Ask Myles or Chad - amp or live playing questions

[JASON (aka jgleaton)]

billyguitar said:

Might as well use the whole thing since we paid for it.

....OR in DR Z's case you have to LIFT that HEAVY amp/ transformer so "you might as well use ALL of it"!!

[sae2111]

This is just a general amp question and I would be glad to hear from anyone more experienced than I....
To this point, I have only used combo amps. I will soon be purchasing either a 6545 or a Delta 88. I have never had to shop for a cabinet so I don't really know what I need. At the moment I'm more concerned with practical issues than recommendations for those heads (though I would love to hear them). What do I need to know about different impedences? Are there basics about how they respond? For instance are there typical differences between running at 4 ohms and 16 ohms, or does it just depend on the setup? How is the output from the amp dispersed to multiple speakers? Since the 88 puts out a lot of wattage, what kind of speakers would I need to handle it? I see a lot of people who like 30 watt speakers. Would I need multiple speakers to spread out the output of the amp to avoid blowing speakers? I may not even be asking the right questions right now, but you have to start somewhere, and here I am. I may be asking for a two hour lecture to really answer the questions, but any tips or experiences that you feel would be prudent are much appreciated. Thanks for reading.

[Deleted]

sae2111 said:

This is just a general amp question and I would be glad to hear from anyone more experienced than I....
To this point, I have only used combo amps. I will soon be purchasing either a 6545 or a Delta 88. I have never had to shop for a cabinet so I don't really know what I need. At the moment I'm more concerned with practical issues than recommendations for those heads (though I would love to hear them). What do I need to know about different impedances? Are there basics about how they respond? For instance are there typical differences between running at 4 ohms and 16 ohms, or does it just depend on the setup? How is the output from the amp dispersed to multiple speakers? Since the 88 puts out a lot of wattage, what kind of speakers would I need to handle it? I see a lot of people who like 30 watt speakers. Would I need multiple speakers to spread out the output of the amp to avoid blowing speakers? I may not even be asking the right questions right now, but you have to start somewhere, and here I am. I may be asking for a two hour lecture to really answer the questions, but any tips or experiences that you feel would be prudent are much appreciated. Thanks for reading.

Hey man this post by Myles might help with the speaker impedance. I also agree with him that it matters very little.
drzamplifiers.proboards41.com/index.cgi?board=xperts&action=display&thread=1137175216&page=6#1144423437
If you are going to run a one speaker setup you will need a speaker capable of handling 90-100 watts of power if you are going to crank that Delta88. Something like the Celestion G12K-100 would do the trick. The Tonker or Swamp Thang from Eminence Speakers are very popular. They are rated at 150 watts power handling. If you are going to use the amps at lower volumes you can get away with using a less efficient speaker as well just don't crank the volume to high.
I much prefer a two speaker setup as opposed to one. I find the sound is less directional and is bigger as well. Personally I think with the amps you are interested in that the Z-Best 212 cabinet would be killer. The two speakers that are stock in a Z-Best is a Celestion Vintage 30 which is a 60 watt speaker and a G12H which is a 30 watt speaker, giving you about 90 watts of power handling. That more than enough to handle the 6545 or the Delta88. I love both these amps but considering that I as well will be getting a Delta soon, I hope you get the Delta! Hopefully Myles will chime in soon and give you a much more detailed explanation. He is the man. Hope this helps.

[myles]

billyguitar said:

Not that I'm an expert having only experimented one time, but here's what I noticed on my Bluesbreaker Reissue combo. It came with two eight ohm greenbacks wired for 16 ohms. Back when I used to gig that amp a lot I rewired it to 4 ohms for a while. It sort of tilted the frequency response lower, less highs and more lows. Actually very subtle. I rewired it back to 16 ohms. I've read either in Dave Funk's book or one of Gerald Weber's that at 16 ohms you are using the whole output transformer and at lesser impedance taps signal is only passing through that fractional amount of the transformer. i.e. 8 ohms would use 1/2 of the windings in the transformer. Who knows which sounds better? Might as well use the whole thing since we paid for it.

