PLAN B analog blog

We've shipped something like 36 of these guys and I have head comments
like this now twice.  It's the vactrols, they are all all over the
place as far as response.  There's an easy fix and I apologize this is
happening.

R51 is currently a 5.1K (that's green/brown/red bands).  If you have
the means, change that to a 3.9K (orange/white/red).  This will
compensate for the higher resistance of the vactrol that effects feedback.

R51 is easy to spot. It's about an inch behind the trim pot on the
bottom board, the one with the jacks soldered to it.  It's sort of out
on it's own, not in a cluster with a lot of other components.  If
you're nervous about removing the current one (5.1K), just cut it out
and solder the 3.9 K to it's pads on the bottom side of that board.

- P






--- In PLAN_B_analog_blog@yahoogroups.com, "gabu_004" <gabu_004@...>
wrote:
>
> Hello,
> 
> So just a smal review of the M11.
> Nice timbre and pretty dirty compared to the many other filters out
there! Also I like the 2 
> simultaneous 6 and 12 dB output, can keep something quite fat still
with some thinner and 
> interesting timbral modulations (hi-Q, small bandwidth). The twin
feedback switch makes it 
> one of its kind really! Two resonnance peaks at the same time gives
some interesting results 
> there.
> 
> Just one question for Peter now:
> 
> It says in the specs that it will self osciliate... So far I haven't
achieved to do so, I've put to 
> max the Res and Bandwidth pots, played around with the freq, yes
there's an output(12dB) 
> and the module is powered... Could it be that it doesn't self osciliate?
> 
> But except for the self osciliation expectation, I really love my
new filter and recommend it to 
> everyody out there doing harder stuff...or whatever, everybody, no
matter what hehehe!
>