Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Toxophilite on September 08, 2020, 03:04:18 am
-
I have a stereo AB763 deluxe reverb I built a while back(see schematic) using 7189 (or Russian equivalent tubes)inspired by the 6BQ5 tremelux.
it currently has a standard fender AB763 2 tube reverb circuit and a bias vary tremelo
The reverb is on channel one and the trem mostly affects channel one and channel 2 less so
Channel one is a deluxe reverb with bias vary trem
Channel two is just a straight deluxe amp (I use this channel for echo)
Channel one, pre reverb, can be mixed into channel two's power amp
What I was thinking of doing was:
- switching the reverb to the type used in an Ampeg super echo twin with channel one's power amp driving the reverb tank and then adding it two channel two via a recovery circuit that uses 1 triode. rendering 2 reverb triodes redundant, and perhaps the mixing triode too.
- Switching to S Luckey's Tremor-lator circuit which would also free up a triode so that I could have full tremolo with any distortion or other wonkiness of bias vary,
This would basically take 2 dual triodes out of the amp Which would have a negative side effect of knocking B+ voltage up. The amp uses a twin reverb PT to provide enough current but it ends up running the Russian power tubes at pretty high voltages
Something I might have to address if I decide to do this. i might have to swap the old PT back in...if I still have it.
-Is it possible with the tremorlator running into two channels to have some sort of phase reverse circuit or modulation flip on trem going to one channel so the trem pumps from either amp/speaker at different times for kind of a stereo tremolo effect??
Another option I just thought of would be JUST to switch to the tremorlator then ADD the ampeg style 'stereo' reverb using the free triode. Thus having both reverbs..oooooo ahhh. Also no resulting B+ jump nor need to swap in a new PT. This would necessitate adding a reverb tank, another potentiometer and another footswitch jack.(r)
opinions, ideas?
-Thanks
-
-Is it possible with the tremorlator running into two channels to have some sort of phase reverse circuit or modulation flip on trem going to one channel so the trem pumps from either amp/speaker at different times for kind of a stereo tremolo effect??
The TON is a simple, no frills, mono circuit. It has only one output.
-
Use Joe Piazza's re-drawn schematic, Ampegs version will give you a headache :icon_biggrin:
-
-Is it possible with the tremorlator running into two channels to have some sort of phase reverse circuit or modulation flip on trem going to one channel so the trem pumps from either amp/speaker at different times for kind of a stereo tremolo effect??
The TON is a simple, no frills, mono circuit. It has only one output.
I realize it's 'mono' but couldn't one use it to provide tremelo to two amps? (in the same cab of course) Like one can do with bias vary(por Does it work on the preamp rather than the power amp?
-
I think you would be better off to use the tremolo circuit from the AC-15. It has dual outputs (C29, C30) that are 180° apart. All you have to do is figure out where to insert the signals. Needs to be somewhere in the preamps. Let us know how this turns out.
https://el34world.com/charts/Schematics/files/Vox/Vox_ac15.pdf
-
That vox circuit looks neat but likely too much reno for what I was intending. I think a replacement of the tremelo circuit would be cool, especially as it's a deluxe and live (when i used to play live pre pandemic) it often runs close to it's clean limit.