calrec PQ1161-02 Oscillating/motorboating

[RSRecords]

Hi, I've got a racked pair of Calrec PQ1161s channel strips that  motorboat or oscillate at full gain or with a healthy low shelf boost. Any ideas?
It's fully recapped. I'm not seeing any ripple from the power one supply.

Thanks

 

[radardoug]

Well, oscillation in this mode is probably because in a console, its fed by a beefier power supply with lots of cap in the filters. Try adding some large caps on the supplies. If the oscillation changes you are on the right track.
Also check your grounding is good and all necessary ground points are connected.

 

[RSRecords]

Well, oscillation in this mode is probably because in a console, its fed by a beefier power supply with lots of cap in the filters. Try adding some large caps on the supplies. If the oscillation changes you are on the right track.
Also check your grounding is good and all necessary ground points are connected.

Well the PSU is probably overkill already (condor, +/-24v 5amp) but it is from the 90s it seems. I wasn't seeing and ripple but perhaps its due for a cap replacement.