Dan D’Agostino Master Audio Systems Upgrades its Momentum Amplifiers

Enriched by the process of creating its Relentless flagship amplification, Dan D’Agostino Master Audio Systems applies engineering lessons learnt in that process to its new Momentum MxV line.

The new S250 MxV stereo and M400 MxV monoblock amplifiers have received numerous enhancements derived from the Relentless über amplifiers. As a relevant physics-based morsel, MxV stands for Mass times Velocity, an equation which equals an object’s Momentum.

Starting with the Momentum S250 MxV stereo power amplifier, the company states there have been “advances in every area”. The S250 MxV introduces a new ‘ultra-quiet’ 1.8KVA output transformer which is said to be capable of 50% more output when compared to the previous model. The power supply also features a near-100,000 micro-farads capacitor bank with the resulting power output being 250 watts, 500 watts and 1000 watts into 8/4/2 ohms respectively. The new S250 MxV employs the same 69 MHz bipolar output transistors (which provide 10 times the current of the previous model) and the discrete fully complementary direct-coupled balanced configuration as its predecessor. Many circuit and layout refinements have come about directly from Relentless findings, with the input stage featuring a new circuit topology altogether. A new bias scheme provides increased high-bias into Class-A.


Similar advancement and rethinking has been applied to the Momentum M400 MxV. In fact, the new monoblock amplifiers use the same output transistors as the Relentless flagship. Each mono amplifier uses 26 bipolar transistors and the same 1.8KVA high-current output transformer and 100,000 micro-farad capacitor bank as the S250 MxV (with a stereo configuration using two of them, of course). As the model suggests, the M400 MxV is capable of outputting 400 watts, 800 watts and 1600 watts into 8/4/2 ohms loads respectively. Substantial circuit refinements and layout techniques have been implemented, as has the new biasing scheme.

The unique copper Venturi-style heat management system is continued in both models, with the extraordinary chassis aesthetic remaining the same as previous models. Each unit is entirely hand-built and tested in Dan D’Agostino Master Audio Systems’ facility in Arizona, USA. Because the new amplifiers employ the same chassis design, the company offers an upgrade path to full MxV specifications for owners of original Momentum amplifiers. The entire circuit is upgraded and a new meter is provided to reflect the increase in power (original Momentum amplifiers require the new meter).


The new Dan D’Agostino Master Audio Systems and the new S250 MxV and M400 MxV amplifiers are distributed around the country via Advance Audio Australia. Availability is via the importer’s established Australia-wide network of specialist audio retailers.

Dan D’Agostino Master Audio Systems S250 MxV and M400 MxV amplifiers
Price: S250 MxV AU$69,995 and M400 MxV $64,995 each

Australian Distributor: Advance Audio Australia
+61 2 9561 0799