long some folks run their EL84s this might not be a factor at all for a lot of people as many are running quite a bit lower than 20% down due to tube replacement that is put off. Bottom line ... If you like how they sound that is what is most important. On shorter life ... most folks keep the same output tubes in use long after their tone and response has degraded.
Sort of like watching a child growing up, you don't notice a change unless you don't see them for years.
In amps you don't hear how much things degraded until you plug in a fresh set.
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nicholas wrote: The Mullard El84's (New Production) just sit right with me: store.tubedepot.com/mu-el84.html
They still have all the chime of a JJ or similar but when pushed they are real creamy and smooth.
They do seem to have less headroom in general, so if loud clean is your thing you might not like them.
I play mostly blues and blues based rock so they fit my needs perfectly.
In other amps I have run them for at least 20 hours a week and replaced every 3 or four months as preventive maint, only. No failures yet.
strictlydrz wrote: I've had a pair in my Maz Jr for several months, from Tube Depot - I like them too. Seem a little less smooth than the JJ's I've had in the past, which is fine.
crxsh wrote: Just picked up a set of these Mullards and finally got to do some swapping today, so I thought I'd put my 2 cents in here:
The JJ's seems to have more gain to my ears, but strangely enough, more clean headroom at the same time. With my Maz, I could have the volume knob around 1:00 with the MV around noon and still keep it pretty clean. Conversely, the Mullards start to break up a little right around 10:30 on the volume knob... and by 12:00 you're easily into some audible gain territory.
When cranked, it seems to me that the Mullards don't have quite the same aggression as the JJ's. Where the Mullards are smoother and a bit "saggier" in texture, the JJ's have a more crisp bite to my ear. More compression and, I do believe, a bit more gain.
Both are nice and choosing between the two sort of depends on what sound/texture you want... but those are my findings.
nicholas wrote: I'm still stickn' to the Mullards in my MAZ R. I recently tried some JJ's and TAD's.... The Mullards just do it for me. Smoother treble and less aggressive, I like it.
I find I can run the cut much higher ( almost maxed ) and still keep it smooth and thick.
I'm still using the same old NOS RCA 5V4 Rectifier also.
I find I have plenty of headroom... master full... volume at 10:30 with a LP. Thats clean to me.
byrdland wrote: As far as output tubes, I have tried JJ's, TAD's, Brimar and Mullard re-issue. The TAD's and Mullards seem warmer, less bright than the others. I seem to prefer the Mullards.
number9 wrote: Just wanted to give you guys a heads up/FYI that the new production Mullard EL84's and 12AX7's sound really good. So far I've tried old/new JJ's, new EH, and new Mullard's in the power section. They've all been pretty good, no bad experiences, but the Mullard EL84's have a silky smooth ear pleasing sound, plenty of nice harmonic detail, and are DEAD quiet, great for folks like me rockin' the reverb model. The Mullard 12AX7 sounds great too, a little less gain but more detail and less harshness compared to the JJ that was in V1. I could have simply lucked out with this pair, but so far so good, really good! Hopefully they keep it up!
My current tube arrangement for anyone that's curious:
V1 Mullard 12AX7
V2 JJ 12AX7
V3 JJ ECC81
V4 Sovtek 12AX7WB
V5 Sovtek 12AX7LPS
V6/V7 Mullard EL84's
-number9
zorange (Zach) wrote: I'm using Mullards and have been for a while now!
I love love love love their sound! With my MV around 2 or 3, these things sound so good!
I love their overdrive sound as well. Not brittle or spikey in any way.
Only one bad tube from Mullard when ordering from thetubedepot. And that's out of 4 tube changes now.
peterd79 wrote: I just dropped in two Mullard EL84s and i've got to tell you that I'm soooo in love with my Maz Jr. It's nuts.
I just love the Mullards in this amp...
The stock JJs are great but for me the Mullards really set this up for a blues box that is just incredible.
Myles wrote: These have nothing to do with any NOS Mullard design, and are little more than a stout and dark Sovtek EL84.
They are a very reliable tube and that is a very nice factor. They have a longer service life than the TAD offering in stress testing. They are a bit dark for my taste.
Some folks may prefer them being a bit darker, as many EL84 amps tend to be voiced quite bright.
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Eddie wrote: With the quality of JJ tubes slipping lately and some having trouble with EHX, is it maybe time to go back to Sovtek EL84 tubes?
www.tubedepot.com/so-el84.html
I know ten years ago, nobody liked them for tone, but they were at least durable. Maybe they are a little better these days?
thoughts?
Eddie
headshrinker (Marc) wrote: Looks like I'm in the minority, but I love the Sovtek EL84s.
Knock on wood, I have never had one go down on me and as a rule in bright amps they warm up things and go into distortion quicker than than JJs, without that upper mid peak.
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Tip: Don't buy the Genalex Gold Lion RI EL84's: ztalk.proboards.com/index.cgi?board=tubes&action=display&thread=21616
They seem to have a high failure rate, and rather expensive: thetubestore.com/goldlionel84.html
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New JJ EL844 tubes w/ 30% less output for Maz: www.amazon.com/JJ-EL-844-Vacuum-Tube-Matched/dp/B004DF0EPY/ref=sr_1_1?ie=UTF8&s=musical-instruments&qid=1298355807&sr=1-1
The JJ EL844's Data Sheet: www.tube-town.net/info/datenblaetter/tubes/jj/jjel844-tt.pdf
Dr. Z speaking on how the torture test went with the JJ EL844's, using the Maz Jr: ztalk.proboards.com/index.cgi?action=display&board=maz18&thread=37862&page=1
DRZ wrote: OK I did more testing and the results are:
The EL-844 held up to the torture testing quite well.
What they will do long term in the real world of gigging, only time will tell.
They sound very nice, less top end cut and more low end fullness.
Which some might like.
But the lower wattage isn't very noticeable, you almost have to ask yourself is that really lower volume.
Again they didn't do as well in the Ghia, I don't know why maybe the higher bias resistor, conjunctive filter, and much lower plate voltage, all added up to loss in good tone IMHO.
The difference in output power is less then one click on the Air-Brake.
So not sure if that justifies a purchase, but for 30.00 a pair they might be a nice subtle change of pace.
DR.Z
1juicy1 wrote: Thanks Doc!! That is what I found, one click on my brake lite and the tone is a subtle difference. But it is different.
Especially nice for us higher preamp volume players!! Combined with the high gain JJ12AX7A's its a big difference!
greenblues58 wrote: I ordered a matched pair for my nephews Laney LC15 and thought I would pop them in my Maz 18 to try them before fitting them to the Laney.
Bit of a surprise as they sound very fizzy when ran with the master high,which I tend to do,and lacking in bass and treble overall and slight difference in volume.
Tried with different guitars all sounded as above.
Stuck them in the Laney in place of its stock issue JJ EL84's, and wow it sings like a bird with my nephews Les Paul studio pro plus which has burstbuckers.
It did not sound bad with the EL 84's, but they were definitely on their way out.
Mark N wrote: I have a set in my Maz Jr... I like em... No real difference in tone...
Might be a slight volume difference overall. No complaints here!
I have only gigged the amp a couple times since getting them and I was more than pleased with the tone!
I have tons of bass, treble, or whatever I need.
1juicy1 wrote: I Love 'em in my Maz! On my second set in fact!
joebou wrote: I also really like these tubes, but I have also changed my recto to a 5y3, I was in search of the proper tone vs volume situation, and I seem to have found it with this setup. I also put a 5751 in v1. All of these small changes added up to a huge difference in overall tone, and reduced my stage volume dramatically. I'm lovin it.
wubberdubber wrote: I put a quad of these in my MAZ 38 and did a few gigs with 'em.
I didn't notice much difference except in the low-end response... Seemed a little looser than the JJ EL84's that had been in there.
