re-tubing a twin

Hey all.. i have recently acquired one of fender's "professional series tube amp". Its "The Twin".... i beleive its one of the later versions of a the dreaded red-knob series.. but this one is later with black knobs.. im judging it to be from the early/mid 90's. Anyway... i played it out last night for the first time and i noticed that when i really called on it that it broke up and distorted quit easily.. granted i was playing through both channels and both vol. settings on like 8. Anyway... i want a MUCH CLEANER sound out of it. Here's what the amp calls for : 4 6l6's, 2 12ax7a's, 5 12ax7wa's, 1 12at7.... can anyone suggest tubes to use AND OR explain what the difference is between 12ax7/12ax7a/12ax7wa is? Im looking for the lowest distortion tubes i can find..... i was thinking svetlana 6l6gc's for power but havent decided on preamp tubes yet.... help

thanks in advance,
jerry

but amp seetings around 8 on volume...even on a Twin means slightly compressed Distortion imho. How could you stand it in front of it? The Super Amp I used to play from this era did the same at 7 (Even the Drummer left the rehearsel when I did that). The Twin has a selectable output if I remember it right. (25W or 100W). What did you choose. It also depends on your pickups. 8 with a Duncan Distortion HB is more than best! All my amps start to distort around 5 (SF & BF), my SFVR even at low 4. New tubes will give you some headroom (but do not expect much if the old ones are not damaged) and will brighten up the sound a bit. I chose Electro Harmonix for my amps. Very good value for money and of course sound.

The preamp tubes (unless one is defective) aren't really going to do much to clean up the sound. Same with the power tubes, unless one/all are weak.

For a cleaner sound with that amp there are two mail things to look at IMO - 1) bias settings, and 2) speakers.

If the amp is biased a bit on the cold side it will help clean it up - It may take a tech to do it (I'm not real familiar with these later models). And speakers will make a huge difference - something like Weber California-series 12's will really add some headroom and punch.

But - if you're having to turn that amp up to "8", something seems wrong - either the amp needs service, or the whole band is far too loud. That's a blistering SPL - hope you're using ear proection.

In addition to the above, a 5751 in the first position preamp tube might help clean things up. As far as power tubes, the cleanest ones you can buy are NOS JAN Phillips 7581A's.. You can get a pair for $50 from a guy on the WeberVST Forum..

If you don't need the distortion channel, you should consider unloading the amp and picking up a used 68-76 silverface twin.. And if those aren't clean enough, a later ultralinear 135w model might be the ticket..

Mike

I play a Twin pretty loud and they should not be squeaky clean at that volume. I agree with Mike on getting a quad of 7581's, but volume on 8, even these tubes will sound a little compressed.