Dynaco-Doctor Forum

Mark III odd hum after warming up

207.38.43.30

Howdy folks,

Have a hum question for you. I have a set of Mark III's that I've been using for a while now. They have been driving a set of ACI Sapphire XL's up until this weekend as I picked up a set of Klipsch Fortes. I don't hear any appreciate hum upon first firing the amps up and on one, it stays very quite even after a few hours of listening. The other hum starts to build up a hum which sounds like a little 60Hz line hum on top of higher frequency hum that may ebb and flow in and out. At its loudest I can slightly hear it while at the listening position. I haven't had a chance to swap output/rectifier tubes, but did swap the 6CG7 driver tube of the Triode Electronics driver board and this did reduce the noise a little bit, but not all that much. Something else I think is going on. As I said, the other amp is totally quiet and I build both at the same time and should be the same throughout. The weird thing is that it takes a while for this to show up.

Any thoughts?

Cheers!

Follow Ups:

RE: Mark III odd hum after warming up - Joe Curcio 08:34:52 09/15/09 (2)
- RE: Mark III odd hum after warming up - sford@altair.com 23:07:15 09/16/09 (1)
  - RE: Mark III odd hum after warming up - Japhy 11:05:54 09/21/09 (0)

Post a Followup:

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.

To view your new posting or follow-up, click on the RELOAD or REFRESH button on your browser.