Tube Amp Archive

OK, thank you!

Thanks sluckey - Gotcha on all. Another question - I have attempted to approximate the voltage gain of circuit but not certain. Might I ask you if you feel this circuit is going to supply more or less power in the secondary of reverb transformer as the standard Fender parallel 12AT7 with 2.2K Rk ful...

Hello- I am wanting to try a push-pull reverb driver using center tapped transformer in a build to replace the parallel 12AT7 reverb driver. The intent is to have a clean tank driver and by using push-pull core saturation is of less problems. In past I used the Edcor reverb driver transformer with p...

Thought I would post this for info, a learning experience for me - After a couple of days of testing/use the "Gain" pot R-14 got mildly scratchy when turning. Removed the LNF capacitor C-9 and scratchiness went away. I had originally installed a NOS Orange Drop 6PS 0.047 @ 600v cap for C-9. I replac...

Thanks Stevem- Never have experimented with that but thank you for the info. Will see. I like that bias circuit because if I have a pot wiper connection go open, or even a pot track itself, the bias will rise to its peak value and not lose its path to tube grids. Am excited about this Wonderland cir...

Just finished "Wonderland" build based on the info from The Tone Geek's "Fairfield County Signature" version. Built on Super Reverb chassis, 290-EX power, 2x6L6GC to an O/Netics A-431 output (not using UL), Edcor 5 watt 7K reverb driver, mil surplus sealed 8H choke. Subbed a 6K6GT for reverb driver....

Thank you lonote-
That is a good suggestion. The original circuit of Wonderland used a 100K dwell pot. In some builds a 250K dwell pot was used to try and increase the dwell. I believe I will try this.
Thank you

I just finished a 50 watt "Wonderland" build based on the information on The Tone Geek's site for the "Fairfield County Signature". Mine is point to point on SR size chassis. The amp is working fine except for the reverb drive to the 8 ohm tank. During my study on this amp I read a number of comment...

Hello- In reference to the attached schematic I wanted to ask others for any commentary in regards to the mixer tube V-4. I am curious about the configuration of the components R-42, R-27 and C-22 in the plate circuits of V-4A,B. It appears as a form of "common anode mixer" to me since there is a DC...

Thank you very much for the explanation and help here.

Thanks all for helpful replies.

Have researched extensively, have started a build - Does anyone have knowledge on the best values for the mixing resistors R-27 and R-42? I realize I may need to experiment with them but I have seen various combinations going different directions gain-wise and am a little confused. I plan to leave t...

Thanks for replies-
I found lots of info under "Vox Top Cut" searches, thanks for tip there. I wanted to ask Roe what he means by a "no load pot"?
Thank you.

Hello- I am in process now of building a copy of the John Mayer Custom Reverb/ AN "Wonderland" amplifier based on info gleaned on this site. Attached is the schematic. My question revolves around the "contour" control, namely C-29 (4n7) and R-51 (250KA pot) of which are across the output of phase in...

Hello- I wish to experiment with a pair of fixed bias push-pull 7591's (instead of 6L6GC) in my next build. Since most of my preamp circuits are for driving 6L6GC's I understand that the 7591's will only need about half of the driving voltage from phase inverter. How is the best way to deal with low...