Myles wrote: I truly feel it is just a substandard EL84 from their regular product line.
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Question: Will a 7189 Power Tube work in a Jr?
www.kcanostubes.com/search/node/7189
YES, a 7189 will work fine as a replacement for an EL84. This is the "industrial" version of the ( EL84 / 6BQ5 ).
The difference with pinouts between the 7189A and the 7189 are all the same except that the 7189A has:
Pin 1 is connected internally to Pin 2 ( Grid )
Pin 6 is connected internally to Pin 9 ( Screen )
A 7189A would usually work in an EL84 amp too, but a 7189 might not work in an amp designed for 7189A.
There is one way a 7189A wouldn't work in an EL84 amp. If somebody was using pins 1 or 6 as a solder point for a resistor.
Some amps will use pins 1 or 6 to get more point to point going. (Fender comes to mind)
Will a 7189A work in a Jr? Unknown... The Tube Socket would have to be examined to verify that pins 1 and 6 were not in use.
Also, you can't use an EL84 in place of a 7189, in an amp designed for 7189's.
7189's have 400V on the screen and plate, and the 7189A has even more at 440.
The EL84/6BQ5 can only handle 300 volts, so they couldn't happily exist in an amp looking to send them an extra 100 volts or more.
It's putting EL84's into an amp designed for 7189's that you may get into difficulty because of the higher voltages.
A 7189 will run down to the same voltages as an EL84, but an EL84 won't run up to the same voltages possible as when using a 7189.
Telemanic wrote: One of my personal favorite tubes and a collecting passion, is the 7189A. In certain circuits it seems to defy the fact that it is basically a heavy duty EL84!
It EASILY handles it's rated 440v plate voltage (compared to 250v for EL84). The amps I have that use them usually are running about 465 + plate volts and they don't blink. Now here's the deal with them, Ive studied these suckers a fair bit and made some interesting discoveries: #1, In (almost) every case you can sub them for an EL84 requirement with great results. The exception is a Mesa .50 cal amp i believe and perhaps a rare few others that use pin #1 for some internal tie off's. In NOS EL84's, 7189, & 7189A, pin 1 and 2 are internally connected and cannot be used in those amps. Whereas new production EL84's do not have this connection. MOST amps don't care as they don't use pin 1 anyway, and can use EL84, 7189, & 7189A.
The most obscure fact about 7189A exclusively is that they ALSO internally tie pins 6 & 9. In almost all EL84 amps it is a moot point as pin 6 is not used in the circuit. Hence, 7189A will work anywhere an nos EL84 will, ... but not necessarily in reverse. In some old amps that run an ultra linear output tranny they actually use pin 6 for the screen grid, and thus a down grade to EL84 will not work, irrespective of the voltage req. SO to sum up, a 7189 or better a 7189A will give you a bit more headroom, beef, and big bottle sound than the EL84.
Two last caveats, ... European NOS 7189A's (Mullard etc.) do not tie pins 6 and 9! say what? I Have no idea why, but they decided not to follow the GE pin out schematic. I have a Quad of beautiful Mullard 7189A's that don't work in my stock wired Magnatone amp! And lastly the 7189/7189A is becoming nearly extinct ... which makes everything i just posted nearly moot! LOL! So Happy hunting, if you can find some they are a cool alternative to EL84, even if temporary. - Peace
** Note: We have yet to get a single report of a 7189A tube successfully being used in a Maz Jr.
This info was kept by me due to it's quality, and if proven that 7189A's do work fine in a Jr, it's future value.
Scott wrote: Myles,
I was looking around your site, and was wondering if you had ever posed any words of wisdom, or your general impression, of NOS 7189 tubes. I have a set of NOS RCA 7189's and was wondering what you might think of them.
Myles wrote: These are terrific.
Think of an EL84 that can tolerate much higher voltages.
The plate current output is the same as an EL84 @ 48mA at standard book voltages but the design voltage max on the plate is 400. On the grid 300.
Plate Dissipation ............... 12 W
Grid No. 2 Dissipation .......... 4 W ( 16 watts total )
The EL84 / 6BQ5
Plate Voltage .................. 300 V
Grid No. 2 Voltage ............ 300 V
Plate Dissipation .............. 12 W
Grid No. 2 Dissipation ......... 2 W ( 14 watts total )
Bottom line... they will run stronger. You also have more output by at least two watts (in pentode mode the screen and plate wattage is combined)
Most amps run EL84 tubes beyond spec at over 300 plate volts in most cases.
The 7189 handles these voltages with ease and the tube is more reliable as it is generally running well within its intended design range.
They also sound outstanding.
** FYI - There is a current production 7189 tube being made...
hitoverdrive wrote: I like demoing tubes just to see how they do in my amps circuit. I like to find out for my self how they sound and feel. I also like asking peeps opinion on them as well so I can save money through others experience paying attention to what amps they're using these tubes in and other variables. I pretty much know what I like in my 2 EL84 amps now. Every once in awhile I will try something different. I read the description given about the tube at the site selling them and then laugh. After that I'll pick up a pair and try them out if I'm interested.
Right now I'm demoing the 'Preferred Series 7189 ( Premium EL84 )': thetubestore.com/preferred7189.html
They are almost as much as my RFT's. So far they are holding up in the Monza. They have a bit of hair on them right now but they are not stiff. Lows are big, mids present and the highs not strident. I'm liking them so far. Good dynamics when rolling off guitar volume. The hair comes in when wide open and goes away when rolled off a little. My RFT's are smooth throughout. I'm running a Miniwatt 12AX7 in V1 and JP 12AX7WA in the PI. Anyways these are suppose to be rugged and long lasting.
rhoydotp wrote: Sending some "K" to texan2step & ajb20002 for the heads-up on this tube ... though I have to put more mileage on it, it sounds great so far. When I got the amp this year, I didn't bother replacing the GTEL84 that were in there. I think prefer the sound of this to the GT.
texan2step wrote: Glad to hear that you like them! I think these get a great chime but with a slightly warmer sound which I prefer. I hope you'll continue to enjoy them. I'm slowly replacing all of my EL84's in all of my amps for the preferred series. Happy playing!
Myles wrote: When comparing them to the common Sovtek EL84M heavy duty EL84, we may find little difference to justify the high cost.
Sonically, I do not like these in guitar amps as I find them not as articulate as some other EL84 types or NOS 7189 types but that is just my own personal taste and preference. Others may have the opposite feeling.
In a hi-fi amp they may be a good option as most hi-fi amps are not cathode biased. In a cathode biased guitar amp I don't think the duty cycle would be extended long enough to justify the high cost.
$25 for a current production (or out of production old stockpiled Russian surplus tube) is a bit out of line for my taste. We are not talking Mullard, Telefunken or classic NOS tube here.
Those 5,000 hour figures they state on the website? Probably obtained using standard plate spec voltages in a grid biased configuration. Guitar amps do not work in that manner.
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Myles wrote: Here is a bit of a wrap up on reliability testing of a few EL84 types:
Genalex - Gold Lion N709 / EL84 - Tube Depot has some real ones.
They comment: Originally made by Genalex in England, the famed N709 is once again available. Made in Russia to exacting standards, the new Genalex – Gold Lion is a true echo of the past. These Russian re-issue tubes do a great job of reproducing some of the magic of the original. Due to excessive current demands found in cathode biased amps (such as Vox AC30 and others), we do not recommend these tubes for use in these types of amps.
The above paragraph sort of says it in a nutshell. Not very long lived.
Short Life:
Electro-Harmonix EL84 EH
EI EL84
Medium life:
TAD EL84
Mullard EL84 / 6BQ5 New Production (a few internal changes possibly)
Long Life:
JJ EL84 / 6BQ5
Sovtek EL84
Sovtek EL84M (very dark tone, darkest of the EL84 types)
A Microphonic Power Tube
More Maz Jr. info continued on 'Reply #4' in this thread.
