I had a low level noise in my main system for a good while... couple of years. I thought it was an issue with a tonearm. Looked at finding someone to polish or replace bearings. Over time, the low level noise became more intrusive and sounded like a dirty volume pot in my Dodd pre... only randomly and without the volume being touched. But finally I desoldered and put in a new Alps. It was a pain in the ass, and fortunately Rich H was available to guide me to the correct replacement. But that wasn't it. And then
, I decided to replace the 6H30DR tube... success!!! For a day or two.
Time to call the pros. I talked with Charlie Cocci, who has most of the schematics for Dodd gear. We decided to replace a board, and Charlie had an extra on hand to send me. A week later it arrives. The unit is plugged in but the case is off and I start to look at the board. It's got a pin connection that I touch... and the noise appears. I wiggle it again, and the noise appears. I wiggle another pin connection, and the noise appears. I call Charlie, and after a liberal spray of Caig De Oxit and a good scrubbing with a set of brushes for tube sockets, the noise is gone.
A year or two has gone by, and all it really needed was to take the internal connectors loose, clean them, and put them back on.
This has been a hard lesson learned. Corrosion is insidious. Take the case off your gear occasionally and clean all contacts. It will be on my list of annual things to do.
