Dan D'Agostino Master Audio Systems Momentum line preamplifier
Bling that Sings
You may find the looks of the Momentum preamplifier, from Dan D'Agostino Master Audio Systems, breathtaking or way over the topit's a matter of taste. To me, the Momentum ($32,000) is among the most beautiful pieces of audio gear I've ever seen or touched. The large, circular, protruding meter indicates volume level (on the Momentum power amplifier, this meter indicates the power-output level), set with a large, knurled, smoothly rotating ring that surrounds the meter.
The operating system has been carefully and elegantly conceived. To the left of the volume indicator, two rows of three pushbuttons each select among the inputs. When selected, the buttons in each row glow, from left to right, blue, red, or green. Below these are two more buttons: one is an On/Standby toggle; the other engages the tone controls, which are to the right of the volume indicator.
Those functions are repeated on the unilluminated backlit remote control. Circular and palm-sized, the remote also has buttons for Mute, Phase (polarity inversion), and Balance. When you push the Balance button, the Volume + and buttons become balance controls, the retro-styled green "magic eye" LED is dimmed, and the volume needle now serves as a balance indicator.
Push Mute and the green LED blinks. Pushing the Tone button on the Momentum or its remote illuminates, in neutral white, the front-panel Tone button and the eyebrow windows above the Treble and Bass knobs. Push Phase and the green-illuminated meter window glows pink.
D'Agostino includes a hefty and attractive auxiliary infrared receiver that can be used if a cabinet door blocks the front panel's built-in receiver, or if there's no clear line of sight between the front panel and your listening position. I can't imagine anyone buying such a gorgeous piece of audio jewelry and hiding it behind a door, but if you do, you need to provide adequate ventilation: The Momentum runs warm.
The six inputs represented on the front panel are labeled Server, Radio, DAC, Phono, Dock, and Theater. Just in case you missed it: There's an input labeled Phono, but not one labeled CD. Of course, you can use all but the Theater input for whatever kind of line-level source you wish. The Theater input is a unity-gain pass-through. When you select it, the volume meter pegs. Select another input and it automatically reverts to "0." This is a useful feature if you combine your audio system with your home theater. Otherwise, it's a wasted input.
While the Momentum's manual claims that the volume level automatically resets to minimum when you switch inputs, that feature stopped working at some point during the review period. Because of that, switching between inputs produced through the speakers a low-level tick.
The Momentum is shipped in a snazzy, wheeled Pelican road case with a presentation befitting a $32,000 piece of exquisitely finished kit.
The input labels on the front panel are not illuminated, and in certain lighting conditions were difficult to read. The circular remote's relatively small buttons are arrayed in four horizontal rows. From the top: Server, Balance, Radio; below that are the DAC, Phase, On/Off, Tone, and Phono buttons; then buttons for Theater, Mute, DOC; and, at bottom, Volume +/. A tiny red LED between the g and o in the Dan D'Agostino Master Audio Systems logo on the faceplate flashes when you push any button. The remote is easiest to use when it's sitting on a coffee table or other surface. Otherwise, unless you have long fingers, you need two hands: one to hold the remote, the other to punch buttons.
The fully balanced Momentum has only XLR inputs (six pairs) and outputs (two). There's no Tape Out or Tape Loop functionif you want to digitize your record collection, for instance, you have to use the second output, which is also associated with the volume control. That can be useful if your A/D converter lacks a volume control, but it also can require you to shut your amplifiers off to avoid ear-splitting volume possibly needed to achieve sufficient output. With level monitoring available via most computer recording programs, this turned out to be not as big a problem as I at first feared it might be.
The rear panel also has 12V trigger outputs, as well as 3.5mm and RS-232 inputs for remote-control/home-automation systems. But my home is not a "smart" home, and I didn't use these for this review.
The Momentum looks like a single-box design but is actually a two-boxer. The control and audio chassis, machined from a solid block of aluminum, sits on four aluminum cones whose points rest in indentations machined into the tops of the corner columns of the thin, curvaceous, satiny-finished power supply. The power supply sits on four soft isolation feet. The Momentum and power supply are electrically connected via a multi-pin umbilical, and together weigh a hefty 75 lbs. The combination of the power-supply/base and the sculpted, copper-accented main chassis makes for a brilliant and dramatic visual presentation. And I've never seen a more physically attractive power supply. The assembled stack is relatively tall at 7.5" and requires 3" top clearance. It's best placed atop, not in, a rack. That way, you also get the best view.
Inside the preamp proper, six central, vertically mounted circuit boardsone for each input, and stuffed with "through hole" components rather than surface-mount typesare aligned parallel to the front and rear panels. A seventh board at the rear holds the six sets of balanced XLR inputs and two sets of balanced XLR outputs. Ribbon cables connect the boards, helping to produce an utterly neat and tidy interior reminiscent of the innards of my long-term reference, the darTZeel NHM-18NS. Neither preamp includes sausage-sized capacitors.
The complementary, balanced, zero-feedback Momentum is DC-coupled, has no capacitors in the signal path, and features fully discrete circuitry with no op-amps. Volume adjustment is via an optical controller and resistor ladder.