I am just plugging an electric guitar directly into the input. I don't
have the actual circuit here with me right now but the schematic is
here (see page 5):

http://makezine.com/09/crackerboxamp/

I believe the + of the input goes to a 0.01 uF capacitor, the - goes
to ground.

BTW can anyone explain how to add an XLR out (either balanced or
unbalanced) to directly connect the amp to a mixer or recorder?

Thanks

On May 31, 9:08 am, MadEngineer wrote:
You failed to mention what you have on the input, which can be a
factor