It's been later included as a built-in version in more recent Farfisa organs.
Guts and pics here : http://www.effectsdatabase.com/model/farfisa/sferasound
Schematic of the built-in sferasound in a Farfisa 250 RSE: Parts list for the above schem: Note: on this version, the two controls are the two switches: "ON/OFF" and "FAST/SLOW".
Now some comments by AG:
There's probably a lot to do from this, so let's see what it may lead too... Of course if you have the schematic of the pedal version, feel free to share it here. It is very different, BUT is supposed to achieve identical purposes and sound. BTW the parts in the schem above are fairly available and still quite cheap!analogguru wrote:Now look at the tricky modulation oscillator how the diodes are arranged. I have never seen this before. With changes it can be used in an overdrive circuit too. If you make Rm25 and Rm26 a potentiometer....
And now compare it to the average bootweak-circuit and you will know, why they are boring.
Any input welcome!