coop_301
I use a passive pre-amp ( attenuator and input selector ) with an all tube phone preamp and CD player powered by a McCormack DNA-250 without the need for more gain from a powered preamp .
Your Mark Levinson amp has more than enough power to forgo a powered preamp , if you go back at least 40 pages back you'll read about another Thiel / Spectal digital only owner asking the same question .
The question is do you want any other features that preamps offer ?