Any other words of wisdom on the Jr., please post them up!
This is a collection of Jr. info, and posts from various Z-Talk Members, that I found valuable to me as I was learning about my amp.
It's basically me publicly taking notes on things I found to be interesting, or just wanted handy for quick reference.
My hope, is that it may also help others too.
I do intend to keep updating this post with new info, as I bump into it. Feel free to check back now and then...
I thank the forum for the wisdom of it's members, that took the time to post up such quality info on the Jr.
It has helped me on my learning journey with arguably, one of the best amps made in The Known Universe.
Note: The Maz Jr. is probably the most versatile amp that the Doc makes...
General Information: www.drzamps.com/amp/maz18jr/
Originally designed as a "grab-and-go" studio and small club amp, the Maz 18 has made its way to some of the largest stages in the country. Don't confuse "18 Watts" with "weak and flabby". The Maz 18 will amaze you with its definition and headroom, all the way down to the low E...plenty of power for a single 12" speaker or 2x10" speakers. You'll use this amp in small clubs and never think about needing to mic it. Got a larger venue? Mic the Maz 18 and play away, because big amp tone and soul is all there. This is also a great amp for jazz guitarists, whether you're looking to replace a small blackface amp or looking for an amp with enough complexity for fusion.
The Maz 18 is an amp that every Strat or Tele player will love, but it's not only for single coil players as humbuckers are right at home with the Maz 18 too. You get great drive sounds at higher volumes or the ability to use the Lo input for cleaner humbucker sounds. With a master volume and full EQ there is plenty of room for dialing in your desired tone. The "Cut" knob may be the most useful and versatile tone shaping tool on any guitar amp. Throughout its range, it produces a large variety of sounds to satisfy players using all guitars for most every style of music. The "Cut" knob is best used after the EQ is all set; turn it up for extra edge, turn it down for a more vintage sound.
The Maz 18 has the perfect combination of front end drive and output tube distortion. It has a wonderful 3D reverb clean tone, matched with the sweetest top end response and tightest bottom end in a lower powered amp. All this has made the Maz 18 our most popular selling reverb combo to date.
The front panel features Volume, Treble, Middle, Bass, Reverb, Cut, and Master. The back panel features a 4,8, and 16 ohm speaker out. An effects loop and our EQ bypass function is also standard. The footswitchable EQ bypass gives a great lead boost which effectively makes the 18 a 2 channel amp. The 18 is powered by a pair of cathode biased EL84s and a 5AR4 rectifier.
The Maz Jr. is 'King Chameleon' in my book, ruling over Sonic Flexibility in the land, having Vox, Marshall, and Fender sounds at its disposal. Simply put, the Maz Jr. is the Swiss-Army Knife of amps. The Doc tells us on his DVD, that the Maz Jr. is his best selling amp.
When you consider all of the outstanding amps that the Dr. makes, that fact should speak volumes as to what a truly magic amp, that the Jr. is...
The Dr. Z Amps DVD: www.humbuckermusic.com/drzampsdvd.html
Note that most of the comments I have here, are not from me.
They were nuggets posted by various Z-Brothers.
Tube lessons for the Maz 18 Jr.
The Maz 18 Jr. NR Model:
V1 - JJ ECC83-S (Preamp tube)
V2 - JJ ECC83-S (Preamp tube)
V3 - Sovtek 12AX7-LPS (Phase Inverter tube)
V4 - JJ EL84 (Power tube)
V5 - JJ EL84 (Power tube)
V6 - Sovtek 5AR4 (Rectifier tube)
The Maz 18 Jr. Reverb Model:
V1=ECC83-S (Preamp tube)
V2=ECC83-S (Preamp tube)
V3=12AT7 (1/2 used as a driver before the reverb tank, 1/2 used by reverb summer.)
Reverb tank info ( Older: Accutronics 8AB3A1B ), ( Newer: P-RMOD-8AB2A1B ).
V4=12AX7 (Used in a dual Triode parallel configuration as the Reverb recovery stage.)
V5=Sovtek 12AX7-LPS (Phase Inverter tube)
V6=JJ EL84 (Power tube)
V7=JJ EL84 (Power tube)
V8=Sovtek 5AR4 (Rectifier tube)
Various plagiarized posts from the board...
Preamp tubes:
Eddie wrote: I find the reissue Tung-Sol 12AX7's to sound great in V1 of my MAZ even after comparing the tone with some more "hi-brow" tubes. I think I've tried about 15 various brands...
www.kcanostubes.com/content/tung-sol-reissue-12ax7
www.tubedepot.com/ts-12ax7.html
Russell wrote: I just put a set of the Tung-Sol reissue 12AX7's in V1 and V2 my 2003 Maz Jr. NR 2x10.
I use them in my 1x12, but this is the first time that I put them in the 2x10. These tubes sound sooooo good.
Myles latest testing on the 12AX7 Tung Sol Reissue: la-economy.blogspot.com/2012/02/tube-test-12ax7-tung-sol-reissue.html
Eddie wrote: I have had many tubes in V1 and V2 in my MAZ. Can't say I've ever owned any of the holy grail tubes like Mullards or Telefunkens, but I have had several GE, RCA, Tung Sol, etc. All just a matter of taste as they say.
It is true that your Z amp will highlight the characteristics of whatever tube you put in V1. There isn't a lot of unnecessary circuitry in a Z amp, so the tubes are it. NOS or ANOS tubes are fun to roll in your amp, but don't completely rule out some of the new production tubes.
These are still one of the best bargain newer tubes out there, imo:
www.kcanostubes.com/content/jj-ecc803s-10-12ax7-recession-sale
Also, the regular JJ 12AX7 is good if you want to make a bright amp darker, but my ears don't really like them in V1 of my MAZ Jr. anymore.
Right now, I have a Shuguang 12AX7B in V1 of my MAZ. I may be in the minority, but I love the way these cheap Chinese tubes sound in V1!
The Tung-Sol reissue tube (Myles has written a lot on this one as it has gone through various brandings) is a decent tube. Still less than $15 almost everywhere.
Basically, it's hard to go wrong with NOS, but don't overlook some of the cool new tubes out there. Most new might be junk, but there are winners for any given amp and what you are trying to accomplish tonally, imo.
Have fun tube swapping!
Eddie
Myles latest testing on the JJ803S: la-economy.blogspot.com/2012/02/tube-test-jj803s.html
benttop (Steve) wrote: Maybe I'm crazy (check that; I am crazy), but I recently spent a whole lot of time and money changing out all the tubes in my maz 18 jr. and couldn't find anything I liked better than what she was born with.
All sort of combination's in all positions, except the rectifier. 12AX7, 12AT7, 5751, LP's. GE, RCA, Sylvania, EH, Mullard, Telam, Polam, etc., etc.
I know everyone's tastes are different and it was a pretty interesting albeit expensive and time consuming exercise but in the end I have to say I still prefer the stock tubes the Doc picked out.
I found a lot differences between the various tube types and manufactures but to me the biggest change in the amp came when I tried various phase inverter tubes. Those LP's the Doc uses rock.
I was really very surprised. I actually talked to the Doc during the process do discuss my project and thoughts. He kinda of laughed and basically said; yep.....smart man.
Of course that's just me and ymmv etc, etc.....
cheycaster wrote: One word for Maz jr owners......KCA nos RFT's in the V1,V2....that is all!
Mostrummer wrote: A 5751 tube can be swapped for any of the 12AX7's (V1 or V2). This will give more clean headroom.
The cleans will stay really fat sounding. Stevie Ray was reported to do this in his Fenders.
