Hi!
I've just finished building Tri-Vibe using layout from ROG. It works, but with some issues. First of all, I hear strong LFO ticking when Depth pot is turned to maximum or somewhere nearby. Any idea what may be the cause? Second thing - Swirl and Whirl settings causes circuit to work rather like tremolo than anything else. But it's not that important, I can live with it. But the ticking is ruining this circuit for me. I'm using LM13600N chip, TL062's and TL072.
The LFO in this circuit does not tick if properly built. A 10n+100k couple around pins 1 and 2 of U3a prevent ticking by reducing the slew rate during transitions. As you report the circuit is actually ticking and two modes are not working as expected, it is clear that there is something wrong with your build. I suggest you do a thorough revision (once again) looking for shorts, wrong connections, wrong part values, etc. and post the voltages on every pin.
Thanks for your response. First of all, I forgot to thank you for this great circuit. Even in this half-baked state my Tri-Vibe sounds wonderful and retro - it almost made me cry:).
I've checked my components and wiring. It turned out, that problem with other modes than vibe was in bad cable on output (it distorted sound, so it was little choppy, it wasn't that obvious in vibe mode). Now it's fixed.
But LFO is still ticking. When I turn depth pot above 14 hour, it's noticeable. I've checked components and traces - everything looks OK. I also measured voltages - here they are:
IC1
pin 1 - 4,5v
pin 2 - 4,48v
pin 3 - 4,07v
pin 4 - 0v
pin 5 - 4,46v
pin 6 - 4,39v
pin 7 - 4,13v
pin 8 - 8,94v
IC2
pin 1 - 4,46v
pin 2 - 4,46v
pin 3 - 4,43v
pin 4 - 0v
pin 5 - 4,52v
pin 6 - 4,38v
pin 7 - 3,18v
pin 8 - 8,92v
IC3
pin 1 - 3,44-5.44v (slowly alternates)
pin 2 - 4,39v
pin 3 - 4,12-4,73v (slowly alternates)
pin 4 - 0v
pin 5 - 4,44v
pin 6 - 4,44v
pin 7 - 4,18-4,65v (slowly alternates)
pin 8 - 8,88v
IC4
pin 1 - 1,26v
pin 2 - 5,35v
pin 3 - 4,67v
pin 4 - 4,67v
pin 5 - 5,96v
pin 6 - 0v
pin 7 - 5,97v
pin 8 - 4,88v
pin 9 - 4,38v
pin 10 - 5,49v
pin 11 - 8,86v
pin 12 - 5,52v
pin 13 - 4,67v
pin 14 - 4,67v
pin 15 - 5,34v
pin 16 - 1,24v
The only thing that differs my build from layout is that I didn't have 3,9K resistors, so I used two 3,3K+68ohm pairs instead.