Rheostat alternative

Edutainment · Post by **Edutainment** » Thu Jun 19, 2008 9:39 am

I'm making a Little Gem (runoffgroove.com) portable amp and I can't find a 25W rheostat. What can I use instead (or does anyone Canadian know where I can get one in Mississauga or Toronto?)?

nitro2k01 · Post by **nitro2k01** » Thu Jun 19, 2008 11:56 am

If you want to, you can leave the rheostat out for now, which leaves you with an amp without master volume, but still working. Just connect out to the capacitor.

Post by **Triton** » Thu Jun 19, 2008 1:44 pm

a 25 ohm potentiometer will work pot is 3 terminal rheostat is 2 terminal, if you leave one leg of the pot disconnected it works as a rheostat

Edutainment · Post by **Edutainment** » Thu Jun 19, 2008 2:40 pm

Rheostats are meant for high power situations right? I don't think this is really high power but there has to be a reason they use arheostat, 'cause they use a regular pot for gain.

EDIT: Cool, The Source had a 25ohm rheostat. I didn't expect that 'cause they're not the greatest place for parts (way overpriced too). Problem solved. Thanks anyways guys.

timmeh87 · Post by **timmeh87** » Fri Jun 20, 2008 10:05 am

I think technically any potentiometer can be used as a volume knob in that configuration (its just a voltage divider).

Usually you find something like 100k inside portable electronics and stuff.

Anyways, its proper technique to adjust the volume BEFORE the amp, not after it. You might consider making this change. Although on such a small amp it probably dosent matter (on a larger on you may very well need a 25Watt pot to avoid fireworks)