Neyah wrote:I have pretty much no signal if the cutoff isn't far away the 3/4 of his course.
this probably means that the cutoff frequency is very low (which is not normal UNLESS there's a "extended cutoff range" mod, and there probably is)
I have no sound if the resonance isn't in max, but the sound is very very low.
this smells like the main output from the filter isn't reaching the VCA
the filter output (from C14) goes to two places:
1. to the VCA (via C21) .. this is the main path
2. to the resonance pot, from where splits and goes to yet another two places:
2.1. back into the filter - this is the feedback path, and creates the actual "resonance" effect
2.2 to the VCA (via C20) .. this is used as gain compensation..
since the ladder filter loses a whole lot
of gain when the resonance is increased (since it's achieved with negative
feedback), the circuit has a compensation:
the more you increase the "resonance" - the more of the filter output (coming from the resonance pot) is also going to the VCA to bring the gain up
in your case, if you only hear the filter when the resonance is increased - it smells like the filter's main output path (the one going to the VCA via C21) is missing (and you're only hearing the "compensation" part)
i hope this helps