More Information about Moon by Simaudio 870A Power Amplifier-BLACK
The Moon Evolution 870A, which measures 18.75”W x 7.5”H x 17.5”D and weighs about 90 pounds, is Simaudio’s largest, most powerful, most expensive stereo amplifier. Above the 870A in the line is the Moon Evolution 880M monoblock, which is rated at 800W into 8 ohms; below it are the Moon Evolution 860A and 760A stereo models, at 200 and 130Wpc into 8 ohms, respectively.
The 870A delivers its claimed power output with 16 proprietary, ideally matched Moon bipolar output transistors per channel, and has 300,000µF of power-supply capacitance. Since the 870A is dual-mono, its power supply includes two 1.3kVA transformers. At the heart of the design is Simaudio’s Lynx circuitry, which they describe as “a ‘no overall feedback’ design resulting in genuine real-time amplification, a more accurate musical reproduction with respect to tonality, virtually non-existent IMD [intermodulation distortion] and the elimination of common phase errors resulting from feedback.” Four-layer circuit boards with copper tracings are used for the shortest signal paths, which Simaudio says “results in greater sonic accuracy and a dramatically improved signal-to-noise ratio.”
The 870A’s other specs are also impressive. For example, the total harmonic distortion (THD) at 1W output is said to be less than 0.015% from 20Hz to 20kHz, and less than 0.04% for 300W output across the same bandwidth. Intermodulation distortion, something Simaudio’s design team contends is more relevant than THD when it comes to sound quality, is claimed to be “unmeasurable.” The claimed output impedance is less than 0.01 ohm, and the corresponding damping factor exceeds 800, which is pretty high (Simaudio specifies no frequency point or range for either figure).