Tubes Asylum

One tube of a quad failing

24.66.136.242

2chblast

I have an Eico Hf-81 which has a matched quad of EH EL-84 output tubes. One tube is faltering, testing about 15% weaker. Do I need to replace all 4 tubes? Or could I swap in one new tube

Follow Ups:

RE: One tube of a quad failing - tubemaze 03:58:36 08/09/20 (1)
15% is a major mismatch, especially if you can't bias it. If you swap one tube, it will likely be strong then others and create a disbalance again. How old are the tubes?

If you want to learn more about matching, check this out: https://tubemaze.info/tube-matching-101/
- RE: One tube of a quad failing - 2chblast 07:29:26 08/09/20 (0)
  This set has been going strong for 5 years. The tubes are used with Pearl tube coolers that extend the usable lifetime. I will order a new set.
RE: One tube of a quad failing - airtime 18:15:38 08/08/20 (0)
If that was a quad set going in then I'm pretty sure the others aren't that far behind it.

If you don't have individual bias pots, which yours doesn't, than enjoying a new set of tubes is in your future.

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.

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

VH Audio