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previous: Fopoman Jon, do you happen to have schemati... -- 9/10/2000 9:56 AM

Re: Harmonic Tremolo in a pedal?

9/10/2000 1:34 PM
jon	Re: Harmonic Tremolo in a pedal? hi, I'm using small Chicago Standard channel mount trannies for all my tube footpedals. The ones I have measure 2.25 X 2 X 2 inches or so. There's an unequal CT on the secondary, with rectification and twiddling the R-C values, I usually run between 200-300 plate volts on the dual triodes or pentode/triodes. I do the design work with a regulated variable DC supply to see if the plate voltage affects the behavior of the effect. On the trems, anything 160-220 plate volts has worked fine for me. My tube wha was real finicky. These trannies will handle 4 12AX7's. The main consideration has been the footprint of the enclosure, proper placement of components to minimize hum, and shielding. Nowadays, I'm welding up my own steel boxes (done about 10 to prototype different circuits)as nothing commercially available suits my needs. This gives me the option of setting all my threaded studs prior to finish "body work and paint", so no screws are visible in the finished product. I have been advised that my setup is not up to the various consumer product codes as I use detachable power cables. Since they're solely for my use, I'm not going to bother with the AC wallwart and multiple voltage multiplier circuits that would be necessary for a commercial offering. As for schematics, I'd suggest picking up KOC's TOT, TUT and TUT 2. I found that by using his free-standing reverb wet/dry splitter/mixer as a guide, I was able to sub in the Fender circuit as he's presented it, with minimal changes in component values. You should really experiment here; for me the learning process was invaluable. I'm sure these things can be done with small signal transistors, to get around some of the problems I've noted above. Instead of going in that direction, I find myself way more interested in exploring what can be done effect-wise with tubes.... Cya, Jon

9/10/2000 1:34 PM

jon

Re: Harmonic Tremolo in a pedal?

hi,
I'm using small Chicago Standard channel mount trannies for all my tube footpedals. The ones I have measure 2.25 X 2 X 2 inches or so. There's an unequal CT on the secondary, with rectification and twiddling the R-C values, I usually run between 200-300 plate volts on the dual triodes or pentode/triodes.

I do the design work with a regulated variable DC supply to see if the plate voltage affects the behavior of the effect. On the trems, anything 160-220 plate volts has worked fine for me. My tube wha was real finicky. These trannies will handle 4 12AX7's.

The main consideration has been the footprint of the enclosure, proper placement of components to minimize hum, and shielding. Nowadays, I'm welding up my own steel boxes (done about 10 to prototype different circuits)as nothing commercially available suits my needs. This gives me the option of setting all my threaded studs prior to finish "body work and paint", so no screws are visible in the finished product.

I have been advised that my setup is not up to the various consumer product codes as I use detachable power cables. Since they're solely for my use, I'm not going to bother with the AC wallwart and multiple voltage multiplier circuits that would be necessary for a commercial offering.

As for schematics, I'd suggest picking up KOC's TOT, TUT and TUT 2. I found that by using his free-standing reverb wet/dry splitter/mixer as a guide, I was able to sub in the Fender circuit as he's presented it, with minimal changes in component values. You should really experiment here; for me the learning process was invaluable.

I'm sure these things can be done with small signal transistors, to get around some of the problems I've noted above. Instead of going in that direction, I find myself way more interested in exploring what can be done effect-wise with tubes....
Cya,
Jon

Replies:

Scott Swartz I have built a couple of tube pedal... -- 9/11/2000 5:02 PM