The MOON story

Canadian engineering since 1980, devoted to revealing the recording: not spectacle, not excess.

Founded 1980 in Québec, Canada (today Boucherville, near Montréal) by Victor Sima · simaudio.com

MOON by Simaudio has designed and hand-assembled its electronics in Québec since 1980. This page gathers the company's story, the technologies that carry its name, and the MOON components Pearl Audio represents in Portland. Browse all MOON at Pearl Audio or arrange an audition.

Simaudio began in 1980, when Victor Sima, an engineer and musician, founded Sima Electronics in Québec to build amplifiers for people who found mass-market audio wanting; its early PW2000 amplifier was aimed first at professional users. The company's own timeline places the Celeste series and the Simaudio Ltd. name at 1990, and the Celeste i-5080 integrated amplifier, which brought the firm's preamplifier and power amplifier work into one chassis, gave it a following. In 1997 Simaudio introduced the MOON Series, a reference-grade line that moved the company into the high end. The MOON i-5 integrated amplifier, the W-5 power amplifier and the P-5 preamplifier defined the period and set the house values that still hold: amplifiers without global feedback, dual-mono construction, and a sound that reveals rather than flatters.

Under Jean Poulin, owner and chief executive for nearly two decades, the company grew from a 3,000-square-foot shop to a 46,000-square-foot, vertically integrated factory in Boucherville, across the St. Lawrence from Montréal, and MOON became a brand sold around the world. The 2000s added home theater, the MOON ROCK monoblock and the Attraction processor, and then the Evolution Series brought the brand into a new tier: the 750D, the fully balanced converter Simaudio counts as its digital milestone, and the Evolution 850P preamplifier, shown at CES in January 2011 with its two-chassis layout, eight-point floating suspension and M-Ray 530-step volume control, which became the reference for everything that followed. In 2012 Simaudio launched its first network streamer, the 180 MiND, and with it MiND, the MOON intelligent Network Device.

In September 2013 Poulin handed the company to three of its own people: Costa Koulisakis, who had spent thirteen years building its sales and customer relationships; Thierry Dufour, chief engineer for almost twenty years and the designer behind its award-winning products; and Louis Lemire, an engineer with a business background. Their commitment was that MOON would continue to be engineered and manufactured in-house in Québec. The 888 monoblock, shown as a prototype at CES 2017 and shipped in 2018, was their statement piece: 888 watts into 8 ohms, 32 hand-matched bipolar transistors mounted in cast heat sinks machined to a thousandth of an inch, no global feedback, and about a week on the bench for each one. MiND 2, the second-generation streaming platform, arrived the same year.

The modern MOON took shape over the following years. In 2022 the ACE all-in-one player won the EISA High-End Stereo System award, confirming that the company's streaming platform could carry a complete system. In May 2023 at HIGH END Munich the company unveiled the North Collection, six components (641, 681, 761, 791, 861, 891) that introduced MDCA distortion-cancelling amplification, the MDE digital engines, the M-RAY2 and M-VOL3 volume controls, MOONLink system control and the BRM-1 Bluetooth remote; Stereophile measured the 861 and called the result "one of the best I have encountered." In 2025 the Compass Collection followed, opening with the 371 Network Player / