capacitors in SID 8580

Testing/Troubleshooting
1

i just switched my “old” 6581 SID with a 8580, hoping to have a better filter.

so i mounted two 6.8 nf caps as suggested by the schematics, but the filter works like crap!

if i use only one osc, and set that osc to a low pass (in jsynth) if the cutoff is=0 everything is ok. but when i move the cutoff to 2 or 3 it begins to make strange noise, and it continues in the same way even if the cutoff reach 127. it’s not working like a “normal” filter… it only produce noise!!!

should i change the caps?

or is the fact that i’m using PIC 16F877 instead that MIOS??

2

I know this could be stupid to say, but I´ll do it: You did change the voltage regulator, did you? (6581: 12V, 8580: 9V)

3

Did you burn the PIC16f877 with the firmware for the 8580??

Christoffer

4

Did you burn the PIC16f877 with the firmware for the 8580??

Christoffer

no!!

i didn’t remember there were two different versions!

thanks!

5

OK, it was stupid to ask… ;D :wink:

6

Hmm…

Nothing here is stupid to ask.. ;D

Christoffer