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Post by pintail78 on Nov 10, 2011 18:25:02 GMT -7
I have a KT-45 with GT 34L's in it, what are the tubes options for it: EL-34, 6AC7, 6L6, KT77, KT66, maybe even 6550? Rectifier SS, GZ34, 5V4, 5UG etc......Of course with a rebias for all.
Seems like lots of options here. I mainly play blues, I like a thicker tone and breakup. Whats a good combo to try, I was thinking KT-66/6AC7 and maybe 5U4/5V4 rectifier??? Thanks as always. JT.
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Post by highwayman (Dave) on Nov 10, 2011 20:00:41 GMT -7
Myles,
Thanks for all of your expertise and sharing here with us. I've read all of the questions and pages just to learn what I can about how these amps really work. While I don't possess the electrical knowledge that some members obviously do, I still appreciate the details and the folks like yourself that have figured it out.
Here's a question I'm sure someone has asked before, but I was wondering if your perspective may have changed any... with all of the quality/reliability/spec issues that seem to plague most tube users and the ever dwindling supply of NOS tubes (that Doc hasn't already rejected ;D), why hasn't a reputable "boutique" US or Canadian tube manufacturer sprouted up somewhere? I can imagine that making the tubes is no simple matter in itself, let alone building to higher specs, etc., but it would seem that there might be enough demand to support such a venture. Given the Doc's success in building/selling all of these fine amps over the years (not to mention the hoards of Fenders, Marshalls,Vox, etc, out there) there must be some demand vacuum (pun intended) to be filled. Any current thoughts or observations on this?
Best regards,
Dave
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Post by Deleted on Nov 10, 2011 20:36:02 GMT -7
Dave - I think Myles would be the perfect candidate to run such a venture. Sadly I don't think we will see that anytime soon. Wish I had the 8 million dollars or so to get something like that off the ground.
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Post by Eddie on Nov 10, 2011 22:48:26 GMT -7
Myles, Thanks for all of your expertise and sharing here with us. I've read all of the questions and pages just to learn what I can about how these amps really work. While I don't possess the electrical knowledge that some members obviously do, I still appreciate the details and the folks like yourself that have figured it out. Here's a question I'm sure someone has asked before, but I was wondering if your perspective may have changed any... with all of the quality/reliability/spec issues that seem to plague most tube users and the ever dwindling supply of NOS tubes (that Doc hasn't already rejected ;D), why hasn't a reputable "boutique" US or Canadian tube manufacturer sprouted up somewhere? I can imagine that making the tubes is no simple matter in itself, let alone building to higher specs, etc., but it would seem that there might be enough demand to support such a venture. Given the Doc's success in building/selling all of these fine amps over the years (not to mention the hoards of Fenders, Marshalls,Vox, etc, out there) there must be some demand vacuum (pun intended) to be filled. Any current thoughts or observations on this? Best regards, Dave I'd love to see it but I think three letters keep it from happening: E. P. A. Eddie |
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Post by myles on Nov 11, 2011 11:22:07 GMT -7
I have a KT-45 with GT 34L's in it, what are the tubes options for it: EL-34, 6AC7, 6L6, KT77, KT66, maybe even 6550? Rectifier SS, GZ34, 5V4, 5UG etc......Of course with a rebias for all. Seems like lots of options here. I mainly play blues, I like a thicker tone and breakup. Whats a good combo to try, I was thinking KT-66/6AC7 and maybe 5U4/5V4 rectifier??? Thanks as always. JT. The output transformer is optimized for EL34 / 6CA7 / KT77 A KT66 is a very different tube, in the 6L6 family. 6550s sound terrible when pushed into distortion. |
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Post by myles on Nov 11, 2011 11:25:53 GMT -7
Making tubes has nothing to do with the EPA even in California. That was an excuse used by somebody that attempted to make tubes here but when the cost kept rising and the expertise was not cheap enough the EPA logic came into play. I initially even bought it until I researched the subject with the EPA myself.
Tubes could be made in the USA, it is a matter of initial funding. How much? Your guess is as good as mine. It would be much less expensive than a group of programmers developing the next big selling video game that can have years of development.
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Post by electricflag on Nov 11, 2011 14:33:29 GMT -7
Myles,
Interesting point. At least you and Groove Tubes once put forth an effort to produce a better product. Everyone complains about current tubes, but you "walked the walk and talked the talked.
There is a silent nation of us out here that truley appreciate your struggles in the tubes industries. You are a true hero in our eyes.
-Rick
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Post by myles on Nov 12, 2011 11:13:43 GMT -7
Myles, Interesting point. At least you and Groove Tubes once put forth an effort to produce a better product. Everyone complains about current tubes, but you "walked the walk and talked the talked. There is a silent nation of us out here that truley appreciate your struggles in the tubes industries. You are a true hero in our eyes. -Rick Rick, Here is a link to a page on my GAB website that has a few photos when this was in process. If you click on most of the shots they will enlarge. www.guitaramplifierblueprinting.com/gttubes.html |
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Post by electricflag on Nov 14, 2011 7:48:51 GMT -7
Myles,
The Kentucy Radio tooling! What excellent products came form it. Groove-Tubes, G.E. silver plates, Ken-Rad black plates.
