93%
Dan D’Agostino PROGRESSION S350 STEREO AMPLIFIER
Power and Performance
The Progression S350 Stereo Amplifier leverages the innovative Super Rail circuitry employed in the M550 Monoblock, unique technology whose output stage operation results in improved dynamics, lower distortion, and a fierce grip of the loudspeaker. Every amplifier employs positive and negative voltage rails that deliver power to the speaker. The music signal swings between these two rails, but due to natural loss, the signal never reaches the output rails’ full capability. A Super Rail overcomes this limitation by boosting voltage in the sections prior to the output stage.
A Substantial Foundation
Abundant power is required for realistic sound quality and is a cornerstone of Dan D’Agostino Master Audio Systems’ amplifier design. The graceful, anodized aluminum chassis of the Progression S350 houses a 2,000 VA power supply transformer coupled to nearly 100,000 microfarads of power supply storage capacitance. Paired to this foundation is a fully complementary driver stage, and output circuitry outfitted with 48 power transistors—24 each for the left and right channels generating an imposing output. Initially used in the Relentless Series, the output power device provides the foundation for an upgraded output stage. This transistor extends high-frequency response, increases power handling 50%, 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 heatsink allows operating bias to be increased, lowering crossover distortion and improving instrumental timbre and tonal accuracy.
Elegantly Powerful
Drawn directly from the Relentless M550 Monoblock Amplifier, each heatsink is milled from a single, 48.5-pound (22 kg) aluminum billet slab whose highly efficient elliptical form dramatically improves cooling ability and assures reliable operation even when delivering full-rated power, an impressive 350 watts per channel into 8 ohms. Output doubles to 700 watts per channel into 4 ohms and 1,400 watts per channel into2 ohms.
Combining innovative circuitry and significant power, the Progression S350 Stereo Amplifier lets loudspeakers achieve their full sonic potential, with music’s dynamic contrasts and leading-edge transients spectacularly depicted and faithfully reproduced.
Dealers selling Dan D’Agostino near you
Dan D'Agostino PROGRESSION S350 STEREO AMPLIFIER
The PROGRESSION S350 marries brute force with exquisite nuance: a 350 Wpc Class-AB design that supplies prodigious current and a near-transparent, extended-top presentation. Reviewers including Tom Lyle and Ken Kessler praise its visceral dynamics, delicate treble and deep, well-focused imaging that projects a large, lifelike soundstage. Its large power supply and low output impedance translate to firm speaker control and punch without losing microdetail or tonal weight. The 115 lb anodized-aluminum chassis and signature dual-needle meter underscore a bombproof, watch-inspired finish. Ideal for listeners with revealing systems and demanding speakers, the S350 rewards careful system matching with impressively coherent scale, speed and clarity.
Pros
- Exceptional dynamics and speaker control—delivers high headroom and a fierce grip that drives demanding speakers with authority.
- Near-transparent, detailed midrange and a refined treble presentation that avoids harshness while retaining air and extension.
- Expansive, precisely layered soundstage and imaging—excellent separation and a solid center image for convincing realism.
- Robust, high-end build and presentation—substantial anodized-aluminum chassis and signature meter convey premium fit and finish.
&
Cons
- Very heavy and bulky (115 lb) with no handles, making placement and servicing awkward for most users.
- Balanced-only connectivity (XLR) limits direct compatibility with single-ended sources and some legacy preamps.
- Highly resolving nature can expose poor recordings or upstream components—performance is system-dependent.
Sound Quality
93/100
Dynamics
93/100
The S350 delivers exceptional headroom and control for its class: spec'd at 350 Wpc into 8 Ω (700 Wpc into 4 Ω, 1,400 Wpc into 2 Ω) with a low output impedance (0.1 Ω), and reviewers repeatedly describe it as a "powerhouse...seemingly without limit", with "brutal take-no-prisoners power delivery" and a "fierce grip" on speakers. These comments plus the amp's ability to deliver large current into low impedances justify a top-tier dynamics score in the Class‑AB 200–400 W band.
Soundstage Imaging
92/100
Multiple reviews highlight outstanding imaging and scale: "gigantic soundstage", "voices arriving as if from nowhere", "solidity of the center image", and previously 'unmatched' separation. The S350 preserves and expands spatial cues even at high levels, supporting a score at the high end of imaging performance.
Show Less
Build Quality
91/100
Physically substantial and well made: 115 lb anodized‑aluminum chassis described as "bombproof" and with front‑panel styling "inspired by a Swiss watch." Reviews note a robust, minimal rear panel (balanced XLR only, heavy binding posts) and implied large power supply capacity; overall construction and thermal/PS design impressions justify a very strong build score.
Value for Money
90/100
Contextual value: list/market price ~ $30,000 and 350 Wpc output. Reviewers say it competes sonically with an earlier Momentum that cost substantially more and one reviewer 'has no problem recommending' it to those who can afford it. While this is an expensive amplifier, reviewer sentiment frames it as a justified premium in its segment rather than overpriced, so it earns a high value score (justified premium).
Reviews
Online Reviews & Mentions
YouTube Reviews
Forum Mentions
No forum mentions found yet
FAST, EASY & NEAR
Find Dan D’Agostino Verified Dealers Near You
Dan D’Agostino dealers in the map