Studer 961 - Oscillator Circuit

[Falk]

Good Morning Gentlemen,

I am currently recapping two of my Studer 961 consoles. Also I am doing the post fader direct out mod. Everything good. Great documentation. Studer quality makes things easy.

The onboard oscillator of one of the consoles is modulating its level by 6dB to 10dB with maybe 1Hz frequency. I swapped the IC and changed all the electrolytics in the circuit but the problem is the same.

Any hint where to move on?

Thank you!
Falk

 

[Falk]

Appears to be bad contacts in the frequency selector switches. Thanks for your attention this thread can be closed / deleted.

 

[zamproject]

bad contacts in the frequency selector switches

Exactly what I will suggest... having same issue in the past with the Test Gen card on other Studer series desk.

Not used to the 96x series, but as an advise I'll say that when you don't use the TG it's better to set in OFF position.
For my 169 as 289, the TG signal run on the bus board and to all modules.
Even if not selected as a source input there is a cross talk all over the console...level is low but still hearable in some circumstances, especially the 1k and 10k

Cheers
Zam

 

[Falk]

Thank you for the insight Zam. I ll use the Off switch from now on. After studying the circuit it made so much more sense to have it.