How the TS-9 changes its distortion/voicing from amp to amp is going to be very different. Same thing from guitar to guitar. Same thing for how you use the TS-9 in a low gain/high volume presence boost to boost the articulation/presence on a tube amp. Your TS-9 -could- have lost some of its gumption over the years from a cap leak or something, but unless it sees regular use like every day, odds are it hasn't. Especially if you just dug it up from a closet or something.