MOON Evolution 850P Preamplifier

MOON Evolution

The MOON 850P is the most advanced MOON preamplifier to date.


Extensive research and development, coupled with recent advancements in electronic parts have provided us with the foundation to design what may very well be the transparent, quietest, most accurate and uncolored preamplifier. Targeted to the discerning listener who desires uncompromising musical reproduction, the 850P features numerous proprietary technologies.

Our M-Octave Damping damping system that eliminates the sonically degrading effects of microphonics by mounting the main audio circuit on an 8-point floating suspension. The result is a more natural, liquid and lifelike sound. Since listening environments are typically loaded with acoustically induced vibrations that originate from the loudspeakers, we use M-Octave to isolate the 850P from these microphonic-causing vibrations, allowing you to hear more music, exactly the way it was recorded.Other in-house technologies include (i) i²DCf power supply voltage regulation, (ii) M-Ray volume control, with a phenomenal 530 steps, allowing for an extremely precise level adjustment, (iii) SimLink and (iv) M-Lock, just to name a few, as well as an RS-232 connection, IR port and 12 Volt triggers for custom-install environments.

Significant Design Features:

  • 2-chassis design with 1 chassis housing the power supply, digital controller circuitry, software processing & the LED display. The other chassis contains ONLY audio circuitry.
  • Power supply voltage regulation includes i 2 DCf (Indepen- dent Inductive DC Filtering); 1 inductor for each and every IC in the audio circuit’s signal path – 40 stages in all.
  • Gain offset adjustment of ±10dB for each line input.
  • Each line input is fully configurable to be “home theater ready”, whereby the 740P’s volume control is bypassed.


  • 2-chassis design with one chassis housing the power supply, digital controller circuitry and software processing. The other chassis contains the audio circuitry
  • The preamplifier's audio section is located on its own dedicated circuit board, which is mounted to the chassis with our M-Octave Damping system
  • A dual-mono oversized power supply using 2 toroidal transformers in conjunction with 6 stages of DC voltage regulation and extensive choke filtering
  • M-Ray volume control based on the R-2R resistor array configuration using metal film surface mount resistors with 0.1% tolerances, resulting in no sonic degradation of the audio signal, regardless of the selected volume setting
  • Power supply voltage regulation includes i²DCf (Independent Inductive DC Filtering); There is one inductor dedicated to each integrated circuit type component (DAC, Op-Amp, etc.) in the audio circuit's signal path; 40 stages in all
  • Fully differential, no global feedback circuit topology, using absolutely no capacitors anywhere in the audio signal path
  • M-Lock for "user selectable" maximum volume setting lock-out for each line input
  • "Gain offset" for each individual line input with a ±10dB range
  • Each line input is fully configurable to be "home-theater ready", where the gain section of the 850P is bypassed
  • RS-232 port for (i) full unsolicited bidirectional feedback and (ii) firmware updates
  • IR input for external control
  • 12 Volt trigger output for remote operation
  • SimLink™ controller port for 2-way communications with other compatible MOON components
  • 4-Layer printed circuit boards with pure copper tracings for a much shorter signal path; This results in greater sonic accuracy and a dramatically improved signal-to-noise ratio
  • Ultra rigid chassis construction to minimize the effects of external vibrations
  • Accurate matching of the very finest quality electronic components in a symmetrical circuit design
  • Includes FRM-3 remote control
  • Circuit Topology Open loop
  • Input Sensitivity 200mV - 4.0V RMS
  • Input impedance 11,000Ω
  • Gain 9dB
  • Max. output voltage (XLR / RCA) 15V/7.5V
  • Signal-to-noise Ratio (20Hz-20kHz) 130dB @ full output
  • Frequency response (full range) 5Hz - 100kHz ±0.1dB
  • Crosstalk @ 1kHz -130dB
  • Output impedance 50Ω
  • THD (20Hz-20kHz) < 0.0005%
  • Intermodulation distortion Unmeasureable
  • Shipping weight 151 lbs / 67 Kgs
  • Dimensions - Preamplifier (W x H x D) 18.75 x 4.0 x 16.5 in.
  • Dimensions - Controller (W x H x D) 18.75 x 5.5 x 16.5 in.

Download User Manual