Preamp for a Dan D'Agostino S250MxV Amp

If you’re not getting the matching D’Agostino preamp and are considering tubes, then ARC Ref 6 or 6 SE should be on your list. Sonically superior to McIntosh C2700. VAC is also up there with ARC.

I think it would be a temp preamp while I save up for a DD preamp.   I figure McIntosh holds it's value pretty well?

And I would either sell the McIntosh after or possible move it into a secondary room.  

The Audio Research LS28SE would be closer in cost to the C2700.  

Do I need to investigate the output impedance of the preamp and the input impedance of the S250 which is 1M ohm?

LS28SE: OUTPUT IMPEDANCE: 600 ohms Balanced, 300 ohms SE Main (2), 20K ohms minimum load and 2000pF maximum capacitance.

C2700: Output Impedance 100 ohms Unbalanced 200 ohms Balanced

Both the ARC and the McIntosh will work.