Space Station SST 282 oscillation problem

[tommia]

The unit works fine in echo mode.
In reverb mode  it is ok if  the feedback is set between 0 and 5.
After 5 it oscillates, the frequency is exactly 2kHz and 4kHz , 6kHz.

Any suggestions?

 

[David Kulka]

Maybe 1 or more bad IC's on the RAM board, they are a common failure.

 

[tommia]

thanks Dave,
but this is not the case.
I've installed dip switches and with switch 3 closed (1), you bypass the ram's. DAC is connected to ADC.
Oscillation still occurs in the same situation.

 

[tommia]

  problem solved. Caps were still good. one broken IC in the digital section