Andy 67 wrote: I have a NOS JAN Philips 5751 in V1 in my MAZ Jr. R and a NOS RCA 7025 in V2, and I think that they complement each other very well. Tons of tone!
teleric wrote: I like running an RFT in V2. Since V2 is the extra gain stage responsible for driving the preamp (and has less of an impact on your tone than V1), I like to use a pretty "gainy" tube there - the RFTs deliver.
mazmaster wrote: Been using the high gain option from Doug's Tubes (the best!) for many years in most of my amps.
In the Maz, I use them in all three slots and feel it's the only way to go with this amp! Highly recommended.
1juicy1 wrote: After a couple weeks of playing the high gainers I'm really digging them. They really help push the Maz over the top!!
*Update: I just ordered a NOS RFT 12AX7A and it tested at 107/107.
The Hi-Gain JJ's were 105/105 on the box. Nice but a tad brittle sounding.
The RFT is supposed to be a great match for the Maz and a touch darker to tame the highs.
It's what Mike at KCA recommended along with a 5R4GYB NOS Rectifier Tube for more breakup and compression.
Myles wrote: You might want to pull those ECC83S tubes out of V1 and V2.
Look for a medium plate USA tube such as an RCA, GE, Sylvania as used in Fender black face amps in the sixties or a Mullard (if not too pricy).
V1 first. V1 and V2 if you can afford it.
trevorb wrote: I have been wanting to try a lower gain tube in V1 just for fun. Well I live close to Eurotubes and asked what options were out there. Those guys are always great and gave me a killer breakdown.
Just so happened they recommended trying a 12AT7 and I had a spare. Threw it in V1 and moved the gold pin 12AX7 from V1 to V2.
I can't believe how much better this amp sounds. It didn't loose any of the touch dynamics, and to my ears it made the amp sound worlds better with both volume and master dimed. I know I have heard some of you share about your similar experience with this same tube change and I am here to say thanks for sharing, I am so glad I listened!
Love this amp more everytime I turn it on.
Note: Using a 12AT7 will work for decreasing the gain, but the 12AT7 has a different set of plate family curves, which produce a slightly more bassy output.
Myles wrote: A 5751 is a wonderful tone generator (front end tube) but a 12AT7 is not. The gain is about the same but a 12AT7 is harsh.
Recently evaluated Preamp tubes by Steve Fryette.
12AX7A/7025 Shuguang: Well balanced tonal spectrum, low noise with moderate microphonic tendencies, easily selected out in production. Excellent for clean and overdrive sounds.
12AX7WB Sovtek: Lower gain, somewhat less bass response, and not as bright as Shuguang, but not dull sounding. Very low microphonic tendencies.
12AX7A Tung-Sol: Very good gain and low microphonics. Nice low end. Somewhat forward in the upper mids. Basically a fatter higher gain EH 12AX7. Appears to be an EH with a different getter.
12AX7 EH: Very good gain and low microphonics. Less low end than Tung-Sol and not as smooth on top. More pronounced in the upper mids.
12AX7LPS Sovtek: Similar to the EH but generally a little less of everything. Nice balance and a good alternative to the Shuguang if you like less top and a little more mid.
12AX7/ECC83 JJ: Works well in Valvulator 1, which was surprising, since it did not fare as well in prior testing. Apparently the hum and microphonic issues have been addressed. A little darker sounding than the WB. When used in the amplifier V1 stage, this tube performs similarly to the WB, but the mids are more pronounced, the top end is dullish and overall somewhat harsh sounding for high gain settings.
chetz wrote: The 12AX7 is so widely used in guitar amps, I thought I would throw this up to help explain I the different variants.
I am a big proponent of NOS tubes but they are risky buys at times and you better be able to test them.
They have made a significant audible improvement in EVERY amp I have put them in.
A Tube marked ECC83 is exactly the same tube as a 12AX7. It is simply the way the were marked in Europe.
A 7025 marked tube is a low noise industrial version of the 12AX7.
A 5751 is a U.S. military spec 12AX7, and has about 30 percent less gain typically. You can beat the hell out of them though.
A 6681 is another industrial tube, and a step up from a standard 12AX7.
Tubes marked ECC803S, E83CC, E803CC are premium versions of the ECC83. Telefunken, Siemans and occasionally Mullards can be seen with such markings.
S stands for 'Special' or screened for low noise.
You will also hear about Longplates ( 17mm ) and Shortplates ( 14mm ). The longplates are considered more desirable and are much rarer and more expensive.
Between Smoothplates and Ladderplates, Smoothplates are generally considered to have more definition and detail.
I hope this helps some of you, it was confusing as hell to me at first.
Peace,
Jeff
Myles site on preamp tubes: www.guitaramplifierblueprinting.com/12ax7.html
Also...
Preamp Tubes - The most critical, least expensive, most overlooked tubes in your amp: la-economy.blogspot.com/2010/09/most-critical-least-expensive-most.html
Myles knows his stuff!!
A Microphonic Preamp Tube
Reverb tubes:
You can change the character of the verb a bit with tube swaps.
Eddie posted a downright beautiful clip in the audio section of his MAZ with a 5751 tube in V3 and a 12AX7 in V4: ztalk.proboards.com/index.cgi?board=soundfiles&action=display&thread=28465
Eddie wrote: I tried 12AU/Y/T all in the driver slot of my MAZ. Each does change the reverb a bit. Really just seemed to make it weaker in that you'd have to run the control higher to get the same level.
The tone may have changed a little, but not a whole lot.
It WILL change the feel of the front end of the amp - even with the reverb off. It's subtle, but running a hot 12AX7 in 3 makes a difference.
In the end, I went back to a 12AT7 in V3. I like it best - both before and after I had changed the tank from the old accutronics to the newer MOD tank.
Surf on, bro!
Eddie
Tip: To tame an over active Reverb Tub, try a 5751 in V4 ( Reverb recovery stage ).
The Phase Inverter tube:
The Phase Inverter tube, is located closest to the Power tubes.
Use a tube with balanced triodes for the PI.
Dr Z recomends a balanced Sovtek 12AX7-LPS (long plate spiral filliment).
Mike at KCA tubes can help you out with that: www.kcanostubes.com/content/sovtek-12ax7-lps
The Doc designed the Jr. to use the 12AX7 LPS as the Phase Inverter.
Tip from the Doc is to return the Jr. to it's original tone, replace the PI with another LPS.
For a little more clean headroom, try a balanced NOS 12BH7, or 5751. That will also smooth things out some.
Here's some General Guidelines on tube gain. The tubes being produced today have very inconsistent gain, from tube to tube.
The only real way to know for sure, is have them tested. It really is a crapshoot...
12AX7 = 100% or the standard 12AX7 spec. (1.2 mA at 250 volts with a -2 volt bias.) That reference spec also applies to 12AX7 / ECC83 / 7025 tubes.
12AT7 = Has 70% of the gain of a 12AX7.
12AY7 = Has 44% of the gain of a 12AX7.
12AU7 = Has 17% of the gain of a 12AX7.
I don't know the number for 12BH7 but it is very low.
My fave is a NOS 12AY7. A 12AY7 is not going to be a bright or snappy tube. It's all compromise.
It's hard to say exactly how much extra clean headroom you'll get from the 12BH7 PI swap; it depends on other factors like your guitar's pickups, your touch, etc. but it's a decent amount.
** Note: Changing your stock phase inverter tube over to a NOS 12AY7 will give you more clean headroom, but the amps overall volume will be less than before.
bluzman wrote: To me the LPS in the phase inverter gets too bright with my Teles.
I've tried the 12AX7-LPS in V3 and it sounds very good, but for my tastes, I still prefer high gain JJ-ECC83S in all three slots. (V1, V2, and V3 on NR Model.)
I really like the GT12AX7M in V1 and in the PI spot as well.
