Help: Unidentified high-pitch sound


Hello---I'm hoping someone can help me identify the possible source of a intermittant high-pitch sound coming from my left speaker. So first of all, here's my system:
-VPI TT
-Modwright SWL 9.0 AE preamp
-Bel Canto REF500s amp
-Marantz 8006 CDP/streamer
-Dynaudio Special 40s
-WyWires ICs

My system is only about a year old old and up until a week ago, everything has been just fine---beautiful music. I usually hear the tubes warming up for the first couple of mins with a little 'ping' sound. But then I noticed a slight but audible high-pitched sound coming from my left speaker---nothing on the right. I had been listening to the streamer when this happened. So I switched the sources on the preamp and still noticed it no matter what source I picked. But sometimes it did disappear while I was switching the source. I don't notice it when the music is playing---but when the song stops, I hear it. Then, a couple days ago, I was turning off my system and noticed it disappeared when I turned off the Bel Canto. So is the source the amp or the preamp or something else? Thanks so much for any advice.
bluorion

Showing 2 responses by uberwaltz

If it does move with the preamp output swap you could then go further.
Open up the preamp( powered down of course) and swap the tubes themselves L and R.
While in there you might possibly find one tube was loose in its socket.
Anything is possible but I would definitely start at the Modwright if it was myself.
Good luck.
My first point of suspicion would be the Modwright preamp with a tube going bad.
I would start there, swap the main pre output L & R to the power amp and see if it moves with it.
If so it is possible a new pair of tubes are the order of the day.

Good luck and stay safe