Help! My distortion sounds like a wounded animal!

Guess what! I got myself a DS 1 modded by Robert Keeley with Seeing Eye and Ultra modes! Also guess what - I can't make it sound any good!
This really blows. I know that the pedal should be used to 'drive' the tubes in my amp, but what exactly does this mean? Does it simply mean I have my amp on a clean channel and then the pedal provides all the distortion? Or that I put my amp on the dirty channel so it is already drivin and then use the pedal to push it further? How much involvement do the volume/tone controls on the guitar have in this? Why is it that this is the pedal that people like Satch and Vai use and they get a really thick beefy sound with it, whereas mine sounds really tinny and crap? Anyone who can give me AS MUCH INFO AS POSSIBLE on this will receive a virtual hug and the inner contentment that can only be gained from helping out a stoopid fool like me. Many thanks. P.S. My setup is an Ibanez JS 1200 (Satriani sig. model) into Keeley DS 1 into Peavey Classic 30 amp (all valve).

well, i think its better to keep the gain low, ive heard that they're not perfect for tube amps.

How do you have it set up? Are there any other pedals in the chain? If not, it should be guitar>pedal input >pedal output>amp input. Use it through the clean channel. If you want a fat sound, try turning the mids to 8+, and the bass 7+. Keep the treble at 5 for starters. Also mess around with your guitar tone knobs, and maybe your volume knobs to.

Your amp plays a big part too. Vintage sounds were somewhat trebly/thin compared to modern sounds. You might need to get a more modern amp.