Scott wrote: New rule for me - I like the gain of an actual 12AX7 in the PI position. Running a tube with too low of a gain here, can change how your Cut Control will need to be set, and the level of volume required to let the amp's sound open up, probably first requiring both Volume and Master settings to be past 12:00. A 5751 PI does not have enough gain for me, and caused me to run my Cut Control from a normal 9:00 position, to a new 3:00 position to sound close to the same.
The JJ ECC803S 12AX7 is a long-plate tube, and I read somewhere they work nicely as PI tubes. Try it and see what you think.
JJ ECC803S ( 12AX7 ): thetubestore.com/teslaecc803s.html
"Description: The latest preamp tube from JJ is a very long plate classic European style tube with thick mids and a little more high end than the ECC83S. Great in V1 or in all positions in vintage amps. Also available matched or with balanced triodes for phase inverter use."
JJ ECC803S ( 12AX7 ) Gold Pin: tubedepot.com/jj-ecc803g.html
"Description: The Gold Pin JJ ECC803S is also designed to be a premium version of the long plate JJ ECC83S. The Gold Pin tubes are a bit smoother in the high end and a bit richer in harmonic content so they are an excellent V1 tube in guitar amps. (Not recommended for combo amps) They are also available with matched triodes and with current balanced triodes."
Myles wrote: Gold pins will stop the corrosion on the surface of the pins on tubes sitting on shelves in storage. Once the pins are in contact with a socket that is not gold plated there will still be corrosion on the socket. Two dis-similar metals will generally corrode when they contact each other. Gold pins - cost virtually nothing to produce as the process is so simple and the plating is so thin - NO benefit with greater cost. One of the biggest scams in the tube world.
A 12AY7 in the phase inverter spot will give lots of clean headroom, as will a 5751 in the PI slot.
You will get more clean headroom with the 12AY7, than the 5751, but both give more clean headroom than the 12AX7.
For max clean headroom, also make sure your output tubes are fresh...
I do not select my phase inverters based on Gain, and Transconductance is also something of a false indicator for me. For a phase inverter, I look at plate current and plate resistance. If the plate resistance is within spec (62.5K at 250 plate and 2 volt bias) then then tube has a good chance of being excellent. If the plate current is too low or too high it means that the tube has some sort of defect and the plate resistance is not correct or there are other problems. Since the phase inverter drives the output tubes I look for current rather than TC or gain.
I also look for rise time with a curve tracer. Depending on the application and style of the player I may desire a faster (tighter) or slower (looser) response. Chad Weaver (Brad Paisley) has a drawer of tubes with different characteristics that he swaps in and out of amps depending on how Brad feels in a given venue.
Look at the old Groove Tubes 12AX7M reissue, the later production runs had the highest TC of any 12AX7 ever made. It also had the highest plate current. But... the plate resistance was half of design spec, or less, in most tubes. This gives very high TC, high plate current (tube runs very hot) but VERY low true gain in circuit and there is more crosstalk between the A and B sides of the tube.
A classy and articulate description of this would be: Crappy tube.
A 12AT7 has about the same actual gain as a 5751 but has about ten times the plate current at 10mA vs 1.2mA of the 5751. It also has a very fast rise time. In Fender tolex era amps it was picked for clean headroom and good drive current to push a quad of 6L6 tubes.
A simple blackface or silverface trick to make a Fender more aggressive is to swap the stock 12AT7 with a 12AX7. Plug and play... no adjustment needed.
Telefunken 12AX7's are not a good choice at any cost for a phase inverter from my point of view. Most have very low plate current, very low transconductance. But, with plate resistance of 80-100k which was common, their true gain in circuit was over 100 in many cases. They are the highest gain 12AX7 / ECC83 tubes made. Because of the high gain they were very responsive but the high gain made them more prone to physical microphonics.
Whether you run a 12AX7, a 5751, a 12AT7, etc..., is really a matter of design, and personal taste with countless options.
I generally prefer long plate tubes in the PI slot (my personal general taste much of the time but not all the time).
This can be a Sovtek 12AX7LPS, JJ 803S etc.
It need not be expensive but have the vendor assure it does not rattle at all and assure that the plate current is at least 1.1mA (1.2mA is spec).
Most today are 0.8 - 1.0mA and we don't want a weak phase inverter straining when it tries to properly drive the output tubes.
In many amps it is not as much the output tubes you hear distorting, it is the phase inverter taking a dive because it is weak.
If you want to be sure things will work properly and for many years you can go the NOS route on the PI.
If you decide to run a NOS 12AX7, you can't go wrong with RCA, GE, Brimar, Mullard as just a few examples.
One more side note on PI replacement... 6L6s are hard to drive. So are 6550s and KT88s. EL34s are not too bad but amps with master volume controls can tax the phase inverter on EL34 amps depending on setting and depending on the master volume being pre or post an area of the cicruit.
EL84 tubes are very easy to drive. In the case of the MAZ Jr. the PI will last many output tube changes.
I have seen no change in specs on PIs in MAZ, Mazerati, or other Dr. Z EL84 based amps over a dozen output tube changes, unless the PI had some sort of quality defect issue built into the tube originally.
A pdf file about phase inverters containing quality info:
The most important tube in your amp? The Phase inverter! www.guitaramplifierblueprinting.com/files/Phaseinverter.pdf
"Going from a 12AX7 to a 12AT7 in the PI (phase inverter) will yield a change in output tube distortion, touch, and output dynamics in most amps.
Is this because the gain is lower in the 12AT7? 10% yes perhaps.
The lower gain is a factor but the larger factors are:
• We have almost 10 times the current available to drive the output tubes before the phase inverter starts to break down.
• We have a transconductance of 5500 vs 1600 of the 12AX7. Keeping this simple, it means it takes a lot less input signal for a given output signal."
The Power Tubes:
The Maz 18 Jr. is cathode biased, so buy a matched pair and there will be no need to have the amp re-biased.
Carry a matched set. If you replace a single tube it will not be matched, even if it came from a set that was matched to the original set, as these cathode biased EL84s wear very fast.
Question: How many hours do EL84 Power Tubes last at gig volume levels, in a Cathode-Biased amp?
Myles wrote: This varies on amp and personal taste. I know folks that play for a year or more on EL84 tubes in cathode biased amps.
I also have folks that change their output tubes after ten shows, about 30 hours.
I notice a difference. Most everybody around when this is done notices a difference.
As more hours are put on a tube the reliability will go down.
If you are playing a 20,000 seat venue the reliability factor might be a consideration if you favor a particular amp in your setup even if you have many other amps on stage.
In the end it is personal taste.
A handy 'EL84 Tube Type Review' link, courtesy of TheTubeStore: thetubestore.com/el84review.html
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A lot of us really like JJ's for EL84 tubes. www.eurotubes.com/
www.tubedepot.com/jj-el84.html
rickc007 wrote: I ordered some JJs and some TAD's. First put the JJs in, and got a bit more power.
Tried the TADs, and first thought was "more balanced". JJs were a bit more in the bass and mids.
Then I got to missing the extra low end oomph. Put the JJs back in, and I likes them.
Liked TADs in another amp I had, but JJs do it for me in the Maz.
shouldb (Pete) wrote: Me too - on my third set of JJs and love them.
beanbag wrote: JJs are my "goto" El84. In my experience, they are the most consistent in performance and reliability of any new production.
Andy 67 wrote: +1 on Eurotubes and JJs!! Tons of tone!
"z" Steve wrote: For about 5 years I've used Bob at Eurotubes to by my JJ EL 84's for my amps requiring those tubes. I have also used Mike at KCA for trying the TAD EL84's just for a change. Both brands have worked great and I have not had a failure or issue with either. Both Bob & Mike will set you up with tubes to your liking as far as breakup - early or late.
On ( Aug 26, 2011 ) - DRZ wrote: OK guy's here's the skinny on JJ tubes: Over that last 6 months I have seen a noticeable decrease in quality. I currently have over a 25% rejection rate on JJ 12AX7's, and the same can be said for the JJ EL 84's.
