OB-8 weird hiss / noise on all triggered notes

[WhinyLittleRunt]

Follow up from my previous thread about OB-8 recapping, I have an example of the issue I'm hearing with any note triggered.



The first chord is just a brass patch with both OSCs on, then followed by the same chord/notes with the OSCs turned off (you probably have to turn the volume up some to hear it because I don't process the track to add any gain). You'll hear the harsh, digital-sounding noise I'm hearing behind all notes, mostly apparent on low and quiet notes, and the worst in unison mode. I didn't even think to turn off both oscillators and see if it followed just the key triggering but it does. Couple things I did notice if it helps:

*The noise/hiss "follows" the filter parameters, so for example, if I have a short decay or a long release, if I play those notes without the OSCs on, the noise follows the settings.
*Tried with a MIDI keyboard hooked up to verify it wash;t just the keyboard itself.
*Set it in manual mode to make sure it wasn't just crappy patches.

[rhino]

First guess is a vintage op-amp dying.

[WhinyLittleRunt]

Not a leaky capacitor issue?