-Rick
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Post by jesslm02 on Nov 14, 2011 8:12:40 GMT -7
I currently have an RX JR. I love the amp and the tone that I get from it. After speaking with Brent I decided to put in an 5AR4 to tighten up the low end a bit. It done great through several practices and a gig. The next practice I could tell the amp started to sound a little different, I didn't know what but I could definitely tell. It got really bright in the mix at practice and almost sounded 'sterile' or brittle (for lack of a better word) in the treble. I had the treble turned down already on 2 I believe. I turned the treble up and it added too much and got really ice-picky but still brittle sounding. If I turn the treble down it looses all treble and gets really muddy. It's almost like it lost the chime. There is almost no 'harmonic content' so to speak in the treble frequencies. This thing normally sounds pretty thick and punchy even with the TE-50 Telecaster pickup I have in my guitar, with tons of harmonics.
Speaker cab is a 2x12 with a Blue and H30 at 4 ohms.
I bypassed all my pedals and went straight in with a cord. No change.
I tried a different cord. No change.
I put the 5Y3 back in. Not any better.
I am thinking this is most likely a tube issue. Any thoughts? Suggestions?
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Post by myles on Nov 14, 2011 9:45:18 GMT -7
I currently have an RX JR. I love the amp and the tone that I get from it. After speaking with Brent I decided to put in an 5AR4 to tighten up the low end a bit. It done great through several practices and a gig. The next practice I could tell the amp started to sound a little different, I didn't know what but I could definitely tell. It got really bright in the mix at practice and almost sounded 'sterile' or brittle (for lack of a better word) in the treble. I had the treble turned down already on 2 I believe. I turned the treble up and it added too much and got really ice-picky but still brittle sounding. If I turn the treble down it looses all treble and gets really muddy. It's almost like it lost the chime. There is almost no 'harmonic content' so to speak in the treble frequencies. This thing normally sounds pretty thick and punchy even with the TE-50 Telecaster pickup I have in my guitar, with tons of harmonics. Speaker cab is a 2x12 with a Blue and H30 at 4 ohms. I bypassed all my pedals and went straight in with a cord. No change. I tried a different cord. No change. I put the 5Y3 back in. Not any better. I am thinking this is most likely a tube issue. Any thoughts? Suggestions? If the only thing you did was go from a 5Y3 to a 5AR4 you raised your voltages across the entire circuit. Put things back. Did things go back to how they were before? If not, you probably do have a tube issue, something changed. Something else could have changed as well such as a cap or resistor or .... |
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Post by headshrinker (Marc) on Nov 14, 2011 9:59:15 GMT -7
jesslm02: Not to hijack Myles thread. I recently had a similar thing happen with my Rxjr. As the night went on the amp got brighter and brighter but not in a good way. I changed out the jj power tubes that were in it , that weren't that old, and the problem went away. I've noticed when the current jjs start to go they seem to get bright and thin with sunken mids.
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Post by myles on Nov 14, 2011 12:58:10 GMT -7
jesslm02: Not to hijack Myles thread. I recently had a similar thing happen with my Rxjr. As the night went on the amp got brighter and brighter but not in a good way. I changed out the jj power tubes that were in it , that weren't that old, and the problem went away. I've noticed when the current jjs start to go they seem to get bright and thin with sunken mids. Marc, Thanks for the hijack. Very good info. Feel free to hijack any thread of mine anytime if you have thoughts or ideas that could help. More heads are better than one  |
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Post by jesslm02 on Nov 14, 2011 13:09:43 GMT -7
That seems to be my issue. It got really bright and the mid control didn't help much.
And Miles, thanks for your suggestion as well. I put the 5y3 back in but it did the same. And you are right about it could be a cap or resistor, so if new tubes don't solve it I may send it to Z for a check-up. It is about 4 years old so it might be good to have checked out anyways.
Thanks for the help folks!
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Post by myles on Nov 14, 2011 13:13:32 GMT -7
That seems to be my issue. It got really bright and the mid control didn't help much. And Miles, thanks for your suggestion as well. I put the 5y3 back in but it did the same. And you are right about it could be a cap or resistor, so if new tubes don't solve it I may send it to Z for a check-up. It is about 4 years old so it might be good to have checked out anyways. Thanks for the help folks! Good luck and happy playing! |
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Post by Scott on Nov 22, 2011 2:20:40 GMT -7
Myles, I would love to know your opinion in these (Current production) 7189 tubes: The Preferred Series 7189 (Premium EL84): thetubestore.com/preferred7189.html2 of the Jr. boys seem to like them so far, but further testing is still going on. |
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Post by myles on Nov 22, 2011 12:17:04 GMT -7
Myles, I would love to know your opinion in these (Current production) 7189 tubes: The Preferred Series 7189 (Premium EL84): thetubestore.com/preferred7189.html2 of the Jr. boys seem to like them so far, but further testing is still going on. If your folks testing them compare them to the common Sovtek EL84M heavy duty EL84 they might 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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Post by Scott on Nov 22, 2011 17:26:47 GMT -7
Thanks so much!
