Be100 tube set

Yes any preamp tube will work but not all can work in V1 and v2 because of microphonics. Right now we are using EH el34 tubes as they seem to be the most reliable.. JJ is awful at the moment and the Chinese el34 has a tendency to just up and short.
 
thanks. got some new tungs and sovtek lps.
gonna try them out only because i dont really know how used the ars tubes are. i purchased the amp used.
thanks again
 
EL34EH have been the best so far and they sound great, "Two Sets of T.A.D. power tubes were Bad".

Tung-Sol 12AX7 (V1 / V2) Ruby 12AX7 HG (V3 / V4) these preamp tubes have worked out the best.
 
RACKSYSTEMS":2vhzdmni said:
Yes any preamp tube will work but not all can work in V1 and v2 because of microphonics. Right now we are using EH el34 tubes as they seem to be the most reliable.. JJ is awful at the moment and the Chinese el34 has a tendency to just up and short.

does v3 and v4 need to be chinese tubes??
 
If you want some real magic, find some pre-war EI 12ax7s for V1 and V2. Harmonic complexity and richness. So very good.
 
donho":mw4frv9v said:
RACKSYSTEMS":mw4frv9v said:
Yes any preamp tube will work but not all can work in V1 and v2 because of microphonics. Right now we are using EH el34 tubes as they seem to be the most reliable.. JJ is awful at the moment and the Chinese el34 has a tendency to just up and short.

does v3 and v4 need to be chinese tubes??
Some people ( including me ) have had issues using any of the New Sensor 12ax7's with the spiral filaments in the cathode follower position (V3 in the BE100) of various amps. These would be the Tung-Sol, Mullard re-issue, EH and Sovtek 12ax7's. The issues are bad hum and extremely short life, and it has to do with the maximum heater to cathode voltage spec of those spiral filament tubes.

Any of the chinese 12ax7 variants or JJ 12ax7's would be your safest bet for new production tubes in V3.
V4 is the phase inverter, and any 12ax7 should be fine here. A lot of guys like the Sovtek LPS for phase inverters.

And as Dave said, V1 and V2 need high quality, low microphonic tubes, so best to buy screened and tested tubes from someone like ValveQueen for these positions. Or NOS if you have the budget.

Edit: the reference to the Sovtek 12ax7's not being used in the cathode follower position only applies to the LPS variant. The 12ax7WA / WB / WC versions should be OK if you choose to use them in V3.
 
Rdodson":19xq2ucs said:
If you want some real magic, find some pre-war EI 12ax7s for V1 and V2. Harmonic complexity and richness. So very good.
I agree. EI are my favorite tube for V1 in a Marshall type circuit.
 
Rdodson":3vi2x3i7 said:
If you want some real magic, find some pre-war EI 12ax7s for V1 and V2. Harmonic complexity and richness. So very good.

I have found that an Ei 12AX7 in the PI slot (matched or not) makes my amp sound glorious!
 
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