Small Stone --> Tremolo?

[Jack]

Is it possible to turn the small stone into a tremolo... ala the red whitch thingy... As opposed to the "tremolo like" effect of cranking the speed.
Cheers

[Vsat]

Interesting idea! Yes, it should be possible - and 3 of the CA3094 chips could be eliminated, leaving just the one for the LFO and another for a variable-gain amplifier. Look up the schematic for a CA3080-based VCA circuit - this would be similar. The gain would vary in decibels/sec (rather than volts/sec), thanks to the way the LFO circuit drives pin 5 of the CA3094. You could use a pot and series resistor to inject a fixed current into pin 5 to control the depth of the effect (by setting the minimum gain). A load resistor from pin 4 to ground or mid-supply reference would control the overall  gain. Potential issues are hiss and LFO ticking - but these would be the same problems as the Smallstone has by itself... and since only one CA3094 is in the audio path, hiss would be less of a problem. Fun idea - worth giving it a try!
Regards, Mike

[Mark Hammer]

Hi Mike.  yer up late too, eh?

The phase-filter mod that I keep nagging folks about has an interesting property when the SS is switched into vibrato mode.  While it is NOT a true tremolo, the combination of modulated allpass and lowpass stages has a way of fluctuating in apparent volume because of the fluctuating removal of high end.  It ends up sounding like a strange combination of vibrato, tremolo, and rhythmic wah.  That may be just what you're looking for.

[Vsat]

Hi Mark,
Ya caught me...
Check out www.pmerecords.com and go to Equipment then Keyboards - incredible collection of PCB jpgs - neat stuff.

I was thinking more on the lines of a simple build-it-from-scratch tremolo. A correction  - I said hang a load resistor from CA3094 pin 4 - it should actually be pin 1 - which is the OTA output pin. Choice of using the internal buffer or not using it - might as well use it.
Regards, Mike

[puretube]

Note: because of the "hypertriangle-iness" of the SS LFO,
such a tremolo - though doing its job - may not sound as
musically satisfying as expected...