Krell is Hard sounding and the will just make most Heavy metal annoying if you wanna good example of fast and heavy, fatigue is always the first word that comes to my mind, Wadia is far more deep and smooth, very in your face dynamic however, but My experiance is with the older true 16 bit machines, all newer 24/96's seem to carry some digital glare with them and this could be the issue with newer wadia's for all I know. Get a Wadia if you want the best Algorythm out there with the digimaster system and just have the analog stage upgraded. Also there are a few Metronome Players which are tube that are very nice on this site for around 1000.00, don't get caught in the hype.