[Sound Trooper]

wow thanks for introducing me to the community @UntilThen. really appreciate it as the first steps are always the hardest . Will take me awhile to digest all the information available in this thread. Something to think about until glenn can start on the amp.

Before getting something, i usually like to research deeply and know what i am getting into before committing. think maybe it has something to do with my engineering background? However, this tube thing is really beyond me with all the many different tubes and its purposes. So apologies to all in advance if i come across as relentless or excessively pertinacious.

@L0rdGwyn and @UntilThen I think glenn has mentioned that he is using 2 x 6j5 instead of one 6ns7 as well. In fact, he mentioned that he is using the gec l63 that you recommended as well. can anybody enlighten me on the pros and cons between the two? i know 6j5 is just half of a 6ns7 so any difference might be tubes cost or longevity? on another similar note, is 6 x 6bx7 and 2 x 6as7g power tubes different in terms of sonics?

From my limited research, an extremely simplified demonstration of the otl amp is as follows: power from the socket goes into the transformer, ac rectified by rectifier stage to become dc, signal 'prepared' or preamped by driver tubes and then amplified and changed into ac by power tubes? Therefore, there are usually three classes of tubes, mainly rectifier, driver (preamp or input) and power (output). Please correct me if i am wrong.

Hey there, to play the devil’s advocate. Get a GEL3N and forget about all the tube rolling “madness”.

 

[JazzVinyl]

In @UntilThen 's suggested setup for @Ramenik he only included 6J5 sockets, no 6SN7.

Glenn's configuration is vastly more versatile. No shame in using Deyan's adapter for 6/12J5 in the SN7 socket.
Need the pin 1 to attach to ground? Easy to do without surgery

I like your amp LG, but I would not completely discount C3g, used with you Japanese 6AS7G or 5998's is a worthy roll, imho

Cheers...

 

[JazzVinyl]

Hey there, to play the devil’s advocate. Get a GEL3N and forget about all the tube rolling “madness”.

Madness to some, fun and rewarding to most

 

[L0rdGwyn]

I like your amp LG, but I would not completely discount C3g, used with you Japanese 6AS7G or 5998's is a worthy roll, imho

I have never discounted them! A 6J5-only setup was not my idea, it was UT's. The C3g is an excellent tube, and I was also disappointed I had not spent more time with the EL32 while listening before removing the sockets. I may even keep a pair of C3g and use adapters for the 6J5 sockets. I only made the change because I prefer the 6J5 overall, but there are so many great tubes for the GOTL, you cannot go wrong with any setup.

 

[GDuss]

I have never discounted them! A 6J5-only setup was not my idea, it was UT's. The C3g is an excellent tube, and I was also disappointed I had not spent more time with the EL32 while listening before removing the sockets. I may even keep a pair of C3g and use adapters for the 6J5 sockets. I only made the change because I prefer the 6J5 overall, but there are so many great tubes for the GOTL, you cannot go wrong with any setup.

A couple of questions related to this discussion. First, I think your surgery converted the two C3g sockets to two 6J5 correct? But did you still leave the single 6SN7 slot? Or did that get converted to something else?

Second, if one were to use a dual 6J5 to 6SN7 adapter, with nothing in the C3g slots, would that be equivalent to you using two 6J5s in your new slots and nothing in the 6SN7 slot? Or are the 6J5 tubes biased differently in your new slots, which makes them better (or at least different) than using the adapter in the 6SN7 slot?

I have no plans to copy your surgery, just curious as to how your new setup compares to the old one.

 

[L0rdGwyn]

A couple of questions related to this discussion. First, I think your surgery converted the two C3g sockets to two 6J5 correct? But did you still leave the single 6SN7 slot? Or did that get converted to something else?

Second, if one were to use a dual 6J5 to 6SN7 adapter, with nothing in the C3g slots, would that be equivalent to you using two 6J5s in your new slots and nothing in the 6SN7 slot? Or are the 6J5 tubes biased differently in your new slots, which makes them better (or at least different) than using the adapter in the 6SN7 slot?

