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Topic: Preamp Tubes |
Bill Crook
From:
Goodlettsville, TN , Spending my kid's inheritance
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Posted 30 Jan 2001 10:08 pm |
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| Can someone explain the difference to me between Sovtek, Fender, and Groove Tube |
1) Quality !!
2) price
3) MTBF
4) avalability (sp?)
We must keep in mind now-a-days, that no small consumer type tubes are made here in the U.S.A. now. 99.9 % are off-shore products,made with various degree of care in manufacturing and quality of medals used. The "Mu" of a tube is a good ruler to gauge a tube. (12AX7,12AU7,12AT7,etc,etc) However, these Mu number are often not in cluded in the tube carton, so how good one brand over another tube is, is at best, a lesson learned by experience.
The days of the RCA, G.E., Slyvannia and other major tube giants here in the U.S.A. was killed with the advent of the "solid state" device. There is No profit in tubes for the big dogs,so they sold the manufacturing machinery off shore to Russia, Tiwan,Korea and them places where labor is about 1/3 of our mim wage requirments (per month)
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Cliff Swanson
From:
Raleigh, NC
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Posted 31 Jan 2001 4:29 am
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I'm not sure whether your question relates to the difference between the brands or the actual performance characteristics of the tubes. Considering the tubes themselves, a 12AX7 of any brand should have higher gain characteristics than a 12AT7 of any brand. The tubes are direct fit replacements for each other, and, because they are also relatively inexpensive, this makes it easy to swap them out and experiment with the resulting tone/amp performance until you find a sound you like with your guitar and amp.
Hope this helps,
cat |
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Len Amaral
From:
Rehoboth,MA 02769
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Posted 31 Jan 2001 7:17 am
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If you think of a 12ax7a as having the most gain 100% of all the common preamp tubes used in amplifiers, a 12at7 will have about 70% of the gain of the 12ax7a and a 12au7 will have about 40% of the gain of a 12ax7a preamp tube. However, Sovtek has different gain 12ax7 prteamp tubes such as:
12ax7WA
12ax7WB
12ax7WXT
I also believe they have several other models
of the 12ax7.
Most amps that have a tube driven reverb will not use a 12ax7 preamp tube because it's too hot and will opt for a 12at7. The driver tube in a Fender amp will usually be a 12at7 also. |
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Jay Ganz
From:
Out Behind The Barn
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Posted 31 Jan 2001 8:13 am
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Well, since the tubes these days are of
varied quality, some of the companies who
sell them under their own name claim to
sort through them. They supposedly test 'em
out and reject the noisy (or weaker) tubes
before they stick their name on 'em.
The Sovteks are alright, but their new ones
under the Electro-Harmonix name are supposed to be made with the same characteristics as the old classics.
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Bobby Lee
From:
Cloverdale, California, USA
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Posted 31 Jan 2001 8:52 am
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| When I worked at Mesa/Boogie (1980-85), all of the tubes were tested for proper gain, low noise and low microphonics. Mesa developed special equipment for testing tubes in house, and the person doing the testing actually listens to the tube as well as seeing it on a scope. Tubes from some manufacturers would have a lot more "rejects" than others. At the time, the Chinese tubes were the best. |
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Scott Swartz
From:
St. Louis, MO
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Posted 1 Feb 2001 7:58 am
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New Sensor/Sovtek, Fender, and Groove Tubes are all getting the tubes from the same place. There are only a few factories currently making 12AX7s, located in either Russia (Sovtek, Svetlana), Czechoslovakia (Tesla, JJ Brand), or Serbia (EI). Groove Tubes charges a premium because supposedly they "sort" the tubes, and weed out the microphonic ones, etc, but exactly what you are getting for the extra money is a question. You can sort them yourself if you take your amp to the music store and try them out on the spot - just put them in and tap on them to check for microphonics.
Here are a couple of links to vendors of current manufacture and also NOS tubes.
http://www.tubesandmore.com/
http://www.angela.com
http://www.triodeel.com/
Angela Instruments in particular tests them in an amp and charges a lot less than Groove Tubes, but of course Groove Tubes paints a nice logo on them 
You will see on these sites that the good old US made tubes are still available, you just have to pay more.
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Jay Ganz
From:
Out Behind The Barn
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Posted 1 Feb 2001 8:06 am
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.....and if you're really lookin' for
premium tone, you gotta check out either
the "Mullard" brand tubes from Gt.Britain, or
the "Telefunken" ones from West Germany.
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Rodney Shuffler
From:
Montgomery, Texas USA (Home of the Bears)
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Posted 1 Feb 2001 8:36 am
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Mike at KCA NOS Tubes carries the Mullard (I use 'em in my Pro Reverb) and Telefunken tubes as well as many others.
Rod
------------------
Emmons S-10 P/P
[This message was edited by Rodney Shuffler on 01 February 2001 at 08:41 AM.] |
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Mark Ardito
From:
Chicago, IL, USA
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Posted 2 Feb 2001 9:28 pm
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You should be able to find some tubes called 'new old stock'. You should DEFINITELY check out Telefunken. I have replaced tubes in some old Neumann microphones and they used to be manufactured by the Telefunken company, so if you can find these tubes PICK THEM UP!!! They sound far superior to other brands.
Marcus
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Sage
From:
Boulder, Colorado
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Posted 3 Feb 2001 8:34 am
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| I have Mesa/Boogie tubes, and I'm glad I paid them to sort them out and test them. They're right on. |
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