Tube preamp.

[Bill Layer]

  Hi,

Eric sent me a rather sexy (and very simple) tube preamp
uses 3 tubes for stereo, one rectifier and two 6sn7GTs.
If eric says its ok, I can scan in the the article and mail it
to those concerned, Eric?

If this is the circuit I'm guessing, it has two stages, the first being 
direct-coupled to the second. The output is a cathode-follower, for lower 
Zout. In any event, the 6SN7 is a tube so musical, that it is hard to build 
a bad sounding device with it. You'll notice that the front ends of ALL 
current Atma-Sphere amplifiers use the 6SN7 exclusively for both voltage 
amplification, and current drive for the output section. The line section 
of all current Atma-Sphere preamplifiers use the 6SN7 as the output tube 
(line driver) but in the Circlotron configuration...

Using the Circlotron at the output allows the preamp to directly couple the 
6SN7s to the line, without any DC offset issues.. This eliminates the need 
for an output capacitor or transformer (ditto for the power amps).

What I'm saying is, if Eric offers a 6SN7 design, it would be hard to go 
wrong building it. If you are looking for a load of parts, try and find a 
Hammond S series chord organ. They are worthless, but have about 28 6SN7 in 
each chassis.



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|      "The" Bill Layer - Frogtown, Minnesota. U.S.A.      |
| Vacuum tubes, Analog, Motorcycles and Other Alternatives |
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