There is a lot of thinking on this subject but in the end I use the what I feel sounds best to me and that is totally subjective. Do what you like best.

[myles]

sae2111 said:

This is just a general amp question and I would be glad to hear from anyone more experienced than I....
To this point, I have only used combo amps. I will soon be purchasing either a 6545 or a Delta 88. I have never had to shop for a cabinet so I don't really know what I need. At the moment I'm more concerned with practical issues than recommendations for those heads (though I would love to hear them). What do I need to know about different impedences? Are there basics about how they respond? For instance are there typical differences between running at 4 ohms and 16 ohms, or does it just depend on the setup? How is the output from the amp dispersed to multiple speakers? Since the 88 puts out a lot of wattage, what kind of speakers would I need to handle it? I see a lot of people who like 30 watt speakers. Would I need multiple speakers to spread out the output of the amp to avoid blowing speakers? I may not even be asking the right questions right now, but you have to start somewhere, and here I am. I may be asking for a two hour lecture to really answer the questions, but any tips or experiences that you feel would be prudent are much appreciated. Thanks for reading.

Go hit my GAB website and go to the tube primer area and download my tube primer, the 200+ page two part one. That will answer a lot of questions.

[billyguitar]

I agree. The bottom line is use the tap that matches whatever speaker or cabinet you're using. It's all good. There isn't really a huge difference and in fact you may not hear a difference at all between the different taps.

[got twang?]

Myles:

First, I'd like to thank you for all the great advice/info you offer on the Z forum. I've learned so much, especially that I have so much more to learn.

I have two questions for you...

First, I have a MAZ 38 w/reverb that I purchased used (barely) in December. It was supposedly only used for 10-15 hours before I bought it, and by the looks of it - that's probably about right. I would like to replace all the tubes. My question is - what should I use for preamp & power tubes? I'm wanting to go toward the Marshally side of the spectrum with a fairly early breakup. I'm using this amp in a country/rock application.

Second, I went to practice tonight & when I powered up, I got absolutely no sound. No hiss, no hum - NOTHING! Do you have any ideas of what I could try to fix this? Maybe a rectifier tube?

Thank you in advance for your help here. I'm really under the gun as this I'm getting ready for my first gig with this amp in only 3 weeks, and I don't currently have a backup amp.

Thanks again,

Matt

[myles]

gottwang said:

Myles:

First, I'd like to thank you for all the great advice/info you offer on the Z forum. I've learned so much, especially that I have so much more to learn.

You are more than welcome

I have two questions for you...

First, I have a MAZ 38 w/reverb that I purchased used (barely) in December. It was supposedly only used for 10-15 hours before I bought it, and by the looks of it - that's probably about right. I would like to replace all the tubes. My question is - what should I use for preamp & power tubes? I'm wanting to go toward the Marshally side of the spectrum with a fairly early breakup. I'm using this amp in a country/rock application.

Tubes are really personal preference. In the output section I'd stick with the EL84S #5 or #6. In the phase inverter (V5) make sure there is either a 12AX7M or 12AX7R2 in there. They are the stock Z tubes and long plates with a nice current curve compare to shorter plate tubes. On V1 and V2, this is going to boil down to personal taste.

Second, I went to practice tonight & when I powered up, I got absolutely no sound. No hiss, no hum - NOTHING! Do you have any ideas of what I could try to fix this? Maybe a rectifier tube?

If the power light comes on but no sound comes out of the amp (make sure the speaker is plugged in) then it is most probably a bad rectifier.

Thank you in advance for your help here. I'm really under the gun as this I'm getting ready for my first gig with this amp in only 3 weeks, and I don't currently have a backup amp.

Thanks again,

Matt

You are more than welcome

[foxx]

Hi Myles, I have a problem with my Mazerati. I blew a 3A fuse. Next day I bought 2 replacement fuses from my Z Dealer. The amp fired up and touching the bare end of a cable made the usual noise so I though "it's fixed.
Now I have plugged in the guitar to play and "pop" the amp dies. Then I put in the other 3A fuse that I bought and the light stays on but the amp is dead quiet. No hiss no crackle no nothing. I just took it to Encore Music and drove home.
They plan on testing some tubes but no diagnosis has been made.
Do you have any ideas? Thanks for your time.

