From PYLO–(at)–su.edu Fri Nov 3 11:01:37 CST 1995
Article: 2924 of rec.audio.tubes
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From: PYLO–(at)–su.edu (Ruth and Dale VanZile)
Newsgroups: rec.audio.tubes
Subject: Re: 5881’s for GTA-SE40; Tung-Sol vrs. Sovtek
Date: Thu, 2 Nov 1995 20:10:52
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In article <47bqhb$nj--(at)--ardcopy.ny.jpmorgan.com> lewi–(at)–pmorgan.com (Lewis King) writes:

>Ok, if I read this right, then:

> – the 6L6GC has higher power ratings than the 6L6GB
> – the 6L6GC has higher power ratings than the *original* Tung-Sol 5881
> – the 6L6GC has about the same or higher power ratings as the Sovtek 5881

Actually, the Sovtek 5881/6L6WGC is equivalent to a ruggedized version of a
6L6GC, which means that its ratings would be at least as good, if not the
20-30% better that the original 5881 was better than a 6L6GB. A friend of
mine near NYC has tested these with a high-voltage supply and found that they
will dissipate almost 42W before the plates start to glow. I’ve tested them
as high as 40W (approx. 500V–(at)–80mA) for red plate conditions in a darkened
room (when you can see even the smallest trace of red glow…..). Definately
not a regular 6L6GC. It can handle rather high voltages (I’ve heard rumors of
600VDC not being a problem as long as idle current keeps disspation below
specs…). The 5881 nomenclature for this tube is really misleading, as they
perform like a slightly-higher-transconductance version of a 7581A or
7027A…. Very hard to kill. I’ve been using a quartet at 500VDC (with a
healthy 45mA of idle current) in a musical instrument amp for at least a year
with no signs of weakening. No emmision burn on the glass (even when viewed
in front of a clean, white sheet of paper), no rattles, no bad sounds.
They’ve been pumping out 35W/channel all this time (small output transformers
& power supply…).

>The Sovtek 5881/6L6WGC’s more powerful than the Tung-Sol 5881/6L6WGB’s ?

Yes, very much so.

>(What is the meaning of the ‘W’ in 6L6WGB vrs. 6L6WGC? Isn’t that just
>a reference to the physical base?)

Nope. It means that the tube is “ruggedized” for military or similar service.

>Would any circuit changes (i.e. plate voltages) be advised or should I
>just pop them in without worry?

I’d be sure to check idle current, overall B+, and set bias when plugging in
the Tung-Sols. If they are safe in your amp’s circuit (not over the 22? W
dissipation rating or over the Vp-max figure from Tung-Sol’s literature), they
ought to sound really nice when the amp is adjusted to suti them….

Dutch