bad precision pot?

[Rory McDonald]

What about a digital pot like the Analog Devices AD5220?
Check out http://products.analog.com/products/info.asp?product=AD5220
10k, 50k, or 100k w/ increment/decrement count, 128 positions and powerup
centering.
Would this be an interesting chip to replace some pots?
-Rory Mc Donald
> -----Original Message-----
> From:	jhaible [SMTP:jhaible at debitel.net]
> Sent:	Tuesday, August 10, 1999 4:37 AM
> To:	Martin Czech; synth-diy at mailhost.bpa.nl
> Subject:	Re: bad precision pot?
> 
> 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.
> >
> >
> >
>