[myles]

foxx said:

Hi Myles, I have a problem with my Mazerati. I blew a 3A fuse. Next day I bought 2 replacement fuses from my Z Dealer. The amp fired up and touching the bare end of a cable made the usual noise so I though "it's fixed.
Now I have plugged in the guitar to play and "pop" the amp dies. Then I put in the other 3A fuse that I bought and the light stays on but the amp is dead quiet. No hiss no crackle no nothing. I just took it to Encore Music and drove home.
They plan on testing some tubes but no diagnosis has been made.
Do you have any ideas? Thanks for your time.

It sounds as if you have a bad rectifier.

If you replace the GZ34 / 5AR4 and it continues to happen then replace the output set as you may have a shorted output tube. But if the AC light comes on and there is no sound it is generally the rectifier.

[foxx]

Thanks Myles, it's at Encore Music right now, they haven't even looked at it yet. Tomorrow I will go there and "help" them fiqure it out. I could get it running for under $30. I just hope they have a 5AR4.

[myles]

foxx said:

Thanks Myles, it's at Encore Music right now, they haven't even looked at it yet. Tomorrow I will go there and "help" them fiqure it out. I could get it running for under $30. I just hope they have a 5AR4.

A new 5AR4 at straight retail is only about $25 and is a very common rectifier. If they charge you anything to pop in and try it I would be surprised as this takes about 5 seconds.

[foxx]

I just got off the phone with Steve at Encore. That is exactly what I had him do, and the amp is working and waiting for me. Thanks for your help Myles. They were going to send it to the shop, I called and suggested that it could be a bad rectifier so YOU JUST SAVED ME $$. Karma to ya Myles. THANKS

[foxx]

The Mazerati is working just fine, a $25 rectifier and I'm back in Dr Z fun TONE land. I've been playing thru my kid's 15 watt Brand X while without my rati and I was ready to cry. I played my acoustic instead.
I am soooooo glad to have my rati back, and to know it was just a bad tube. It has such a sweet, rich, 3D tone that I would have to better it before I could consider selling this amp. Thanks agin Myles

[John]

Now kick the wife and kids out the door with some money for Pizza Hut, and crank it up!!

I know what it's like when you've got a piece of gear that isn't working right, and you're upset because you don't know how much it's going to cost to fix it...and...and...and.

But when you get it back, ESPECIALLY when it's something small or low cost, you feel so good. Have fun jamming!

[myles]

foxx said:

I just got off the phone with Steve at Encore. That is exactly what I had him do, and the amp is working and waiting for me. Thanks for your help Myles. They were going to send it to the shop, I called and suggested that it could be a bad rectifier so YOU JUST SAVED ME $$. Karma to ya Myles. THANKS

You are more than welcome. There is not a lot that can go wrong with your amp short of tubes wearing out. Normally, rectifiers go for decades without any problems but occasionally you do get one that goes south from just plain knocking about or because it was not great at the get go.

About 5 years ago I was doing a lot of stuff with Bad Cat amps and 50% of them that came out of the shipping box would blow the fuse when taken out of standby. In every case it was bad rectifiers and they were all Chinese ones at the time from Sino. Sino is sort of a Chinese co-op of lots of little tube factories. Shuguang is the big gun in China and their stuff is much more reliable than Sino stuff.

In any case ... get some NOS (any of them) GZ34 / 5AR4 from Mike at KCA and never worry about rectifier issues again.

[prowler]

Myles...

I'd like to try some NOS tubes in my SRZ-65. I want a thick articulate rock tone. What are your recommendations for V1, V2 & V3?

[myles]

prowler said:

Myles...

I'd like to try some NOS tubes in my SRZ-65. I want a thick articulate rock tone. What are your recommendations for V1, V2 & V3?

V1 and V2 is all you have to change if you have a good matched long plate phase inverter in V3.

And .... V1 is most of this.

Try an NOS RFT and those Svetlanas that the Doc is using in some of his amps now are pretty nice too.

