Suggestion used tube amp between $1,500-2,000

Where can one get a Vac 160 for $1.5-$2k? 

Another vote for Quicksilver and there is always Rogue Audio to consider in this price range.  I do disagree slightly with people recommending higher power tube amps though.  That will depend on your room size.  My speakers are 90 db sensitive in a 14' x 19' room and I rarely exceed 5 wpc, it gets uncomfortably loud at that level.   I know this because I keep old amps with power meters around.  So what is the room size and how far is your listening position?

Regarding power requirements, I would add that in addition to room size, listening distance, and individual volume preferences, a very major variable is the dynamic range of the type of music that is listened to.  Dynamic range meaning the difference in volume between the loudest notes and the softest notes.

Many and probably most pop and rock recordings are compressed to dynamic ranges of less than 10 db, meaning that less than 10 times as much power is required to reproduce the loudest notes as is required to reproduce the softest notes.  While many recordings in other genres, such as classical symphonic music, can have dynamic ranges of 30, 40, or even 50 db. A 30 db dynamic range means that 1,000 times as much power is required for the loudest notes as for the softest notes. A 40 db dynamic range means that 10,000 times as much power is required for the loudest notes as for the softest notes.  And music having wide dynamic range will generally be played at levels such that brief dynamic peaks reach much higher volumes than the peaks of music that never gets much above its average level.

Which is one reason that like most recommendations for amplifier power that are provided by speaker manufacturers, SF's recommendation for the Venere 2.5 (40 to 250 watts) covers a very wide range.

Regards,
-- Al

The input impedance of the RM-200 is 30k via it's XLR inputs, I believe.

Thanks bdp24. But note that the LS7 preamp only provides unbalanced RCA outputs. And using an adapter to put the unbalanced signals into the amp’s XLR inputs would most likely still result in the LS7 seeing a 15K load, as the 30K figure most likely reflects the sum of the impedances of the two legs of each of the balanced inputs.

Regards,
-- Al