bad precision pot?

[jhaible]

No other observations.
I don't like them on synths, nevertheless. With a coarse and fine pot,
you can make fast changes as well as small precise ones. With a 10-turn
you end up dialling like a madman - no you rather end up using the pot
less than you would otherwise.
There is one exception to this, and that's the use of special coarse / fine
knobs that have some gear inside. But these are very expensive, and
not exactly tasteful looking.

(Speaking of VCO frequency applications, I was. There would be other
applications where it might make more sense.)

JH.


----- Original Message -----
From: Martin Czech <martin.czech at intermetall.de>
To: <synth-diy at mailhost.bpa.nl>
Sent: Tuesday, August 10, 1999 8:58 AM
Subject: bad precision pot?


> I've read somewhere that precision 10 turn wirewound pots have problems.
> The slider seems to stick on the windings, that means problems with
> resolution.  And it was said that mechanical shock or vibration would
> change the value.  The author claimed that he would rather prefer ordinary
> pots, maybe two, one for coarse and one for fine.
>
> I was sceptical.
>
> I took a 10 turn 10k Burns with 10 turn display/knob for my test
> oscillator.  I doubt that I get better resolution with a carbon or
> other type pot.  I tryed also reasonable shock and vibration (finger,
> pencil, screwdriver) and I couldn't find any change of value (even if
> the mechanical break was inactive).
>
> So, I came to the conclusion that these guys are expensive, but worth
> the money.  Especially for analog coefficents.
>
> As they are wire wound they should have high inductance, however.
> Won't harm for dc control voltages.
>
> Any other observations?
>
> m.c.
>
>
>