I have put together my first x0xb0x and I'm struggling with getting it up and running. From the output I get very faintly the tones from the oscillator and on top of that a very loud noise that seems to trigger each beat.
What I have tested so far:
- Voltages from PSU are ok
- VCO seems to work, scope looks fine
- Filter probably ok... Tone at R46 fine. However, noise present at R72.
- Noise present at C38 at VCA output
- Voltages at BA6110 seem to be ok
- Digital part seems to work fine
I have attached some scopes:
- Ba6110, Pin 8
- D35 (envolope out?)
- BA6110, Pin6
How can I figure out whether the noise comes from the filter, the envelope or the VCA?
Any hint would be greatly appreciated!
Thanks,
Christoph