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Post by Martanthegreat on Nov 30, 2011 11:40:00 GMT -7
Myles,
Amp gets a low hum after playing awhile. I push down on one of the pre amps tubes and it stops. im guessing the tube is Bad? The amp has 3 nos 6SL7GT's, do replacements need to be matched? Which are the best Nos ones to get. I believe I have 2 nos RCA and a Nos tung-sol brown base. cant read the markings on the tubes. thanks Martin
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Post by myles on Dec 1, 2011 9:55:38 GMT -7
Myles, Amp gets a low hum after playing awhile. I push down on one of the pre amps tubes and it stops. im guessing the tube is Bad? The amp has 3 nos 6SL7GT's, do replacements need to be matched? Which are the best Nos ones to get. I believe I have 2 nos RCA and a Nos tung-sol brown base. cant read the markings on the tubes. thanks Martin Sounds like a bad tube, microphonic. Common in those bigger bottle preamp tubes. No special selection needed other than proper testing. Check with Rob Hull at www.tubedepot.com or Mike at www.kcanostubes.com for replacements. |
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Post by Scott on Dec 3, 2011 11:27:32 GMT -7
Myles, If you were going to buy some NOS Phase Inverter tubes for our cathode biased, EL-84 Maz Jr, what would be some of your top selections, and maybe a short why. My understanding is a 12AX7 would not be your first choice. As always, thanks! |
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Post by myles on Dec 4, 2011 11:38:48 GMT -7
Myles, If you were going to buy some NOS Phase Inverter tubes for our cathode biased, EL-84 Maz Jr, what would be some of your top selections, and maybe a short why. My understanding is a 12AX7 would not be your first choice. As always, thanks! Scott, This is totally personal taste and preference with countless options. I have written volumes on this subject and there is a lot on my GAB website. I generally prefer long plate tubes in the PI slot (my personal general taste much of the time but not all the time). I do not select phase inverters for gain. I select them by their plate current which has to be in a proper range (1.2mA / 12AX7 as an example). 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. 12AX7 vs 5751 vs 12AT7 etc. .... a matter of design and personal taste. For a 12AX7 you can't go wrong with RCA, GE, Brimar, Mullard as just a few examples. |
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Post by Scott on Dec 4, 2011 12:03:08 GMT -7
A good honest answer... Thank you sir! |
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Post by Andy 67 on Dec 13, 2011 16:47:03 GMT -7
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Post by internetuser on Dec 17, 2011 4:15:31 GMT -7
Myles, how would you compare the KT45 to the Victoria Sovereign, they seem very similair on paper.
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Post by Deleted on Dec 17, 2011 13:55:56 GMT -7
Myles, how would you compare the KT45 to the Victoria Sovereign, they seem very similair on paper. There Sovereign is a high gain amp. The KT-45 is not. Here is some info from Myles on the Sovereign. www.guitaramplifierblueprinting.com/Sovereign.pdf |
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Post by doctorice on Dec 22, 2011 15:15:27 GMT -7
Hi Myles,
I just picked up a 6545 built in 2002. It has GT "6" rated EL34s in it. They're in OK shape, but it's time for a new set. I'm not clear on which version of the EL34 I should be looking at for this amp; I understand there are 25-watt and 30-watt alternatives.
As always any recommendation on particular brands to seek out or avoid would be most welcome. I'd consider buying a regular pair and / or a NOS set.
Thanks in advance.
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Post by randalp3000 on Dec 22, 2011 15:38:20 GMT -7
On the Z site it appears Doc is using the JJ E34L's in the KT and the SRZ. I believe those are both 25 watt tubes. The GT EL34's are 25 watt and the GT E34L's are 30 watt.
Hope this helps a little. Looking forward to Myles' suggestion also
rp
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Post by Albert on Dec 23, 2011 21:18:21 GMT -7
Hi Myles, Just put in some Jan Phillips 6v6gt tubes in my Remedy and got this ...  Here is the voltage..  And the current...  Is this normal for NOS 6v6 I thought I read somewhere that they will stripe a little the total wattage comes out to be P=IE .068*339=23watts divided by 2 tubes =11.5 watts so not to worried there so my question would be is this normal or should I pull the tubes and send them back Thanks Merry Christmas Albert |
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Post by fishman on Dec 24, 2011 16:09:03 GMT -7
"This my dear Holmes, is a mystery of the highest order"
Geordie to Data
I am way confused..HA...nothing new there.....
my plate voltage approx 360-365 old wiring for sure, I am sure the actual power flunctuates that much or more...68-70ma on current....
thanks for point on fixed bias...
so, right now, I have pretty much no clue, seems to me if that were actually correct the tubes would melt considering they are over 100% at that level....
I am soooo confused......HA
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