Modding a tube tremolo into a tube ring modulator...

[Taylor]

http://www.blueguitar.org/new/schem/peavey/valverb.gif

There's the schematic for the Peavey Valverb. I'm wondering if it's possible to easily mod the trem section into a ring mod by increasing the maximum speed of the oscillator. I'm guessing it's a matter of swapping a resistor or two, but I could be way off. Can anyone take a look and tell me what you think?

[soulsonic]

If you mod the speed of the oscillator, you can get effects that might sound kinda similar to a ring mod, but it won't be an actual ring mod.

[frequencycentral]

The link in your post seems to be down.

........but have a look at the Vibracaster thread: http://www.diystompboxes.com/smfforum/index.php?topic=70160.0

It's still on my breadboard, but now perfected, and the finished pedal is halfway through construction.

I do have some similar ideas, but i think it would be closer to a Nyquist Aliaser/Analogue Bit Crusher than a ring mod. As soulsonic says, the speed would need to be increased into audio range  -the Vibracaster uses a PSO - so it's a delicate balance between resistor and capacitor values. The Nyquist Aliaser/Analogue Bit Crusher work like sample and hold - so the LFO wave would have to be a pulse with a short duty cycle - this could be achieved using a low value cap in series with the LFO feed into the cathode to turn the sine into a 'blip'. Also, the capacitor/resistor between the two triodes would have to be replace with a single 'hold' cap to ground. The main problem with these sorts of circuits is oscillator bleed into the audio path, I guess you could get around that by using phase cancellation. Also Nyquist Aliaser/Analogue Bit Crusher/Ring Mod are not very 'musical'  effects - they can make one unholy racket. I don't know if it would work - it's on my 'to do list' - but way down behind some other stuff I want to try first!