Heya,
I recently bought a used Doepfer A-121-3 slimline filter and unfortunately it arrived in a sad state. With the Level knob anywhere below about 3 o'clock there's little to no audio output unless the cutoff knob is between about 1 o'clock and 3 o'clock. When the cutoff enters and exits the 'working' range there's an unnatural pop and/or signal distortion sound before sound is abruptly heard. With the Level knob maxed there is audio through the full range of the cutoff, but it's character is full saturation of course and the filter effect is barely noticeable.
The Resonance is acting weird too. It seems to start self resonating very early in it's range but then cuts out at it's high range.
The problem is the same on all of the outputs.
I checked that the ribbon power cable is connected properly to the back. I also checked it with a different rack/power supply/audio source. There's nothing visibly wrong with the module.
There's one trimmer pot on the circuit board so maybe it got bumped at some point and needs re-calibration? Anyone here know how to do that?
Thanks in advance for your expertise!
trevor
I recently bought a used Doepfer A-121-3 slimline filter and unfortunately it arrived in a sad state. With the Level knob anywhere below about 3 o'clock there's little to no audio output unless the cutoff knob is between about 1 o'clock and 3 o'clock. When the cutoff enters and exits the 'working' range there's an unnatural pop and/or signal distortion sound before sound is abruptly heard. With the Level knob maxed there is audio through the full range of the cutoff, but it's character is full saturation of course and the filter effect is barely noticeable.
The Resonance is acting weird too. It seems to start self resonating very early in it's range but then cuts out at it's high range.
The problem is the same on all of the outputs.
I checked that the ribbon power cable is connected properly to the back. I also checked it with a different rack/power supply/audio source. There's nothing visibly wrong with the module.
There's one trimmer pot on the circuit board so maybe it got bumped at some point and needs re-calibration? Anyone here know how to do that?
Thanks in advance for your expertise!
trevor
Statistics: Posted by tdutz — Sat Jun 01, 2024 12:54 pm — Replies 1 — Views 71