Mic Kaczmarczik's TubeInformation - The Blue Guitar
Mic Kaczmarczik's TubeInformation - The Blue Guitar
Mic Kaczmarczik's TubeInformation - The Blue Guitar
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
From Dr.Distortion@bbs.mhv.net Sat Jan 20 15:41:53 CST 1996<br />
Article: 8284 of alt.guitar.amps<br />
Path: geraldo.cc.utexas.edu!cs.utexas.edu!news.sprintlink.net!mhv.net!bbs.mhv.net!Dr.Distortion<br />
From: Dr.Distortion@bbs.mhv.net (Dr Distortion)<br />
Newsgroups: alt.guitar.amps<br />
Subject: Re: 6L6 and other tubes<br />
Date: 18 Jan 1996 17:25:54 GMT<br />
Organization: MHVNet, the Mid Hudson Valley's Internet connection<br />
Lines: 43<br />
Message-ID: <br />
References:<br />
Reply-To: Dr.Distortion@bbs.mhv.net<br />
NNTP-Posting-Host: csbh.mhv.net<br />
X-Newsreader: TIN [version 1.2 PL2]<br />
Tormod Eikill (teikill@telepost.no) wrote:<br />
: I thought that the only tubes I could use on the output for my Twin was<br />
: the 6L6 series. So when you're talking about "5881" or any other number, I<br />
: don't understand shit. What is all this?<br />
Between the varieties of 6L6 types available and the fact that certain<br />
suppliers like to play fast and loose with the numbering system, it's<br />
natural that a lot of confusion would result. Here's a very brief<br />
overview of the 6L6 family of beam power tubes:<br />
6L6: <strong>The</strong> original metal-cased version. Not recommended for most guitar amps.<br />
6L6G, 6L6GB: <strong>The</strong> early glass versions. <strong>The</strong>se are not rated for the kind of<br />
service they would see in most modern guitar amps, although they are<br />
found in some old amps from the '50s.<br />
5881 (Old): This is a "ruggedized" military version of the 6L6GB. Again,<br />
they're not rated for the kind of plate voltages and dissipation you see<br />
in more modern amps, but they're great for old Fender Tweeds and the like.<br />
Many folks (myself included) have used 5881s with no problems in<br />
Blackface and Silverface amps, but they are being run beyond their<br />
ratings in such cases.<br />
6L6GC: This is the most modern version of the 6L6, and the one around<br />
which all the '60s and later Fenders were designed. Ratings are higher<br />
than the older versions.<br />
7581, 6L6WGC, etc.: Ruggedized military 6L6GCs. A stock of Philips 7581s<br />
has become available on the market recently, and the "word on the street"<br />
is that they're very good tubes.<br />
5881 (New): Sovtek/New Sensor and some other suppliers have seen fit to<br />
revive the 5881 designation for their new 6L6GCs. <strong>The</strong>se should not be<br />
confused with the old 5881s--for instance, Tung-Sols. <strong>The</strong> Russian 5881s<br />
are good reliable tubes, the best 6L6 type being manufactured right now.<br />
<strong>The</strong>y have been used succesfully in very tough applications, even as<br />
quasi-substitutes for 7027s. In my opinion, this is the best tube to use<br />
in just about all 6L6-based guitar amps.<br />
One thing I should mention is that the new 5881 usually biases up at a<br />
less-negative grid voltage than the other 6L6 types, so you cannot simply<br />
plug a pair into your old Fender and get optimum results. <strong>The</strong> amp should<br />
be rebiased by a competent tech.<br />
Back to JT30 Home