I have no plans to copy your surgery, just curious as to how your new setup compares to the old one.

Yes, two C3g sockets converted to 6J5 sockets. The single 6SN7 socket remains, which I mostly use for ECC32 and 6N7. The filament pins of the 6SN7 socket are now connected to the filament pins of the 6J5, so the 6/12/25V switch affects all three sockets.

Using the 6J5 adapter in the 6SN7 slot is equivalent to using 6J5 specific sockets since the 6SN7 and 6J5 use the same cathode bias resistor. The only caveat is pin 1 of the 6J5 sockets is grounded. Many 6J5/6C5/6P5 tubes have metal internal or external shields tied to pin 1, so grounding that pin protects the tube from extraneous RFI. It is not a necessity and you could have an adapter made to tie pin 1 to the cathode, which would also ground it. Not sure if that is built into the Chinese adapters or not.

 

[JazzVinyl]

I have never discounted them! A 6J5-only setup was not my idea, it was UT's. The C3g is an excellent tube, and I was also disappointed I had not spent more time with the EL32 while listening before removing the sockets. I may even keep a pair of C3g and use adapters for the 6J5 sockets. I only made the change because I prefer the 6J5 overall, but there are so many great tubes for the GOTL, you cannot go wrong with any setup.

Gotcha, I thought removing the C3g sockets meant no more C3g for you as you might have also re-biased for 6J5.

And agree, about "cannot go wrong" with a Glenn

 

[GDuss]

Yes, two C3g sockets converted to 6J5 sockets. The single 6SN7 socket remains, which I mostly use for ECC32 and 6N7. The filament pins of the 6SN7 socket are now connected to the filament pins of the 6J5, so the 6/12/25V switch affects all three sockets.

Using the 6J5 adapter in the 6SN7 slot is equivalent to using 6J5 specific sockets since the 6SN7 and 6J5 use the same cathode bias resistor. The only caveat is pin 1 of the 6J5 sockets is grounded. Many 6J5/6C5/6P5 tubes have metal internal or external shields tied to pin 1, so grounding that pin protects the tube from extraneous RFI. It is not a necessity and you could have an adapter made to tie pin 1 to the cathode, which would also ground it. Not sure if that is built into the Chinese adapters or not.

Thanks for the details. I didn't know about the 6/12/25V switch change you did also. Your bravery continues to be revealed.

And now you could get completely ridiculous and put two 6J5 in your new sockets and then run two more 6J5 in the 6SN7 slot with a dual adapter . Double the 6J5 love.

 

[L0rdGwyn]

Gotcha, I thought removing the C3g sockets meant no more C3g for you as you might have also re-biased for 6J5.

And agree, about "cannot go wrong" with a Glenn

They have been re-biased, but I think the C3g could still sound great with adapters, we will see!

Thanks for the details. I didn't know about the 6/12/25V switch change you did also. Your bravery continues to be revealed.

And now you could get completely ridiculous and put two 6J5 in your new sockets and then run two more 6J5 in the 6SN7 slot with a dual adapter . Double the 6J5 love.

Wow a quad 6J5 setup, not sure what that would do for the sound of the amp, I am a little afraid to find out.

 

[JazzVinyl]

They have been re-biased, but I think the C3g could still sound great with adapters, we will see!

Bang up job you did, LG!! Congrats again!

 

[UntilThen]

Holy moly, I woke up today to find the thread has become a United Nations.

 

[UntilThen]

wow thanks for introducing me to the community @UntilThen. really appreciate it as the first steps are always the hardest . Will take me awhile to digest all the information available in this thread. Something to think about until glenn can start on the amp.

Before getting something, i usually like to research deeply and know what i am getting into before committing. think maybe it has something to do with my engineering background? However, this tube thing is really beyond me with all the many different tubes and its purposes. So apologies to all in advance if i come across as relentless or excessively pertinacious.

