• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Tomb Raider

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Hello guys. I´m working in a telecommunications company.
Yesterday, I was in a store place and I found a couple
of tubes. I decided to take a pair, ´cause they are
reeplacements of equipment that It was out of service a
couple of years ago...well...more than 10...I felt like Lara Croft...
Here a list of the tubes:
National: 5Y3GT, 6360A, 6CK6/EL83
Sylvania: 6F6GT, 6AK5/EF95
Phillips: EF91

A good mix, not??
Well, I was searching in the Web, ´cause I don´t have
any experience with tubes and I found only three are
used in audio applications:
5Y3GT,12AT7 and 6F6GT...Is it rigth???
5Y3GT is a rectifier
12AT7 is used in preamps
6F6GT is used in amps.
The others:
EF91 (RF applications), 6CK6 (Video), 6AK5 (HF amp),
6360A (???)

I want to make a good preamp and, if It´s possible, a
decent amplifier (I mean 30W... more or less)

Question: I was reading that is possible to use 12AT7 in
"replacement" of 12AX??? When I said replacement I mean
that is suitable for similar application... What are your
Question: Any idea of schematics of some of the tubes???
Something about 6F6GT??? I think that the "others"
are a litle more common...

Any comments and advices will be appreciate.
Thank you very much.
from Buenos Aires - Argentina
6F6 is a power pentode - a pair can deliver 15 watts or more. If there are four, it would be a start at a stereo amp. If there are two, a single ended stereo amp is a possibility - but only about four watts per channel. I have a little amp like this on my computer (12AX7 and 6AQ5s). If you want to build something, I can give some pointers.

12AT7 is lower gain, higher power than 12AX7 - makes a good driver tube as well as preamp. 6360 is a odd one - dual pentode for RF amp at 200 MHz - but it is specified for audio too - see http://frank.pocnet.net/sheets/133/6/6360.pdf
Thank you for your answer Tom.
In these days, I´ll start a design, in spite of I´m not specialized in tubes. Yesterday I was reading a lot and I think that It´s not so complicated. At leat I hope so...
Greetings and I´m sorry for my english...:) :)
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