taken from http://www.peavey.com/assets//literature/r...ws/00575450.pdf
JAMES BROWN ON THE PEAVEY JSX
As Peavey’s Instrument Amplifier Engineering Manager, James Brown has a tube-amp design
résumé that includes the Classic 50, Rockmaster preamp, Triumph, VTM and Ultra series amps,
the 5150 (co-designed with Eddie Van Halen), and the Triple XXX. Brown worked closely with Joe
Satriani during the JSX’s development, and here he explains how the amp came together. —TB

“Working with Joe was really easy because he was very clear about what he wanted,” says Brown. “He liked the Triple XXX’s Clean and Crunch channels, so we decided to use that amp as the basic platform for the JSX. We spent a lot of time tweaking the Clean channel. I slid the midrange center frequency down a little bit, modified the channel’s brightness, and for the Treble control, I used an audio-taper pot—which turns up more gradually than linear-taper pots— to obtain a more vintage amp response. And because the JSX has three channels, I could fully
optimize its Clean channel for a clear, open sound. You can beat on the JSX’s Clean channel pretty hard without it distorting, and that helps it work well with pedals.

“Joe thought the Triple XXX’s Crunch channel had a really good lead tone, so that became the basis for the JSX’s Ultra channel. To improve articulation, I reduced low end in the preamp— which can be restored with the Fat switch, although it’s done in a slightly different fashion for a tighter attack—and I also reduced the gain because Joe thought the channel sounded a little
too compressed. We experimented with different amounts of gain and midrange to get a screaming lead sound that was also articulate and punchy.
“Joe really dug the lead channel of our Classic 50 for in-between sounds, so I modified the JSX’s Crunch channel to sound more like the Classic 50. This involved reducing the gain significantly, and I also had to tweak the Crunch channel’s active EQ to more closely match the limited range of the Classic 50’s passive EQ.

A cool thing about the JSX is that if you set every knob
to 5 on all three channels—meaning you have every knob pointing straight-up— and crank the bass on the two distortion channels, you’ll get a tone that’s very similar to Joe’s.

Have you tried that?

So bass, mid and treble on the clean, crunch and ultra all to five,
And the bass at max on crunch and Ultra?

hm....

It sounds pretty good to me.

also what Joe mentions, if you raise the channel volume, and lower the master volume you get modern amp tone.

if you do the reverse, you get a classic tone break up.

Cool, it's too bad that James Brown left Peavey, I hope that it does not negatively impact the JSX lineup (or any future additions).

Cool post!

And yes, the sound is somehow different but I still like to add a lot of resonance and some presence to make it more punchy :)

it was helpful..thanks