Dan D'Agostino Mono Amplifiers

Progression M550 Mono Amplifier
High Performance Elevated

Immediately grabbing one’s attention is the new heat sink design. Drawn directly from the flagship Relentless Mono Amplifier, each heatsink is milled from a single, 48.5-pound (22-kilogram) aluminium billet slab. This highly efficient elliptical form dramatically improves the cooling ability of the design and assures that the Progression M550 Mono Amplifier runs safely and reliably even when delivering its full-rated power. Reflected in the model name, the Progression M550 Mono Amplifier delivers 550/1,100/2,220 watts into 8/4/2 ohms.

The Progression M550 includes major revisions to the input topology. Distortion, signal/noise ratio, channel separation, and bandwidth measurements have all improved. New transistors handle six times the power of the previous components and a new DC coupling circuity has improved low frequency performance and extended the bandwidth of the amplifiers. Pairing this advanced front end to the enhanced output stage has improved the dynamic impact, detail retrieval, and spatial integrity of the amplifier’s playback. The audio signal path throughout is discrete, balanced, and direct coupled. Advanced protection techniques shield the amplifier and associated components from any unexpected anomaly.

Exploring New Dimensions

A new power device provides the foundation for an upgraded output stage. This new transistor, first used in the Relentless Mono Amplifier, extends high frequency response, increases power handling by a factor of four and features tighter tolerance gain matching between complementary NPN/PNP pairs. A wider safe operating area and superior gain linearity provides greater thermal stability throughout the amplifiers’ power delivery. Coupling the new output device to the high efficiency heat sink design affords an increase in operating bias. The higher bias specification has increased the Class A operating range of the Progression M550 to 70 watts. The result is improved instrument timbre and tonal reproduction for a great percentage of listening.

Maintained from the original amplifier is the Super Rail topology, a simple concept but complex in execution. Every amplifier employs a voltage rail, actually two, a positive one and its companion negative partner. Voltage rails support the delivery of power to the speaker. The music signal swings between these two rails but due to natural loss, the musical signal never reaches the output rails’ full capability. A Super Rail overcomes this limitation. Borrowing the idea of a turbo in a car engine, the Super Rail employs higher voltage rails in the sections prior to the output stage. This voltage "boost" allows the musical signal to exploit the full capability of the output voltage rails. Extending the musical signal swing closer to the output rails maximizes the performance of the output circuitry design itself. Nearly ideal output stage operation results with improved dynamics, lower distortion, and a fierce grip of the speaker. The output topology employs 48 power transistors anchored by a 2,000 VA power supply transformer and nearly 100,000 microfarads of power supply storage capacitance.

Legendary Purity

The anodized Aluminium faceplate includes the iconic look of the company’s power meters. The Progression M550 Mono Amplifier 180° meter needle is driven by a high-speed ballistic circuit improving the meter’s responsiveness. The Progression M550 Mono Amplifier features a 180° needle arc meter design driven by a high-speed ballistic circuit that enhances the meter’s responsiveness. The longer needle arc covers the amplifier’s entire output range. With innovative circuitry and virtually unlimited power output, the Progression M550 Mono Amplifiers deliver intimate musical details, three-dimensional sound staging, and startling dynamics not possible from less capable designs.

Momentum M400 MxV Mono Amplifier
Advancements in Every Area

Every major section of the amplifier - power supply, input, driver, and output stages - have all been enhanced in this advancement. A new transformer winding pattern provides over 50% more current output from the same transformer footprint. This additional current offers greater headroom during dynamic passages. A re-envisioned input stage combines a brand new circuit topology with advanced components feeding the driver and output stages. Crucial to the new circuit are the bipolar transistors powering the front end of the amplifier. In the Momentum M400 MxV amplifiers, new devices deliver ten times the current and power of the original devices. These wider bandwidth, higher power components extend low and high frequency performance with reduced distortion in both frequency extremes. 

Energizing the driver stage is a new bias stability circuit providing a nearly 50% increase in operating bias. Increasing Class A operation directly correlates to better sound quality. However, there is a limit to bias level in any amplifier. With this new circuit topology and our unique Copper heatsinks, thermal issues are not a practical concern in the Momentum M400 MxV amplifiers. The new bias scheme ensures bias consistency, preventing excessive temperatures even under the greatest demand. Additional power transistors in the output stage reduce workload for each device. By minimizing stress on each individual device, the entire output section works more efficiently. The result is a richer, more dynamic, intimate presentation regardless of musical genre.

The final output stage features new output transistors that were originally sourced for the flagship Relentless Monoblock Amplifier. The high-output transistors used on the Momentum M400 MxV are among the fastest available. Using 26 on the Momentum M400 MxV amplifiers they run at a blistering 69 MHz, permitting the Momentum M400 MxV to achieve incredible bandwidth. Each transistor mounts with two stainless steel fasteners—a rarity among flat-package transistors—for maximum thermal transfer to the copper heat sinks. A capacitor/resistor network connected to the base of each transistor ensures stability even at high frequencies and with low-impedance speakers. Additionally, every output transistor is measured and only devices that match the required performance specifications are included in the production of Momentum M400 MxV amplifiers. As with all D'Agostino models, the Momentum M400 MxV amplifiers feature discrete, direct-coupled balanced circuitry, the most accurate circuit platform possible.

Power to Spare

Defying its compact size, the Momentum M400 MxV is a powerhouse amplifier. The backbone is the new ultra-quiet 1,800VA linear transformer with almost 50% greater current output. This engine drives a nearly 100,000μF capacitor bank resulting in 400/800/1,600W of power output into 8/4/2Ω speaker loads for the Momentum M400 MxV The Momentum M400 MxV amplifiers are capable of driving any loudspeaker to its fullest potential.

Innovative Cooling with Venturi Style Heatsinks

A critical element of any amplifier output stage is circuitry known as the driver section. In the new Momentum M400 MxV, this stage is a fully complementary design. Individual transistors are employed for the positive and negative halves of the musical signal. This 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.

Hand-built and individually tested.

Each Momentum M400 MxV monoblock amplifier is hand-built and individually tested in D'Agostino's Arizona factory by our team of technicians and craftsmen.

Upgrading to the MxV performance

The new Momentum M400 MxV employs the same chassis as previous Momentum amplifiers. All generations of Momentum Mono amplifiers can be upgraded to the Momentum M400 MxV performance level. All electrical enhancements are included in the upgrade while the original metalwork is retained. Original Momentum amplifiers receive a new 400 Watt meter plate reflecting the power output increase included in the upgrade. Momentum M400 units already have this power increase and meter.

Progression M550 Mono Amplifier

Momentum M400 MxV Mono Amplifier