JC-120 Chorus Question

[rf7]

The manual says that there should be a 25Vpp triangle wave at the output of IC5, but I am getting a very small output at that point and VR1 does not affect it at all. Can someone explain how the Q36 to Q35 to IC5 circuit is supposed to work? It looks to me like the output of channel 1 feeds Q36, which (in this amp) turns a sinusoidal input into a square wave. I thought maybe Q35 would have a triangle wave output, which would then be amplified by IC5, but I see nothing of the sort. The chorus does seem to work, despite this lack of a large signal at the output of IC5. I do know that the speed & depth controls do not affect the chorus. The circuit was modded and I put it back to stock, trying to get that waveform for the Chorus adjustment.

http://bmamps.com/Schematics/Roland/...e%20Manual.pdf

[rf7]

I figured it out. Q35 basically acts as a switch. It grounds the input of the triangle wave generator at IC5, which turns it on.

[Jazz P Bass]

Cool.

Thanks for the update.