You also might check if the vactrol for filter 3 is in correctly. Not
that I would have any experience with that or anything...
--- In motm@yahoogroups.com, Scott Juskiw <scott@t...> wrote:
>
> My first guess is that something is wrong with LFO #2 and the output
> is stuck near the positive rail. Have a look at U5 pin 14 to see if
> LFO #2 is oscillating. If that looks good then trace the LFO signal
> through U7B and then into the driver for D3 (U4B, VR4, Q9, and Q6).
> That's where I'd start looking.
>
> >I just finished building my first kit, a '410, and it sounds great...
> >mostly. Sadly the third filter doesn't seem want to play ball.
> >
> >It passes audio, but it's stuck at the highest setting, up around 30k,
> >rendering it useless. No cv or knob twiddling makes it budge.
> >
> >Also - and maybe this is related - the second LFO doesn't produce an
> >effect on the second or third filter. So basically the LFO switch does
> >nothing. The first LFO works fine.
> >
> >I pulled the '410 out of the rack and detached the pcb from the bracket
> >(sigh) to have a good look, but the soldering looks fine. There don't
> >appear to be any shorts, unless they are a case of solder from the via
> >holes (which are all filled) touching the underneath one of the mounted
> >items, if that's even a concern. Also, I checked the resistors in the
> >"filter 3 section" of the pcb (so R8, R10, R42, R58, R59) and
> >everything is in the right spot.
> >
> >Given that this is the first time I've done soldering work of this
> >scale since high school, I'm sure it's something I've done wrong, for
> >example that one of the connections isn't soldered well enough, but I'm
> >hesitant to just pull everything off the pcb and start again. Do these
> >problems sound like they can be traced back to specific
> >resistors/capacitors/etc?
> >
> >If anyone has any suggestions they would get my infinite gratitude. I'm
> >really happy with the sound of the unit thus far, now if I can just get
> >it 100%...
>