Robert S. said:
After glancing over the manual I am optimistic that there is a solution and that you wil get useable tone from that amp. At first I was worried that Peavey might have used a SS preamp in those and their marketing on that amp boasts an "all tube" power section but their preamp descriptions made me wonder. The manual lists 3 12ax7s though so that part is all good.
The other thing that sent up flags was the EXF prefix. Peavey, Crate and other makers have historically put effects into their lower end amps to make them sell better and to cover up marginal tone. Peaveys marketing for this amp statiing that this amp obviates (fancy word, huh) the need for pedals but its been my experience that DSP effects in an amp usually obviates the need for the amp itself. Once again, the 12ax7s and 6L6s ease my worries a bit.
Strip away all the extras and you have a 40 watt tube combo and thats not a bad starting point. The trick for you now is to figure out what all the buttons and knobs actually do to your tone and to dial in your tone. That amp has active tone stacks and EQing as well as quite a bit of preamp gain coupled with different boosts and shifts. You really need to remove or reduce alot of that gain at first and find the amps natural tone.
The harder you kick the bee hive, the louder the bees will buzz. Your amp is the same way. The more gain you add to your signal the more it will buzz. Graininess in your tone is most likely caused by you and your excitement over a new amp. "There is a button, push it - there is a knob, turn it" and make it go zoom thinking is common but often fatal to tone. With high gain amps less is often more and learning that is a hard lesson. Remember that all those active controls are meant for shaping your tone and with a 15 db boost available in multiple places you really have to go light on the controls or you will push your amp into ratty, harsh tones.
Instead of finding out how much torque that amp has, (I know thats why you bought it) try the opposite. Go to the clean channel and find out how warm and round you can make the tone. Set the tone controls to 12 oclock (no boost and no reduction), turn off any resonance, boosts, EQing or anything else that adds to the basic circuit. Your tone is too grainy now so find out what you can do with its most basic tone. From there you can turn one knob at a time and see its effect on the tone of the amp. Always return that knob to its original position before turning another and soon you'll see what some of the possibilities are.
From there start adding gain slowly and experiment getting a warm clip from the amp. This will sound like a warm, light crunch and will also sound more bluesy than metal. The distortion will increase the harder you play the guitar. Once again experiment with the controls one at a time to see how the amp responds.
Keep adding gain a little at a time and keep experimenting. As soon as your tone starts to get harsh find out why. That won't be easy as you have all sorts of control available but it will be easier doing it this way than it will be to turn everything on and to 10 and then start subtracting.
