Quick note since I’m at work.? I’m looking at the big, fold-out schematic at the PRA EXP WAH Circuit all the way at the top right.? The foot pedal voltage comes in on EI(52) and buffered by IC3. The output goes through LEDs PH1 and PH2 that shine on internal photocells for the volume control.? It also goes to PH3, over to the left, to control the wah (nothing to do with the brilliance or VCFs) The catch is that, since they’re in series, you can control wah without volume in the LED/photocell modules.?? You could just use a DSDP switch to bypass the photocell pins on PH1 and PH2 so the pedal doesn’t control the volume.? It might mess with the level so it could need a couple of resistors in series with the bypass path so the volume is the same.
Not been here for a long time... but I thought I'd make a quick post.
I've been playing the 80's a lot recently... and have gotten into altering the Brilliance fader during play.
It's quite tricky to get a free hand in sync so I thought I'd look at the "wah" function on the expression pedal.
First thing that struck me was that along with "wah" you also must have volume. Not what I'd like. I'd like the volume to be set and just open and close the "Brillinace".
Second thing was that I thought I might be able to "modify" to get just "wah"... but looking at the schematic I cannot fathom how the "wah" function works. It doesn't seem to be a direct replacement for the Brilliance lever...? Could anyone please shed some light on it please...?
So, apart from disconnecting the Brill pot's wiper and putting it to a foot pedal sweeping between +/-15 volts - which was an idea I had - can anyone think of a quick way of getting that function...?
