[sdiy] Cooking pots

[fmg]

On Tue, Sep 13, 2011 at 3:29 AM, Paul Perry <pfperry at melbpc.org.au> wrote:
> Erik Dower - who started this thread - appears to be havign some trouble
> posting to the list. He's asked me to send this for him:
>
> Erik:
> "I thought about filing off the material but I'm not sure how good of a
> solution it is to open up a quad bourns sealed pot.  I've never attempted
> such a thing but it seems perhaps as messy as my proposal?

I don't think filing would be a good idea due to the noise that would
produce the
scratches and the possibility of multiple cuts to the track.
Burning is definitely a bad idea because the extra carbonization will
surely reduce
the total resistance, not to mention the weird nonlinearity would
experiment the wiper
trying to slide in a (new) totally irregular terrain.

> The pot is in a feedback path of an opamp in one band of an EQ.  The band
> goes from -infinity to +6db with center detent @ 0db, and the goal is to get
> more gain out of it.  Here's the schemo:
> http://www.muffwiggler.com/forum/userpix/1370_screen_shot_20110911_at_92828_pm_1.png

Increasing the pot value would probably increase the gain range of
last opamp but
the filter characteristics would be deteriorated, unless you
recalculate the value of
the passive network to accomodate the new pot, in wich case you will end up with
a filter of exactly same characteristics of the one you already have
with no mod at all.

Sorry for the bad news.

Fabio
.