D’Agostino Momentum C2 Preamplifier – Quick Look

All Image Credit: Dan D’Agostino

Dan D’Agostino has released the Momentum C2 (“Concept 2”) preamplifier. The C2 succeeds the Momentum HD model released in 2019 and now includes; an advanced circuit topology and power supply, plus improved digital functionality and an optional digital streaming module.

The Momentum C2 weighs in at 73lbs (33.1Kg) and includes technical features and sonic attributes used by the flagship Relentless Preamplifier. It is composed of two chassis, the dedicated audio chassis, and the separate power supply chassis, both interconnected using thirty-pin interlocking gold-plated connectors that are rated to handle 20 amps.

The power supply uses separate toroidal transformers for the analog and digital circuitry and it addresses RF noise from the AC  power line, compensating for asymmetric power waveforms and DC on the mains. This two chassis arrangement achieves optimal mechanical and electrical isolation, resulting in a claimed 105 dB, unweighted signal-to-noise ratio.

Using no negative feedback and a DC coupled design throughout, each channel of the C2 uses four JFET transistors arranged in a unique and discrete dual-complementary differential push-pull arrangement, increasing the input impedance to 1M ohm and being capable of handling input voltages of 30volts. This high input impedance is said to significantly help isolate it from extraneous noise, reduce the overall noise floor and help create a distortion measurement of <0.002%, 20 Hz to 20 kHz (full output), with a claimed frequency response of 0.1 Hz to 1 MHz, –1 dB / 20 Hz to 20 kHz, ±0 dB.

Other internal design features include; the use of four-layer circuit boards, the isolation of analogue and digital circuit elements and ground planes, digital control signals are optically coupled to analogue circuits and signal-switching relays are hermetically sealed and use gold-plated contacts. Even the volume control uses military-grade, high-linearity solid-state switches and discrete precision resistors ensuring precise control with no impact on the bandwidth and transient response of the C2.

Control is available using the front panel buttons and rotary controls, the supplied rechargeable remote control that is housed in precision-machined aluminum and Delrin body and uses Bluetooth to connect to the system, mirroring the Momentum C2 Preamplifier’s front panel information or by using the iOS app. Two LCD displays provide the units volume level, input, status and functions. The display on the power supply showing unit status, functions and metadata (with DSM), while the display on the pre-amplifier provides volume level and input.

Rear panel signal connectivity includes; 3 x balanced XLR stereo and 1 x unbalanced RCA stereo and 2 balanced XLR stereo outputs. While the front panel contains a 1/4″ headphone jack that is concealed behind a discrete door and features its own independent amplifier circuitry.

For those wish to add digital connectivity there is an optional Digital Streaming Module (DSM). This module incorporates SPDIF coaxial, Optical, USB-B, RJ45, and Wi-Fi network inputs and decodes PCM signals up to 32-bit/384 KHz, DSD signals up to DSD256 (11.2MHz) natively and supports 10/100/1000 Gigabit Ethernet.

Apple users can download the iOS app to control music collections, streaming content, and unit functions. The app supports native integration with subscription streaming services to include; Tidal, Qobuz, and Spotify and is also compatible with Tidal Connect and MQA. For Android users or if you have a Roon account, Roon Ready certification will also be available.

Finally, the Momentum C2 Preamplifier, available in silver, black, or custom-painted finishes.