Tubes are a very important part of my sound. Obvious, 'cause my signal always passes a minimum of 13 preamp tubes and 8 power tubes. Where as with a "normal" guitar amplifierhead you should be happy if the signal passes the half of the tubes it does in my system. They give a rich and full sound and lot of dynamics plus a type of distortion that is not yet available in any other way. Not even with a the best modeling amps.
The Mesa/Boogie
Quad preamp uses 8 preamp tubes. I've just
switched my old blend of GE 5751's, RFT, Mullard and JJ tubes for NOS
70's Tesla E83CC. These are original Telefunken production and are as good
as it can get with tubes. The preamp never has sounded this good. The NOS
Tesla's have a very warm sound, wide frequency response and great detail.
Even at high gain settings you can hear clearly every note. Clean sounds
are very dynamic, rich sounding. Simply amazing. The GE 5751's in
combination with the RFT's was really nice, but it lacked some depth on
the clean channels. Also the dynamics have improved with the
Tesla/Telefunken tubes.
The Climax S3 preamp came stock with AEG ECC83 tubes, which are.... indeed Telefunken production!. Although most the tubes were still fine, I changed them all to Tesla E83CC. In the future I might experiment with some ECC81 or ECC82 tubes for the crunch channel to get a slightly different sound. But for now the Tesla E83CC's are mighty fine.
The Mesa/Boogie 395 poweramp uses 4 preamp tubes (JJ ECC83S) and 8
power tubes (JJ 6L6GC). The powertubes are closely matched by
Watford Valves
and specially selected for this amp. The preamp tubes all have balanced
sides, so are ideal as phase inverter. I wanted either JJ's or
Svetlana's, but because the guy who builds Diezel amps recommended them
(he uses these for all his amps, and they sound amazing), many Egnater amp
users were very happy with them and the owner of Watford Valves
preferred them as well for my type of use, I went with Tesla/JJ's.
Later I found out that they have better specs too. I really enjoy the
improvement over the stock Chinese power tubes. The sound is more relaxed
now, that's the best way to put it.
I also have a bias pot installed in the poweramp so the tubes could be biased correctly. The now run on arpox 85% of max rating, in stead of the cold fixed bias setting of Mesa which is aprox 60% of max rating. The difference was huge. The sound was a lot more powerful, nicer/rounder tone, great harmonics when overdriven, etc. I highly, highly recommend to anyone with an amp that has a cold or fixed bias to get it checked and setup right. It's a small fee to pay, but the sound is a lot better.
Although my
poweramp has an easy job to do - I mean 200 watts of tube power is a lot
if you only connect one 4x12" cabinet - I can now run it on half power
without any "problems". When I had the Chinese tubes, half power was not
an option.The sound became very harsh and undefined. It was really painful
to listen to. But now the sound just gets bigger when the powertubes are
saturated. Because I still enjoy a huge amount of tight low end in my
sound,
I run
my poweramp at full power. It is quite an expensive job to replace tube,
but it is well worth the sound. It has a headroom that's unbelievable and
the air pressure it delivers is overwhelming. I've heard 50 watt Marshalls
with the volume on 10 that deliver the same power as my setup with the
volume on 3.
The DigiTech GSP2101 uses 2 12AX7 tubes for the preamp section, but because I do not use the preamp anymore, I've placed stock JJ ECC83S in it. When I did use it as a preamp (long time ago) I used a Sovtek 12AX7WXT and a Mullard ECC82 (12AU7).