[tjstrat]

I bought a used Studio Lead a few months back and have been experiencing a hissing, popping, and crackling sound that rises in intensity and then stops and then begins all over. It's random and not cyclical, so I figure it may be time to replace the preamp tubes.

The current set is V1 and V2 12AX7, V3 12AT7, V4 5751, and a 12AX7LPS in V5. I have a fairly good old RCA for V1 and a JJ ECC83 for V2. Can I use another 12AX7 for V4 and is there a good JJ equal for the LPS for V5?

Thanks!

[myles]

tjstrat said:

I bought a used Studio Lead a few months back and have been experiencing a hissing, popping, and crackling sound that rises in intensity and then stops and then begins all over. It's random and not cyclical, so I figure it may be time to replace the preamp tubes.

The current set is V1 and V2 12AX7, V3 12AT7, V4 5751, and a 12AX7LPS in V5. I have a fairly good old RCA for V1 and a JJ ECC83 for V2. Can I use another 12AX7 for V4 and is there a good JJ equal for the LPS for V5?

Thanks!

I think I already got to this via your email.

On V5, I use 12AX7M MPIs at

www.groovetubes.com/product.cfm?Product_ID=1723



The new JJ 803S may work nicely but I have not tested enough of them yet to get stable standing current curves. But these may be a winner too.

On the LPS ... you need to check that is has at least 1.1 milliamps or current output on each side.

[jessterr]

Myles,

First, thanks very much for your generous support here on the board. I know it takes a great deal of your time, and we all appreciate it immensely!

I need some advice. I have a small mountain of NOS and lightly used EL84s that I bought on eBay before I knew any better. Now that I'm a bit more educated about tubes from mentors like yourself and Mike at KCA, I won't be doing that any more, but I just purchased a Weber bias-rite and am working through the process of identifying matched pairs in my Maz 18. I've been able to come up with quite a few of them actually, within 1 ma of each other, but now I'm starting to hit the wall. How closely would you advise that a pair of EL 84's should be matched to provide good performance? I've been shooting for 1 ma, but is that too critical? I was actually quite surprised to find that the original set of Sovteks that came with the amp, which was purchased new and has only seen very light use, had a spread of about 10 ma!

On a closely related subject, I owe you thanks already because, based on your advice, I ordered a set of GT EL-84S's at #6, which I received about a week ago. I measured them on the Bias-Rite, and they were 44.1 ma and 44.1 ma! Incredible. I'm now a Groove Tubes convert.

Thanks very much,
Jesse

[abradpaisleyfan]

Hey myles hows it going. got a question. got a vox ac30 custom classic and was wondering what you would recommend to put in it as far as valves go. groove tubes for sure. let me know what you would advise

[guitarman1]

Hello Myles and Chad. I just bought a RX ES and was wondering about EF86 recommendations. It currently has a Dario. How would you compare the NOS GEC & Mullard at KCA to the Dario please?

Thanks,

Steve

[myles]

abradpaisleyfan said:

Hey myles hows it going. got a question. got a vox ac30 custom classic and was wondering what you would recommend to put in it as far as valves go. groove tubes for sure. let me know what you would advise

No to steer away GT business but from my point of view I like to recommend what from my point of view is the "right tool for the job".

In the case of the AC30CC ..... the first tube in these amps is not worked very hard (which has nothing to do with great tone but the V1 in this amp will last for decades).

I have played with a lot of these amps at this point and there are a few I have found to be pretty spectacular, articulate and not too bright in an amp that can be a bright amp.

One is this:



kcanostubes.com/content/estore_details.asp?category=&product=14


.............


The other is this one:



kcanostubes.com/content/estore_details.asp?category=&product=31


....................


These are both from Mike at www.kcanostubes.com


The Brimar may be more pricy but it is also probably the last V1 tube you will ever need in the AC30CC.

The GT ECC83S is in the same ballpark in some ways but has more of a midrange bump that is not in the other two tubes. The other two are s m o o o o o o o t h

The AC30CC had very nice EQ that really loves the RFT and Brimar.

