An easy trem+vibrato - looking for options

[Mark Hammer]

I picked up a small Garnet solid-state amp a few years ago at a curb on garbage day, and gutted it, to re-use the nicely-tolexed cab and amp chassis (w/transformer)***.  I recently picked up a nice 10" alnico Weber speaker that fits perfectly in the cab, and I painted and re-legended the chassis, popping in a few extra holes. 

The intent is a basic all-in-one amp of around 10W or so.  No overdrive.  Just treble/bass, long/medium/short echo settings courtesy of a Rebote 2.5, and speed/depth for tremolo/vibrato, with only one selectable at a time.  Any other things can be inserted ahead of the amp.  And, as luck would have it, the cab is exactly the same dimensions as my tweed Princeton, so I can park them side by side.

So, I'm going through all my schematics, looking for something that could provide basic pitch-wobble vibrato function, and be easily amended to provide tremolo with a DPDT toggle.  At present, the best candidate seems to be a modded Phase 45, that uses an additional stage, borrowed from the EA tremolo.  The P45's LFO would modulate the drain/source resistance of a pair of 2N5952s (plenty of matched pairs sitting in the bin) plus a drain/ground FET, as in the EA trem, to set and vary the gain of a single-transistor stage.  I either pick the output of the P45 (wet only) or the output of the EA gain stage.

A couple of questions emerge from this starting point:

1) Is there a better or more convenient platform to achieve what I'm aiming for?  Doesn't need to be the world's greatest trem or vibrato- I've got oodles of other pedals to do that.  I'm looking for simple, convenient, functional.

2) If what I described IS a solid platform to work from, do I need to use the same FETs for the P45 and EA trem sections, or could I mindlessly use 5952s for the vibrato and a J201 for the trem?

3) If a single curent-limiting pot from the P45's LFO (in place of the 3M9 resistor) likely to be able to produce pleasing and useful ranges of depth for BOTH functions?  I'm thinking that a 100k rev-log speed pot would be appropriate, since neither vibrato or tremolo are particularly audible at slow phase-sweep speeds.  However,  I suspect the depth range for pleasing vibrato and tremolo is not identical.

I'm open to ideas.

***Would have brought the amp back to life but I could never get my hands on a schem for it anywhere.  Still have the board though, if anyone wants it.

[midwayfair]

PMed.

[tca]

Hi, do you have any ref for the circuit of that amp? I've been searching the web with no results, yet!

Cheers.

[PRR]

> as luck would have it, the cab is exactly the same dimensions as my tweed Princeton

I suspect, not luck, but simple copy-cat. At the time, Fenders going into Canada paid an import duty. Gar saw he could build similar stuff, even in small quantity, sell it locally for less than a Fender, *and* proudly Canadian. While Tweed Princeton is pre-Transistor, it is a good size so why make new jigs?

No opinion on your question. I'd breadboard it trying more and less knobs and various FETs before doing the final build.