I would suggest th Adcom 750. I think it was GP 750. Very simple Pass design. I had one for a whil, loved it then went with a dac with a volume control. I have the aleph 1.2's. Good luck
Matching preamp for Pass Labs Aleph 5
Looking to match a preamp with the Pass Labs Aleph 5 (60W). My CD is a Naim CD5,cables are Cardas,and speakers are Audio Physic TempoIIs(a little bass shy and bright). Something active or tubed with warmth and detail. Tried a Pass Aleph L passive but flat in the lows among other things. A tube preamp must have higher output impedance since the Aleph 5's input impedance is very low (14 Ohms). Thanks