Bad caps???

I have a BAT VK-3ix preamp that I think is having some kind of issue. I got this unit used several years ago and recently I’ve noticed that every now and then the right channel gets distorted. Almost like a radio station just out of tune on an old analog rig. The sound also drops in and out of volume slightly. This only happens for maybe five seconds and generally within the first 10 min of operation.  I’ve replaced and swapped tubes around but the sound still persists.

The unit is probably 10 years old by now. Is this what bad caps or going bad caps sound like?

I suggest you post a message on Amp/Preamp Asylum

For the subject title you might try something like,

Ping: Victor Khomenko. Problem with BAT VK-3ix preamp.

Then post your question in the box.

Victor frequents the Amp/Preamp Asylum regularly.

Victor Khomenko

I had exactly the same problem a few years ago with a McIntosh preamp.  I sent the unit to Mac and they sent it back with a clean bill of health.  I put it back into the system and had the same problem.  Out of frustration I swapped out the patch cord, and the porblem disappeared.  With the 'intemitent' aspect of the problem I would have not imagined that the cable was the culprit. Now its the first thing I check when an issue comes up.

Have you tried cleaning all tube sockets, tube pins, fuse end caps and fuse holders?  If there are fuses on the PCBs, check with an ohmmeter to confirm that they have near zero resistance.  The resistance inside a fuse can occasionally creep up as the joints age.  Also, try cleaning the contacts on any detachable cables and ribbon headers inside the unit..