recurring distortion on V376 preamp

[ToniTonmann]

Hello everyone,

i have some strange problems with one of my  V376 preamps (recapped/serviced in 2015): months ago it started to distort the signal, so i sent it to a technician (Vintagecity, Germany) for repair. He said he found nothing, all measurements were fine and sent it back (and suggested that it might have had a problem with the housing which got "fixed" the moment he opened it). Back home it indeed worked for a test. Now, a few weeks later, it is distorting again.  I've tried it in different slots in the rack and it's just that module that keeps distorting.

Can anyone give me a hint what could cause this ? Is there anything i (being a complete layman) could look for ? Regarding electronics i only have basic soldering knowledge, but have often found help here for my vintage outboard. Thanks in advance.

 

[mjrippe]

Likely a broken solder joint or corroded contact.  Visual inspection may find it.  If re-seating it, flexing it or wiggling it in the rack makes the problem come and go, just re-flow all the solder joints on the connector.

 

[ToniTonmann]

Good idea, just remember there was some crackling when i wiggled in the rack. I'll try that and report, thanks !

 

[ToniTonmann]

Likely a broken solder joint or corroded contact.  Visual inspection may find it.  If re-seating it, flexing it or wiggling it in the rack makes the problem come and go, just re-flow all the solder joints on the connector.

That was it, the input solder contacts were completely gone, i wonder how there was sound at all. Fixed it and it's working fine now.
Thanks a lot again, love this forum  8)