Potentiometer selection

[Tony Allgood]

Generally for volume controls and EQ frequency sweeps use log types.
For everything else use linear. 

However, this does not always apply. For example, attack, decay
and release pots in ADSR circuits are log. pots. However, it will not
harm your circuits in any way if you do put the wrong one in. All that
will happen is that the control won't feel right. eg. If you put lins
in a volume control, the volume won't do anything until you reach the
final last bits of the wipers travels. 

Beware, pots are sometimes labelled A and B. B is normally linear, but
it sometimes isn't. As for circuit diagrams, it will often be stated.
But sometimes, it isn't, because all circuit diagrams will have an
associated parts list and it will be on that. However, this is not
normally available to us hackers. There is no way to tell from the
schematic alone, but it is possible to work it out if you know what the
circuit does.

And lastly, audio taper is normally log... But, it could be different.
Soundcraft have their own law which sound nicer than ordinary log/audio
pots. There are reverse-log pots as well.

Good luck

Tony Allgood.

Penrith, Cumbria, UK     

e-mail: oakley at enterprise.net

'I may live in the middle of nowhere, but the views are nice'

----------
> From: DuncanK at kochind.com
> To: synth-diy at horus.sara.nl
> Subject: Potentiometer selection
> Date: 06 September 1997 6:18 PM
> 
> Okay, I've got schematics for various building-block circuits, both
for
> synth modules and for general audio.  How can I tell when to use
audio
> taper, and when to use linear taper potentiometers?
> 
> I presume something like a balance pot:
> 
> Left -----^v^v^v^v-----Right
> 
> With the signal pulled from the wiper, would be linear.  I also
presume
> standard faders would use audio taper pots.  However, when faced with
> gain/cut and freq sweep pots (ala sweep eq's and such) I have no
clue.
> I realize the answer in each of these examples is, it depends...
> 
> But my real question is:
> Is there something I should look for in a schematic, particularly in
the
> way a given pot is used, which I can use to guess whether to use
linear
> or audio taper pots?