Trim capacitors

[upspoon12]

Hey guys,
So after a few search attempts I couldn't seem to fi d anything that I was looking for, and that's an answer to thisquestion.

I get trim pots,  but how about trim capacitors?  What is a practical application for them in pedal or music world? 

[greaser_au]

because of the physics of capacitors, and the limits of simple (=cheap) mechanical engineering, reasonably sized trimmer caps (e.g. might fit in the same footprint as a trimpot) tend to be in the range of 1s/10s/100s of pFs. so not very useful at audio frequencies.  I've seen  compression and vane trimmers over the years.

As an example a modern(1970's era or later ) transistor radio tuner might be 60-160, 10-200 or 10-365 pF (with a typical size of, say, 20x20mm (3/4x3/4")).

david

[Quackzed]

try searching 'cap blend pot'. while it's not 'precisely' a variable capacitor, it functions -in most applications- like a variable cap... its basically a small capacitor in parallel with a 100kish pot and a big capacitor---

http://www.diystompboxes.com/smfforum/index.php?topic=97724.0