Dan D’Agostino Momentum S250 MxV Stereo Amplifier

The Momentum S250 MxV is the single-chassis stereo expression of the Momentum program — the same fully complementary Class-A / Class-A/AB topology and copper-heatsink construction as the M400 MxV monoblocks, in a form that puts both channels in one chassis. The MxV revision brings the current Momentum refinements into the S250, so the choice between it and the monoblocks is a choice of configuration, not of generation.

What the single chassis buys is exactly what it appears to: one position in the rack instead of two, one power connection, a simpler system — without leaving the Momentum program or its construction standard. The machined aluminum, the copper heatsinks, and the signature meter are all present; the engineering intent is identical.

The honest way to choose between the S250 MxV and a pair of M400 MxV monoblocks is to start from the loudspeaker rather than the amplifier: its sensitivity, its impedance behavior, and the room it plays in decide how much amplifier the system actually needs. For a great many serious systems, the S250 MxV is not the compromise — it is the correct answer.

Momentum electronics run daily in both showrooms, on Wilson loudspeakers from the Alexia V down to the TuneTot, which means the comparison that matters — this amplifier, on a loudspeaker like yours — can be set up rather than speculated about. Tell us what it will drive, and we will build the audition around that question.