Mk III Bias Loss on One Tube

Dynaco-Doctor Forum

Welcome! Need support, you got it. Or share your ideas and experiences.

I have a Mk III that has developed an issue, so looking for a little help.

On power up, the bias goes up properly then, after 1-2 minute warmup, I lose about 1/3 of the bias when measured via the power/preamp socket.

I put bias sockets under the KT88s, and found that when the bias drops I completely lose plate current to V1 (the KT88 nearest the edge) and the plate current to V2 goes up as a result.

Anyone know what may be causing that?

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

The Cable Cooker

Topic - Mk III Bias Loss on One Tube - baileyler 11:30:33 10/30/14 (3)

RE: Mk III Bias Loss on One Tube - petercapo 12:28:23 10/30/14 (2)

RE: Mk III Bias Loss on One Tube - baileyler 13:36:34 10/30/14 (1)

RE: Mk III Bias Loss on One Tube - petercapo 15:48:11 10/30/14 (0)

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.