MOTM

A vactrol was my problem back when I built my 410.  I held the iron to a leg
for too long and killed it.  I promptly tossed the iron and went out and
bought a Weller WSD80 station. :)

-George

----- Original Message ----- 
From: "Mike Marsh" <michael_marsh@...>
To: <motm@yahoogroups.com>
Sent: Friday, October 28, 2005 8:06 PM
Subject: [motm] Re: To those that have built a '410....


> 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%...