Originally Posted by: LordathestringsAmpegs were designed to deliver great clean sound, with lots of headroom. Everett Hull hated Rock'n'Roll, remember? So when an Ampeg is pushed into distortion, it doesn't sound like lesser amps that were intended to get buzzy. A distorted Ampeg sounds like something that has been pushed to the limit, and is going to utterly destroy anyone who is fool enough to ask for more. And because they were built with massive transformers and conservative tube utilisation, they are seriously loud by the time they get dirty. I still hold that the true test of a player's finger-tone is what they sound like plugged straight into an Ampeg.

But, if you want to do the pedal thing, Ampegs will cheerfully accomodate you. I had an absolute blast trying out a Digitech Bad Monkey with my VT-22. The only reason I got rid of that pedal is the nasty tone-sucking things it did to my sound when I shut it off. With true bypass, that would be my personal favourite stomp box.

My thought was that, if I were able to push this amplifier harder, I'd end up with distortion character more along the lines of, say, a Hiwatt, as opposed to the more "saturated" sort of distortion you get with a older Marshall -- realizing it's an oxymoron, I'm tempted to say a "cleaner" sort of overdrive with less crunch.

Here's the circuit:

http://www.kbapps.com/audio/schematics/tubeamps/ampeg/gu12.html

I see some experimental opportunity in the values of R14 and R21; it looks as though a lot of signal gain is pulled down after the second preamp and in the reverb recovery. I was also wondering if a 12AX7 in place of the 12DW7 would be of any interest -- hitting the 7591s with 12AX7 gain in the phase inverter instead of 12AU7 gain (the 12DW7 is half AX7, half AU7). I'm going to tinker here a little to see if I can get the amp to open up a little more at lower volume levels.

This was an interesting thread I ran into:

http://p210.ezboard.com/fampworkshopfrm13.showMessage?topicID=114.topic

Note tonepoet's comment about the 7591s. I think that that had something to do with how I ended up with this amplifier -- it had been donated to a charity that my father used to work at, back around 1999, and I got it quite cheaply after Dad (knowing I was amplifier-less at the time) tipped me off about it. You couldn't get JJ or EH 7591s back then; your only shot was at used pulls (mainly from Fisher hi-fi amps), and even then they were expensive. The previous owner probably thought it could no longer be retubed fresh, and gave up on it. Imagine my delight when I brushed the dust off of it five or six years later, and discovered that new 7591s had become available since then. :)

It will be interesting to see how the pedal setup works out. That's going to be a real challenge, but I'm looking forward to it.

C.K.