It is a shame because JJ's were the most rugged tubes on the market, but they have slipped, boy have they slipped.
I have reported this to my US importer and just received some lip service and a bump in cost of 12AX7's, probably due to my large number of returns.
And speaking of returns were do you think my rejects go...
So what is amp builder to do, well I re-evaluated Sovtek EL-84-EH's and like the results.
Tighter builds with less filament rattles, and much less harsh ( upper Mid Response ) then the available JJ EL-84.
In all the new facelifted MAZ line ( that is ones with the new front panel ), we are using EL 84-EH's with great results.
I will be using more EL 84 EH's , so look into them when it's time to re-tube.
As for the JJ 12AX7 I still like them in the first position of most amps but have switched to Chinese 12AX7 HG+ in tone stack driver pos #2.
DR.Z
dobro1 wrote: This is a topic I can relate too for sure. I went through 3 sets of JJ's and they all went bad within a month one set 2 days. I was thinking there must be a problem with the amp. I have used JJ's for a long time and they always sounded great and never had quality issues like that. I bought a set set of EH and they sound great and been using them for 6 months with no problem the only thing I noticed is it seemed like I lost the slightest bit of volume with the EH but the quality of sound is excellent.
abandoned wrote: I asked Brent at Dr. Z and he said that they prefer EH cuz JJ's "have something harsh about them", that you can't really dial out.
He said using JJ's sparingly is ok but using a lot of them in one amp is not a good idea... due to the harshness.
BritInvasion wrote: I gave up on JJ's after red-plating 2 sets in a row. I am using TADs now and really like 'em.
I've heard EH are generally pretty good, and like others say here a little darker than JJ. But I don't have first-hand experience with EH.
mazmaster wrote: I have set of older Groove Tube JJ EL84s, and a brand new set of perfectly matched JJ EL84s from Ruby Tubes via Doug's Tubes, and a brand new set of TADs.
All of which I tested yesterday.
I found the older JJs to be my favorites. They were warmer, fuller and less harsh then the new JJs and the TADs.
The new JJs were surprisingly bright and a little harsh. The TADs sounded a little metallic and tanky in the mids to me with OD pedals.
I got a chance to compare my older JJ-EL84s, to a brand new pair of JJ-EL84s, and a brand new pair of EH-EL84s.
I preferred the older JJs to the EH and new JJs.
The new JJs were VERY bright, and the EH mids didn't blend well with the mids of my main OD pedals.
I'm sticking with the older JJs till they die or get dull. They have a fantastic blend of smooth mids and highs and no harshness.
I don't know what's going on with JJ, but they really do seem to be going downhill and with no good alternative that I've found yet.
flapp wrote: I recently returned a Set of JJ 84's to a dealer and threw another set in the trash. The last two quad sets I have ordered have had problems. Maybe it is bad luck. Maybe I keep getting sent the same tubes, but I was talking to Don, very anxiousely about my AMP problems...in the end it was power tubes. JJ84's.
One set lasted about 2 months and then started cutting in and out. The next set were noisy and completely changed the feel of my 38.
So I will try the Electro-Harmonix 84's recommended by the Doc.
Not all my JJ's have been bad of course... Just recently it seems.
Myles wrote: JJ used to be the tube to use, the good old tube that lasted a long time and sounded very vintage.
Over at the shop the JJ 803S and all of their output tubes have shown a decline in specs, wider spread in tolerances and have been more physically microphonic in the past three to six months.
The best tubes today seem to come from Tom McNeil at Magic Parts ( Ruby Tubes ), He has some very nice 12AX7s, and EL84s. magicparts.com/main.htm
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Here is the Electro-Harmonix version of the EL84 power tube, that the Doc is going to in 2011: thetubestore.com/ehxel84.html
evilsmooth wrote: Compared to the old JJ, the EH sound darker and seem to have less power as if my amp goes from a great 18w to a 10-12w...
I won't by another matched EH anymore. I'm looking on TAD...
number9 wrote: I swapped out the old JJ EL84's with new EH EL84's today. The EH's are slightly scooped but more pronounced in the low-mid frequency, they don't jump out at you like the JJ's. I could run the CUT knob higher with the EH's, but some might miss the high-mid frequency articulation of the old JJ's. The EH's have a great lively feel, some moderate spongy compression, and they sit back in the speaker nicely besides some low-mid frequency droning. For those of you using boost pedals ( Beano Boost, AC Booster, Tim etc. ), or drive/distortion pedals ( TS-9, BB Preamp, Hellbender etc. ), the EH EL84's might be a great pick. I actually preferred the way the TS-9 Silver sounded with the EH's, it balanced things out and sounded as good as ever.
Note: These tubes have a slightly larger diameter than other EL84 tubes so they can not be installed into some Marshall DSL201 or DSL401 amplifiers, some reissue Vox AC15 amps, and Bad Cat amps.
Note: One Maz Sr. member, abandoned wrote: Well I recently had my Maz38 Sr. retubed with ElectroHarmonix EL84's hoping they'd be an improvement over the JJ's I had in previously. And I was met with unexpected results. The moment I received my EH's and put them in and turned on the change in tone was very apparent...
The EH's did not have near as much treble and presence as the former JJ's. The tone was also more woody.
I used to run my Cut & Treble very low - like around 10 o'clock. But since the EH's went in I've literally been running those controls at 11-12 o'clock. Which is a pretty big difference - especially on the Cut control cuz its so bright.
I personally like the tone of the JJ's better - all the brightness and liveliness and bounce of the JJ's was so much better in my opinion. My tone was so much duller after the JJ's got pulled out for EH's.
Now here's the tricky part though - the JJ's are so unreliable. I went through 2 quartets of JJ EL84's in just a few months.
They had issues like major white noise, crackling and hissing after just a couple months of use.
So cuz of their lack of reliability I've had to go with a different brand name. I chose EH cuz they are what come stock with Z's now but I'm not fond of their tone.
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I'm also still a fan of the TAD EL84's. These tubes along with the Sovtek 12AX7-LPS in PI are just ear candy.
www.kcanostubes.com/content/tad-el846bq5-str-singles-pairs-quartets
"Smoother and less bright than the JJ's. Good if you need to tame that Dr Z or other amp."
BritInvasion wrote: I'm using TAD EL84's in my Maz 18 Jr and I agree , they have a great warm sound. Took the harshness out of the highs I was getting.
teleric wrote: I recently put a new set of TAD EL84s in my Maz 18 - nice sounding tubes - the sparkle is back in my Maz.
twoscoobysnacks wrote: +1 on the TADs. I believe they definitely tamed the brightness a bit on my Maz Jr.
bluzman wrote: The TADs are now using a thicker glass. I've bought quite a few of the EL84, 7025 and 6V6. I'm going to put a quad in my Remedy as that is getting noisy.
I think it comes down to QC on the testing and at least the TADs have been consistent from my experience.
cheycaster wrote: Man I am loving the NOS RFT's i got from Mike at KCA tubes. I just stuck in one of the pair of TAD'e #6 I got from him too and I love them! They are nice and full and smoother sounding to me and my CS Clapton with CS Fat 50's really shine now as these tubes kind of rolled off some of the higher /harsher frequencies from it. I am trying them out in my 01 Maz Jr. Reverb combo with a well broken it V30. they are #6 on the GT scale if that means anything. But just the RFT made the difference for me to take notice and think.."WOW" me likey!
Myles wrote: The TAD stuff is made in the Shuguang factory in China. They are quite nice. TAD's have a 42% shorter life than a spec JJ in stress testing before 20% drop in plate current output is noted. The TAD is a Chinese built tube and shorter life in some output tubes is to be expected. Looking at how long some folks run their EL84s this might not be a factor at all for a lot of people as many are running quite a bit lower than 20% down due to tube replacement that is put off. Bottom line ... If you like how they sound that is what is most important. On shorter life ... most folks keep the same output tubes in use long after their tone and response has degraded.
