Page 1 of 1

SKRM-C8-R02: Oscillation at 280Hz

Posted: Mon Jun 22, 2015 11:09 am
by fjr
Dear Frank:
After having integrated the R02 module into my listening room reverb system, I noticed an oscillation of 280Hz at the outputs of the module, as well as after the buffer amplifiers, when no input signal was fed to he module. The settings were: Prg:"Hall", Pot0: min, Pot1: 35%, Pot2: 20%.
When fed to an audio spectrum analyzer, the level measured to approx. -85dBV. Although this appears to be rather low, it's nevertheless clearly audible when no input signal is present. The input pins (L and R connected) are essentially clean. Other programs also show an oscillation, although at different frequencies.
Strangely enough the self-oscillation disappears when an input signal >-75dB is fed to the module.
Have you noticed anything similar before?
Besides this minor flaw, which could originate in my circuit as well, it's a great module with unparalled versatility.
Best regards

Re: SKRM-C8-R02: Oscillation at 280Hz

Posted: Thu Jun 25, 2015 8:16 am
by Frank
We’ve never seen this before, it could be something in your circuit or it could be something went bad in the module after QC. Do you have a second R02 to swap into the circuit? Could you send your schematic to our support address so we can take a look?

Re: SKRM-C8-R02: Oscillation at 280Hz

Posted: Fri Jun 26, 2015 5:09 pm
by Frank
UPDATE: Been working through the support email, appears the tone is being generated elsewhere in the circuit as it is on the 5V line used to power the module and exists even when module is removed.