The Momentum amplifier from Dan D’Agostino Master Audio Systems delivered magnificently on the initial design goals of formidable power and incomparable finesse from a compact chassis.
The driving force behind theMomentum M400 design, Dan D’Agostino, is constantly creating and revising his thoughts on circuit design and their implementations. What started as an engineering exercise resulted in an exciting new breakthrough that Dan felt compelled to include in the Momentum amplifier. These efforts have led to a substantial upgrade in the new Momentum M400.
The new M400 moniker gives clue to a major part of the upgrade. Power output has been increased to 400 Watts. This is up from the original 300 Watts. The backbone of the power increase is a new ultra-quiet 1,800VA linear transformer – a 20% increase in size from the original. Coupled to this larger power source is a new output stage design that includes a number of major enhancements.
Feeding every amplifier output stage is circuitry known as the driver section. In the new Momentum M400, this stage has been elevated to a fully complementary design. There are now individual transistors employed for the positive and negative halves of the musical signal. This change nearly doubles the current drive necessary to maximize the enhanced output stage that follows. The new output stage takes this increased drive to boost the open loop gain by the same factor of two. The result is a sound that is more authoritative, richer, and more expansive. It is almost hard to believe that improvements could be made to the original Momentum amplifier after one reviewer said, “No component has had such a profound effect on me…” but Dan has done it!
The Momentum M400 employs the same chassis as the Momentum with a small aesthetic design change to the copper feature on the faceplate sides. Additionally, the meter now displays a scale appropriate for the greater output.
With the Momentum M400, Dan D’Agostino has once again elevated the state of the art in amplifier design.