@L0rdGwyn and @UntilThen I think glenn has mentioned that he is using 2 x 6j5 instead of one 6ns7 as well. In fact, he mentioned that he is using the gec l63 that you recommended as well. can anybody enlighten me on the pros and cons between the two? i know 6j5 is just half of a 6ns7 so any difference might be tubes cost or longevity? on another similar note, is 6 x 6bx7 and 2 x 6as7g power tubes different in terms of sonics?

From my limited research, an extremely simplified demonstration of the otl amp is as follows: power from the socket goes into the transformer, ac rectified by rectifier stage to become dc, signal 'prepared' or preamped by driver tubes and then amplified and changed into ac by power tubes? Therefore, there are usually three classes of tubes, mainly rectifier, driver (preamp or input) and power (output). Please correct me if i am wrong.

My pleasure Nik. What you didn't tell me was that you're an engineer. I would have suggested something more Frankenstein ... ish. The reason for my suggestion is because you said it's rather bewildering with all the different tubes and sockets configuration. So I thought I'll take out the c3g socket, stick in the dual 6J5 socket and for a bit of pure poetry and looks, add in a tube rectifier which is also great in sound and not just looks - the rectifier I mean.

So here are many other variations ( now you won't be confused because you're an engineer and engineers loves choices !!! ) :-

B choice) - This is my GOTL.
Configuration:-

• 6 x 6BL7 or 2 / 4 x 6as7 or 2 x 6336 as power tubes
• 2 x c3g or one 6SN7 for either 6, 12 or 25 volts 6SN7
• 6.3 or 12.6 or 25.2 volts switch
• Hexfred rectifier
• 5998 boost switch. - I have this
• Lundahl transformer
• Russian caps
• Gold Point 47 steps attenuator

C choice or Sophie's choice or @L0rdGwyn 's choice
Configuration:-

• 6 x 6BL7 or 2 / 4 x 6as7 or 2 x 6336 as power tubes
• 2 x L63 / 6J5 / 6C5 / 12J5 - switchable between 6J5 or 12J5
• one 6SN7 for 6, 12, 25 volts 6SN7
• 6.3 or 12.6 or 25.2 volts switch
  
• Lundahl transformer
• Jupiters caps
• Gold Point 47 steps attenuator

D choice or @Sound Trooper 's and @whirlwind's choice (he's your countryman too)
An OTC amp using EL3N tubes - EL3N driving EL3N. Very pretty and good looking amp - simple and no tube rolling.


E choice - @leftside and @TonyNewman 's choice :-
Glenn 300b amp


F choice - @UntilThen next amp from Glenn choice :-
Berlin - similar to EL3N amp but using Telefunken EL11 and EL12 spez tubes. But trust me these grey dignified tubes looks better than the red 'driving Miss Daisy' EL3N tubes !


G choice - @DecentLevi 's El Darwin :-
6SN7 and dual 6J5 using KT66, EL34, EL38, EL39, 6L6, 5881, EL12 spez, KT77, 6V6 power tubes. This one is about evolution. But very flexible.


H choice - @leftside 's orginal idea (he's got patent on this)
L63 / 6J5 / 6C5 with EL34 or KT66 power tubes

Some of us will copy Leftside soon because who cares about patents !!!
So I'll have 'Sydney' in a year's time that is similar to Lefty's patent. @whirlwind having something similar too. DecentLevi's choice is based on this too.


I choice - deary me I forgot @Xcalibur255 's choice - there's only one in the world.
OTC based on 45 tubes !!!

 

[UntilThen]

Lastly Nik, you can buy my Sansui that is made of pure gold and weigh 32 kgs. It's fully balanced solid state !!! Tubeless and more sexy trust me. The sound is pure classic Sansui - made in the Golden Age of Audio.

 

[UntilThen]

All quiet on the Western front here. What happened?

 

[L0rdGwyn]

(....continues listening to GOTL in placid silence....)