Crate GFX-15

[wadehavens]

Hi there! I'm in need of a schematic for a Crate GFX-15. I purchased this amp for my daughter from a thrift store for use as a practice amp. It works, but it has some issues after about 20 mins or so of playing. Also, in case I can't figure out what is wrong with it, I'm considering using the DSP interface with another chip amp I'm working on. It would be nice to get the pinout to the daugter board.

Thanks in advance!
Wade

[Enzo]

Oh geez, these things are so simple.

If it warms up and gets silly, check:
1. is the TDA amp chip getting hot? Change it.
2. make sure the cutout contacts on the headphones and external speaker jacks are OK. Closed contact resistance must be under 1/2 ohm.
3. watch the output pins of the op amp ICs for any DC offset. Pins 1 and 7 on the small one, and the corner pins on the TL074. Not worried about a few millivolts, we are looking for several volts. Change any that are offset.
4. check solder on all jacks and all controls.

[wadehavens]

Wow, very fast reply...Thank you very much for the schemo and the tips. I shall use them wisely!!

Wade