Nope. Not out of tube amps. I build and design my own stuff (yes, I know how the players are modded as well).
I find the modded CD63 too sluggish, too smooth and too sweet sounding. Might be great for vocals but not something I'd choose for rock/ 'eavy metal.
His Tocatta's are fairly neutral with a touch of boost on the low end. Yes, i do know what's used for the Tocatta's as well.
Well, not knowing what ancillaries you've used with the player I can't say why you would come to that conclusion. My findings are totally opposite and I use Krell amps with it (and they don't hide anything - warts and all). The player has been fast enough to scare the begeezus out of me on certain dynamic tracks. Granted, his preamp isn't as open or fast the Krells.
Not trying to take a swipe at you but why would you waste good money on a high end system only to listen to heavily processed music genres like rock and heavy metal? Genres that don't generally use minimalist recording techniques or acoustic instruments. It is like a waste of money as you can get the same results from lesser equipment.