Sort of like watching a child growing up, you don't notice a change unless you don't see them for years.
In amps you don't hear how much things degraded until you plug in a fresh set.
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nicholas wrote: The Mullard El84's (New Production) just sit right with me: store.tubedepot.com/mu-el84.html
They still have all the chime of a JJ or similar but when pushed they are real creamy and smooth.
They do seem to have less headroom in general, so if loud clean is your thing you might not like them.
I play mostly blues and blues based rock so they fit my needs perfectly.
In other amps I have run them for at least 20 hours a week and replaced every 3 or four months as preventive maint, only. No failures yet.
strictlydrz wrote: I've had a pair in my Maz Jr for several months, from Tube Depot - I like them too. Seem a little less smooth than the JJ's I've had in the past, which is fine.
crxsh wrote: Just picked up a set of these Mullards and finally got to do some swapping today, so I thought I'd put my 2 cents in here:
The JJ's seems to have more gain to my ears, but strangely enough, more clean headroom at the same time. With my Maz, I could have the volume knob around 1:00 with the MV around noon and still keep it pretty clean. Conversely, the Mullards start to break up a little right around 10:30 on the volume knob... and by 12:00 you're easily into some audible gain territory.
When cranked, it seems to me that the Mullards don't have quite the same aggression as the JJ's. Where the Mullards are smoother and a bit "saggier" in texture, the JJ's have a more crisp bite to my ear. More compression and, I do believe, a bit more gain.
Both are nice and choosing between the two sort of depends on what sound/texture you want... but those are my findings.
nicholas wrote: I'm still stickn' to the Mullards in my MAZ R. I recently tried some JJ's and TAD's.... The Mullards just do it for me. Smoother treble and less aggressive, I like it.
I find I can run the cut much higher ( almost maxed ) and still keep it smooth and thick.
I'm still using the same old NOS RCA 5V4 Rectifier also.
I find I have plenty of headroom... master full... volume at 10:30 with a LP. Thats clean to me.
byrdland wrote: As far as output tubes, I have tried JJ's, TAD's, Brimar and Mullard re-issue. The TAD's and Mullards seem warmer, less bright than the others. I seem to prefer the Mullards.
number9 wrote: Just wanted to give you guys a heads up/FYI that the new production Mullard EL84's and 12AX7's sound really good. So far I've tried old/new JJ's, new EH, and new Mullard's in the power section. They've all been pretty good, no bad experiences, but the Mullard EL84's have a silky smooth ear pleasing sound, plenty of nice harmonic detail, and are DEAD quiet, great for folks like me rockin' the reverb model. The Mullard 12AX7 sounds great too, a little less gain but more detail and less harshness compared to the JJ that was in V1. I could have simply lucked out with this pair, but so far so good, really good! Hopefully they keep it up!
My current tube arrangement for anyone that's curious:
V1 Mullard 12AX7
V2 JJ 12AX7
V3 JJ ECC81
V4 Sovtek 12AX7WB
V5 Sovtek 12AX7LPS
V6/V7 Mullard EL84's
-number9
zorange (Zach) wrote: I'm using Mullards and have been for a while now!
I love love love love their sound! With my MV around 2 or 3, these things sound so good!
I love their overdrive sound as well. Not brittle or spikey in any way.
Only one bad tube from Mullard when ordering from thetubedepot. And that's out of 4 tube changes now.
peterd79 wrote: I just dropped in two Mullard EL84s and i've got to tell you that I'm soooo in love with my Maz Jr. It's nuts.
I just love the Mullards in this amp...
The stock JJs are great but for me the Mullards really set this up for a blues box that is just incredible.
Myles wrote: These have nothing to do with any NOS Mullard design, and are little more than a stout and dark Sovtek EL84.
They are a very reliable tube and that is a very nice factor. They have a longer service life than the TAD offering in stress testing. They are a bit dark for my taste.
Some folks may prefer them being a bit darker, as many EL84 amps tend to be voiced quite bright.
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Eddie wrote: With the quality of JJ tubes slipping lately and some having trouble with EHX, is it maybe time to go back to Sovtek EL84 tubes?
www.tubedepot.com/so-el84.html
I know ten years ago, nobody liked them for tone, but they were at least durable. Maybe they are a little better these days?
thoughts?
Eddie
headshrinker (Marc) wrote: Looks like I'm in the minority, but I love the Sovtek EL84s.
Knock on wood, I have never had one go down on me and as a rule in bright amps they warm up things and go into distortion quicker than than JJs, without that upper mid peak.
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Tip: Don't buy the Genalex Gold Lion RI EL84's: ztalk.proboards.com/index.cgi?board=tubes&action=display&thread=21616
They seem to have a high failure rate, and rather expensive: thetubestore.com/goldlionel84.html
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New JJ EL844 tubes w/ 30% less output for Maz: www.amazon.com/JJ-EL-844-Vacuum-Tube-Matched/dp/B004DF0EPY/ref=sr_1_1?ie=UTF8&s=musical-instruments&qid=1298355807&sr=1-1
The JJ EL844's Data Sheet: www.tube-town.net/info/datenblaetter/tubes/jj/jjel844-tt.pdf
Dr. Z speaking on how the torture test went with the JJ EL844's, using the Maz Jr: ztalk.proboards.com/index.cgi?action=display&board=maz18&thread=37862&page=1
DRZ wrote: OK I did more testing and the results are:
The EL-844 held up to the torture testing quite well.
What they will do long term in the real world of gigging, only time will tell.
They sound very nice, less top end cut and more low end fullness.
Which some might like.
But the lower wattage isn't very noticeable, you almost have to ask yourself is that really lower volume.
Again they didn't do as well in the Ghia, I don't know why maybe the higher bias resistor, conjunctive filter, and much lower plate voltage, all added up to loss in good tone IMHO.
The difference in output power is less then one click on the Air-Brake.
So not sure if that justifies a purchase, but for 30.00 a pair they might be a nice subtle change of pace.
DR.Z
1juicy1 wrote: Thanks Doc!! That is what I found, one click on my brake lite and the tone is a subtle difference. But it is different.
Especially nice for us higher preamp volume players!! Combined with the high gain JJ12AX7A's its a big difference!
greenblues58 wrote: I ordered a matched pair for my nephews Laney LC15 and thought I would pop them in my Maz 18 to try them before fitting them to the Laney.
Bit of a surprise as they sound very fizzy when ran with the master high,which I tend to do,and lacking in bass and treble overall and slight difference in volume.
Tried with different guitars all sounded as above.
Stuck them in the Laney in place of its stock issue JJ EL84's, and wow it sings like a bird with my nephews Les Paul studio pro plus which has burstbuckers.
It did not sound bad with the EL 84's, but they were definitely on their way out.
Mark N wrote: I have a set in my Maz Jr... I like em... No real difference in tone...
Might be a slight volume difference overall. No complaints here!
I have only gigged the amp a couple times since getting them and I was more than pleased with the tone!
I have tons of bass, treble, or whatever I need.
1juicy1 wrote: I Love 'em in my Maz! On my second set in fact!
joebou wrote: I also really like these tubes, but I have also changed my recto to a 5y3, I was in search of the proper tone vs volume situation, and I seem to have found it with this setup. I also put a 5751 in v1. All of these small changes added up to a huge difference in overall tone, and reduced my stage volume dramatically. I'm lovin it.
wubberdubber wrote: I put a quad of these in my MAZ 38 and did a few gigs with 'em.
I didn't notice much difference except in the low-end response... Seemed a little looser than the JJ EL84's that had been in there.
Myles wrote: I truly feel it is just a substandard EL84 from their regular product line.
