[sdiy] beginner SDIY... larger Pot values & carbon VS. Metal filmresistors

[David G. Dixon]

> If it's a voltage divider (this can be hinted by three leads
> connected) then I can't imagine it working any differently

That depends on whether there are resistors between the pot and the rails.
I've done this in some of my circuits (for example, on coarse frequency
adjustment pots) to limit the voltage output of the pot to a certain range.
If the pot is doubled, then those other resistors also need to be doubled.

Another situation to watch out for is when an attenuator pot (signal into
one end, the other end grounded, signal out the centre tap) feeds directly
into an inverting summer through a big resistor.  In that case, changing the
pot value changes the shape of the attenuation response (the smaller the pot
value, the more linear the response).
 
If I were designing modules to sell in kit form, I would design in 100k pots
everywhere except where some other value is strictly necessary.  It's nice
not to have to mess around with a bunch of different pot values.

> > And on a similar note; I want to use carbon 5% tolerance resistors in
> lieu
> > of the 1% tolerance metal film resistors.
> 
> All depends on what you're using them for.
> If it's stuff like filter feedback or an oscillator core, I wouldn't
> risk problems.

Accurate resistors are often important, but sometimes 1% resistors are
specified as much for their low temperature coefficient as for their
accuracy.  It's important to be able to gauge when and why 1% resistors are
necessary.

> > I am more of a musician than a technician, so.. Forgive my EE ignorance.

If you really want to build your own stuff, you'll have much more fun if you
gain some understanding of how it all works.  But, not to worry: compared to
music, electronics is a piece-o-cake!