po_sab said:
Hi
It's my first post.
I have a Mesa Boogie triple Rectifier since 2005, but I just realized that I don't have the 6 12AX7 tubes in the amp.
Are they really useful? I mean, what are they use to?
Because I want to replace all of my tubes, and if I they are not necessary, I may not buy them.
And by the way if you have any suggestions what tubes to buy...
thank you
Welcome to The Board.
Rampage is correct, if there were not any (12AX7) tubes in your preamp your amp would not produce sound, and they are located under the metal "cans" as described.
There are five (5) 12AX7 tubes in the Triple Recto, not 6. Their individual functions are described in your amp's owners manual.
If the amp is not making any strange noises, like whooshing, uncontrollable squeal or metallic ringing sounds, clicking or popping, I would just leave them alone, with the exception of maybe the Phase Inverter tube (V5). Preamp tubes can last a very, very long time.
As far as your power tubes (6L6GC) if they are the original at 6 years old yes, change them. For the most trouble free tube swap I would recommend using new Mesa STR-440 6L6GC replacements. Keep the old set as spares.
If you are a little educated on power tube operation, or have a vendor you can trust, you can try other brands of 6L6GC's or EL34's. However,
THEY MUST BE SELECTED TO OPERATE IN A MESA AMP. Mesa selects tubes that will operate properly at the bias specs of the amp, and your vendor must do the same.
Some good powertube tube brands are the SED =C= (winged C), JJ Electronics, Ruby, Tung-Sol, TAD, Groove Tubes & Sovtek.
My favorite 6L6GC for the Recto's is the SED =C= SV6L6GC.
Dom