an D’Agostino Master Audio Systems calls its new Momentum HD preamplifier ($40,000), "a major upgrade to the Momentum Preamplifier." The fully balanced Momentum HD incorporates advancements in the power supply, audio circuitry, and control sections, and owners of the preamp's previous version can upgrade to these new circuit enhancements for $7500. The Momentum HD's main power transformer is 33% larger than that used for the original Momentum preamplifier. The transformer, which remains housed in a separate chassis, features a unique winding technology, first employed in the Momentum M400 amplifier, that delivers greater power output from a transformer that occupies the same footprint. Internal circuitry filters RF noise from the AC power and compensates for asymmetric waveforms and DC. A completely new discrete differential FET input stage features two current sources per leg and an input impedance greater than 1 million ohms. This ultra-high input impedance isolates the input stage, and the entire audio signal path, from external variables. About this input stage, Dan D'Agostino says, "This new input stage was an engineering experiment that surprised us with the level of fine-grain detail and delicate musical shadings. The subtleties of voices were rendered with a lushness and richness that were simply unattainable previously." The Momentum HD's output stages operate at 36% higher voltage, in concert with the increased capability of the new power supply. Dan D'Agostino says, "The increased output voltage has opened up the dynamics on both the micro and macro levels. The speed of the dynamic contrasts jump[s] out on a visceral level." Also new are redesigned tone and volume-control circuits
that increase the range and precision of both. Finally, the Momentum HD's new remote
control uses Bluetooth technology to extend the usable range by a factor of five and
eliminate line-of-sight limitations inherent in IR remote controls. |
