Home Tubes Asylum

Questions about tubes and gear that glows. FAQ

Trouble with some Russian 6N3CE on MC240

I would like some input from the experts on a tube/amp issue I'm having. I bought a nice quad of the Russian 6N3CE tubes from Jim McShane about three years ago. They've worked great and I've had no issue until a couple days ago.

On my McIntosh MC240 (fully restored), I started getting a popping sound through one channel. I turned off gear to see what was causing it and it seemed to be my subwoofer. But I shut things down and let it sit.

Next day I fire it up and it all plays great for 3 or 4 hours with no issues.

Next day the popping is immediately back and it appears to be my amp. On close inspection I can see the two power tubes nearest the controls are flashing blue in time with the popping. The blue flash is on the plates I think. Because it's two of the power tubes flashing and one didn't just spectacularly die, I'm unsure if this a failing tube or if the tube pair isn't being feed proper power.

So now I'm wondering if I should just try another pair of tubes or pull it up to the test bench and start measuring voltages? What typically causes the plates to flash? Failing tube, surging voltage or failing cap somewhere? TIA.


This post is made possible by the generous support of people like you and our sponsors:
  Schiit Audio  


Topic - Trouble with some Russian 6N3CE on MC240 - tommytube 11:37:03 12/16/14 (2)

FAQ

Post a Message!

Forgot Password?
Moniker (Username):
Password (Optional):
  Remember my Moniker & Password  (What's this?)    Eat Me
E-Mail (Optional):
Subject:
Message:   (Posts are subject to Content Rules)
Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:  Automagically notify you when someone responds.