Help! OPL Board difficulties

Testing/Troubleshooting
1

Hi,

I’ve got a problem with my new opl3 module.

In fact it works, but I get a strange, distorted sound (sounds as if the gain was too high). I got only one YAC512 stuffed, and both channels sound the same.

I checked and double checked for short circuits - nothing found. I changed the TL074 chips - no effect.

What can I do? Any hints welcome.

regards, tom

2

Hi Tom,

could it be that you forgot the 22k feedback resistors at IC6 (R6/R9/R12/R15).

If this isn’t the reason, check the audio signal before the output amplifier (e.g., at pin 8 and 14 of IC3) - just connect it directly with your soundcard/mixer input (don’t forget the ground connection)

Best Regards, Thorsten.