PSU Studer 169 oscillation

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

AudioIngenia

Well-known member
Joined
Feb 22, 2017
Messages
68
Here is a Studer power supply.
There is a background whistle on all console buses, tuned to 6.8 kHz.
I have tested with the laboratory PSU and the sound is clean.
The problem seems to come from the PSU, but I do not find the oscillation.
I have replaced all the condesadores, the two integrated circuits and checked the rest of the components.
Any suggestions?
gO7UuU

https://ibb.co/gO7UuU
 
I just checked, with the original power supply , in addition to tone also a lot of background noise.
I have also checked with this:
https://szpcsy.en.made-in-china.com/product/qytmkTJxTlcA/China-48V-0-25A-15V2-5A-15V2-5A-triple-output-switching-power-supply-for-audio-equipment.html
With the Chinese psu, the sound is clean
:p
 
mjrippe said:
Yes, get rid of the Studer supply and use the one from China  ;D  Seriously though, the last 169 I worked on it was easier and less expensive to replace the PSU.

PSU replaced by another? What brand and model?
 
AudioIngenia said:
The problem seems to come from the PSU, but I do not find the oscillation.

How did you test it, under the load or without?
Do you have a scope?
BTW, where did you bought the Chinese PSU?
 
Everything has been solved. I have redone the power source. Two 7815 have been my salvation. The perfect voltage, there is no oscillation and the background noise has been reduced considerably.
 
Back
Top