Price lowered, any interest at $400??

Pretty amazing sound quality at this price of entry. Plenty of reviews.
HYPEX UCD 180 HG HxR
What do you look for in a power amplifier? Bet it's the sound. Hypex UcD amplifier modules are designed from the ground up for true fidelity. Available in 180W, 400W and 700W variants, they represent a new generation of switching power converters truly performing as amplifiers.
Features
Flat, fully load-independentfrequency response
Low output impedance
Very low, frequency-independent THD
Very low noise
Consistent top performer in listening trials including class Aand SET amplifiers
Runs on unregulated +/- rails
Pop-free start and stop control
Differential audio input
Overcurrent, shortcurrent and over voltage
DC/AC-coupling selectable
Fits in a 2HE case when mounted on its side
4-layer PCB design
HxR regulator ready
Applications
Monitor loudspeakers for recording and mastering studios
Audiophile power amplifiers for professional and consumer use
Public Address systems
Home theatre systems
Active loudspeakers
Technology
The UcD circuit is based on phase-shift controlled self-oscillation, with only a single voltage feedback control loop taking off at the loudspeaker terminals. The control function is constructed fully out of passive components, with only the comparator standing in for gain.
Output Power PR 180W 4OHM, THD=1%
Distortion THD < 0.1% typ Po<600W
Distortion THD < 0.008% typ Po=1W
Noise Un 30uV typ
Frequency Response < 10Hz-50kHz +0,-3dB
Output Impedance Zo < 20 mOhm f=1kHz
Output Impedance Zo < 150 mOhm f=20kHz
Efficiency n > 92%
Supply Ripple Rejection PSRR 65dB Both rails
With pre-mounted HxR regulators
Description
The HPR12/HNR12 are high performance voltage regulators targeted at performance-critical audio applications. Key performance parameters exceed that of industry-standard integrated circuits by several orders of magnitude. Kelvin sense connections provide point-of-load (local) regulation with- out requiring physical proximity.
Features
Ultra-low noise
Wide bandwidth
Excellent ripple rejection
Low, load-independent output impedance
Kelvin sense connections
Size and pin compatible with TO-220 style regulators
Applications
Preamplifiers and buffers
RIAA input stages
Playback head amplifiers
Performance upgrade for existing products