Guess I missed a sale

[myles]

Jesse ... see below ...

jessterr said:

Myles,

First, thanks very much for your generous support here on the board. I know it takes a great deal of your time, and we all appreciate it immensely!

You are very welcome


I need some advice. I have a small mountain of NOS and lightly used EL84s that I bought on eBay before I knew any better. Now that I'm a bit more educated about tubes from mentors like yourself and Mike at KCA, I won't be doing that any more, but I just purchased a Weber bias-rite and am working through the process of identifying matched pairs in my Maz 18. I've been able to come up with quite a few of them actually, within 1 ma of each other, but now I'm starting to hit the wall. How closely would you advise that a pair of EL 84's should be matched to provide good performance? I've been shooting for 1 ma, but is that too critical? I was actually quite surprised to find that the original set of Sovteks that came with the amp, which was purchased new and has only seen very light use, had a spread of about 10 ma!

You are measuring static rather than dynamic dissapation but that is ok for the most part but is not the best benchmark. Then again ... to test dynamically takes about $400,000 of test stuff so the static method is what most folks use.

In any case ... 10% is a really nice static match. So ... you may have some nice matched pairs after all.

The Sovteks .... toss them.

On a closely related subject, I owe you thanks already because, based on your advice, I ordered a set of GT EL-84S's at #6, which I received about a week ago. I measured them on the Bias-Rite, and they were 44.1 ma and 44.1 ma! Incredible. I'm now a Groove Tubes convert.

On the GT stuff with that tight of a match ... it was a bit of luck. GT stuff can have a static mismatch of 10% as a general rule but if you ever want to drop by the factory (same offer to all on this forum) and bring your "matched tubes" I will be happy to show you a little test procedure.

I will take the "matched set" and put them on a curve tracer. Nine times out of ten the traces will not line up. It will look like two different tubes. I will then let you pull any GT set from stock and run the same test.

Think if static idle dissapation this way. I drive a Scion with a 1500cc engine and 105 horsepower. It idles at about 700 rpm. I have a friend with a BMW M-5. It has the same idle. I guess by some folk's thinking the two cars are matched.

Thanks very much,
Jesse

[myles]

guitarman1 said:

Hello Myles and Chad. I just bought a RX ES and was wondering about EF86 recommendations. It currently has a Dario. How would you compare the NOS GEC & Mullard at KCA to the Dario please?

Thanks,

Steve

Steve,

I will hope Chad pipes in here but I find the Mullard and GEC to be a bit smoother. Better? Not yes or no here but different.

But Chad listens to a bank of EF86 amps many nights a week and can tell you what he thinks, what Brad Paisley thinks, and what Gary Hooker think. I'd get his take on it.

[prowler]

myles said:

Try an NOS RFT and those Svetlanas that the Doc is using in some of his amps now are pretty nice too.

Myles,

I got a NOS RFT from Mike @ KCA. You were 1000% correct. The RFT tube is exactly what I wanted. I really like the Svets that Z put in my SRZ but this RFT really nails the tone I was after. Much smoother & more beefy across the entire range. Thanks for the tip. This tube is perfect.

[myles]

prowler said:

myles said:

Try an NOS RFT and those Svetlanas that the Doc is using in some of his amps now are pretty nice too.

Myles,

I got a NOS RFT from Mike @ KCA. You were 1000% correct. The RFT tube is exactly what I wanted. I really like the Svets that Z put in my SRZ but this RFT really nails the tone I was after. Much smoother & more beefy across the entire range. Thanks for the tip. This tube is perfect.

Unfortunately, the RFT's would be too pricy and hard to get in quantity for amp production but ... if it is for your own personal amp then it's much easier to accomplish.

Very cool in the SRZ and 6545.

[jwr]

Myles I just read here on the forum that the Rx ES is out of phase with other amps. Is this true? I would think the speakers would be wired out of phase, not the amp. Just curious because I'm thinking of buying one and plan to use it with my 38 SR and Z-28. As always thanks for your time.
Jason

[phooey]

we really like the dario ef86. i've set up the stingray in just about every situation you can think of so far and it sounds wonderful. wish you guys coulda heard it at leno the other night