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Question: Will a 7189 Power Tube work in a Jr?
www.kcanostubes.com/search/node/7189
YES, a 7189 will work fine as a replacement for an EL84. This is the "industrial" version of the ( EL84 / 6BQ5 ).
The difference with pinouts between the 7189A and the 7189 are all the same except that the 7189A has:
Pin 1 is connected internally to Pin 2 ( Grid )
Pin 6 is connected internally to Pin 9 ( Screen )
A 7189A would usually work in an EL84 amp too, but a 7189 might not work in an amp designed for 7189A.
There is one way a 7189A wouldn't work in an EL84 amp. If somebody was using pins 1 or 6 as a solder point for a resistor.
Some amps will use pins 1 or 6 to get more point to point going. (Fender comes to mind)
Will a 7189A work in a Jr? Unknown... The Tube Socket would have to be examined to verify that pins 1 and 6 were not in use.
Also, you can't use an EL84 in place of a 7189, in an amp designed for 7189's.
7189's have 400V on the screen and plate, and the 7189A has even more at 440.
The EL84/6BQ5 can only handle 300 volts, so they couldn't happily exist in an amp looking to send them an extra 100 volts or more.
It's putting EL84's into an amp designed for 7189's that you may get into difficulty because of the higher voltages.
A 7189 will run down to the same voltages as an EL84, but an EL84 won't run up to the same voltages possible as when using a 7189.
Telemanic wrote: One of my personal favorite tubes and a collecting passion, is the 7189A. In certain circuits it seems to defy the fact that it is basically a heavy duty EL84!
It EASILY handles it's rated 440v plate voltage (compared to 250v for EL84). The amps I have that use them usually are running about 465 + plate volts and they don't blink. Now here's the deal with them, Ive studied these suckers a fair bit and made some interesting discoveries: #1, In (almost) every case you can sub them for an EL84 requirement with great results. The exception is a Mesa .50 cal amp i believe and perhaps a rare few others that use pin #1 for some internal tie off's. In NOS EL84's, 7189, & 7189A, pin 1 and 2 are internally connected and cannot be used in those amps. Whereas new production EL84's do not have this connection. MOST amps don't care as they don't use pin 1 anyway, and can use EL84, 7189, & 7189A.
The most obscure fact about 7189A exclusively is that they ALSO internally tie pins 6 & 9. In almost all EL84 amps it is a moot point as pin 6 is not used in the circuit. Hence, 7189A will work anywhere an nos EL84 will, ... but not necessarily in reverse. In some old amps that run an ultra linear output tranny they actually use pin 6 for the screen grid, and thus a down grade to EL84 will not work, irrespective of the voltage req. SO to sum up, a 7189 or better a 7189A will give you a bit more headroom, beef, and big bottle sound than the EL84.
Two last caveats, ... European NOS 7189A's (Mullard etc.) do not tie pins 6 and 9! say what? I Have no idea why, but they decided not to follow the GE pin out schematic. I have a Quad of beautiful Mullard 7189A's that don't work in my stock wired Magnatone amp! And lastly the 7189/7189A is becoming nearly extinct ... which makes everything i just posted nearly moot! LOL! So Happy hunting, if you can find some they are a cool alternative to EL84, even if temporary. - Peace
** Note: We have yet to get a single report of a 7189A tube successfully being used in a Maz Jr.
This info was kept by me due to it's quality, and if proven that 7189A's do work fine in a Jr, it's future value.
Scott wrote: Myles,
I was looking around your site, and was wondering if you had ever posed any words of wisdom, or your general impression, of NOS 7189 tubes. I have a set of NOS RCA 7189's and was wondering what you might think of them.
Myles wrote: These are terrific.
Think of an EL84 that can tolerate much higher voltages.
The plate current output is the same as an EL84 @ 48mA at standard book voltages but the design voltage max on the plate is 400. On the grid 300.
Plate Dissipation ............... 12 W
Grid No. 2 Dissipation .......... 4 W ( 16 watts total )
The EL84 / 6BQ5
Plate Voltage .................. 300 V
Grid No. 2 Voltage ............ 300 V
Plate Dissipation .............. 12 W
Grid No. 2 Dissipation ......... 2 W ( 14 watts total )
Bottom line... they will run stronger. You also have more output by at least two watts (in pentode mode the screen and plate wattage is combined)
Most amps run EL84 tubes beyond spec at over 300 plate volts in most cases.
The 7189 handles these voltages with ease and the tube is more reliable as it is generally running well within its intended design range.
They also sound outstanding.
** FYI - There is a current production 7189 tube being made...
hitoverdrive wrote: I like demoing tubes just to see how they do in my amps circuit. I like to find out for my self how they sound and feel. I also like asking peeps opinion on them as well so I can save money through others experience paying attention to what amps they're using these tubes in and other variables. I pretty much know what I like in my 2 EL84 amps now. Every once in awhile I will try something different. I read the description given about the tube at the site selling them and then laugh. After that I'll pick up a pair and try them out if I'm interested.
Right now I'm demoing the 'Preferred Series 7189 ( Premium EL84 )': thetubestore.com/preferred7189.html
They are almost as much as my RFT's. So far they are holding up in the Monza. They have a bit of hair on them right now but they are not stiff. Lows are big, mids present and the highs not strident. I'm liking them so far. Good dynamics when rolling off guitar volume. The hair comes in when wide open and goes away when rolled off a little. My RFT's are smooth throughout. I'm running a Miniwatt 12AX7 in V1 and JP 12AX7WA in the PI. Anyways these are suppose to be rugged and long lasting.
rhoydotp wrote: Sending some "K" to texan2step & ajb20002 for the heads-up on this tube ... though I have to put more mileage on it, it sounds great so far. When I got the amp this year, I didn't bother replacing the GTEL84 that were in there. I think prefer the sound of this to the GT.
texan2step wrote: Glad to hear that you like them! I think these get a great chime but with a slightly warmer sound which I prefer. I hope you'll continue to enjoy them. I'm slowly replacing all of my EL84's in all of my amps for the preferred series. Happy playing!
Myles wrote: When comparing them to the common Sovtek EL84M heavy duty EL84, we may find little difference to justify the high cost.
Sonically, I do not like these in guitar amps as I find them not as articulate as some other EL84 types or NOS 7189 types but that is just my own personal taste and preference. Others may have the opposite feeling.
In a hi-fi amp they may be a good option as most hi-fi amps are not cathode biased. In a cathode biased guitar amp I don't think the duty cycle would be extended long enough to justify the high cost.
$25 for a current production (or out of production old stockpiled Russian surplus tube) is a bit out of line for my taste. We are not talking Mullard, Telefunken or classic NOS tube here.
Those 5,000 hour figures they state on the website? Probably obtained using standard plate spec voltages in a grid biased configuration. Guitar amps do not work in that manner.
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Myles wrote: Here is a bit of a wrap up on reliability testing of a few EL84 types:
Genalex - Gold Lion N709 / EL84 - Tube Depot has some real ones.
They comment: Originally made by Genalex in England, the famed N709 is once again available. Made in Russia to exacting standards, the new Genalex – Gold Lion is a true echo of the past. These Russian re-issue tubes do a great job of reproducing some of the magic of the original. Due to excessive current demands found in cathode biased amps (such as Vox AC30 and others), we do not recommend these tubes for use in these types of amps.
The above paragraph sort of says it in a nutshell. Not very long lived.
Short Life:
Electro-Harmonix EL84 EH
EI EL84
Medium life:
TAD EL84
Mullard EL84 / 6BQ5 New Production (a few internal changes possibly)
Long Life:
JJ EL84 / 6BQ5
Sovtek EL84
Sovtek EL84M (very dark tone, darkest of the EL84 types)
A Microphonic Power Tube
More Maz Jr. info continued on 'Reply #4' in this thread.
Any other words of wisdom on the Jr., please post them up!