Simaudio Moon P-8

These two units, Top main control & bottom power unit are in very good condition. The top, the one that sits "on top" should rest with spike feet resting into protective cushioned metal indented disks. Not using those little disks caused some scratches on the bottom unit's pillars. I have and now use those little disks! To correct this mishap, I bought a set of new bottom corner pillars from Simaudio, but never got to changing them out. [NOTE added 3/6/18: Simaudio quoted me $180 labor to change the 4 pillars, plus shipping. Also, the scratch you see in one photo is greatly highlighted by the camera flash.] The Top unit is very clean and hides the few marks on the lower power unit. The units work flawlessly. The P-8 Simaudio's Moon Evolution is a two-chassis system: it comprises the Controller chassis, which contains the display, all the controls, and a power supply capable of driving the Preamplifier chassis and an additional device, such as a phono stage or DAC. All AC is contained within the Controller chassis, which connects to the Preamplifier chassis by means of two four-pin XLR cables, each providing the DC supplies for a single channel. The Controller directs the Preamplifier functions via a cable using an 8-pin Ethercon connector within the XLR shells. All audio signals are kept within the Preamplifier chassis. Despite this separation of powers, the two units operate as one. Inside the Controller are two entirely dual-mono power supplies, fed from three toroidal transformers. Sim is obsessive about supply filtering, to the point of adding an inductive filter at each and every chip in the Preamplifier's audio path: a total of 40 such stages in all. This is in addition to using four-layer PCB construction for better grounding and shorter signal paths. The extremely silky volume control operates via a system called M-Ray, which consists of a pair of R-2R resistor ladders similar to those in DAC chips, but with 0.1% tolerances and 530 individual steps of 1dB (0–30dB) and 0.1dB (30–80dB). I generally used levels in the 40–65dB range and benefited from the smaller increment. In addition, the volume control array can be programmed for each input for gain offset (to balance their volume levels) and maximum volume (to prevent excessive output). Also, any input can be set to a fixed 0dB gain with volume control inoperable, so that it can operate as a home-theater bypass. Adjustment of the left/right balance is available only from the remote control, which continues Sim's tradition of hefty, club-like remotes. It lies snugly in the hand and manages all the basic operations of the P-8, as well as other associated equipment. Just don't drop it on your toe. The main power switch is on the Controller's rear panel, along with an IEC power connector and AC fuse post. Also on the rear panel are the XLR DC power connections, modular communications connectors, dual 12V trigger outputs, RS-232 connector, IR control input, and in/out receptacles for SimLink, a proprietary communications/control protocol for other Moon Evolution devices, such as the W-8 and the Andromeda CD player. On the Preamplifier's rear, the four RCA inputs and the three XLR inputs are symmetrically placed on the extreme left and right, respectively, with the output and tape-loop jacks clustered in the center around the DC supply and communications connectors. The front of the Preamplifier, which contains all the audio circuitry, bears nothing more than a centrally located LED to indicate that it is powered and operational. The user interface is the front of the Controller and the remote control. The large, smooth-turning volume knob and the large digital display dominate the controller's face. The display—large, bright (or not—it's adjustable), and configurable—joins those of the Camelot Uther and the Meridian Reference 861 in the pantheon of the most informative and legible displays I have used. From first power-up, the Evolution P-8 performed faultlessly and impressively. It was, by far, the quietest preamp I have ever (not) heard. Even with my ear to a tweeter and the volume full up, I could hear absolutely no difference between Standby and Operate. In other words, any noise that the P-8 might generate—and nothing is completely silent—was much lower than that from any of the power amps I played it through. Specifications Description: Solid-state, two-channel, two-chassis preamplifier. Inputs: 3 pairs balanced (XLR), 4 pairs single-ended (RCA). Outputs: 2 pairs balanced (XLR), 2 pairs unbalanced (RCA, fixed and variable). Tape input/output loops: 1 pair unbalanced (RCA). Input impedance: 11k ohms. Output impedance: 50 ohms. Voltage gain: 9dB. Frequency response: 5Hz–100kHz, +0/–0.1dB. IM distortion: unmeasurable. THD: <0.002%, 20Hz–20kHz. Signal/noise ratio: 130dB, 20Hz–20kHz, ref. full output. Maximum output: 12V balanced, 6V unbalanced. Dimensions: Preamplifier: 18.75" (480mm) W by 4" (100mm) H by 16.5" (420mm) D. Controller: 18.75" (480mm) W by 5.5" (140mm) H by 16.5" (420mm) D. Weight: 74 lbs (33kg). SERIAL # I421292 (first digit is the letter "I"). I have the original box; remote; cables; manual; spike feet & indented disks.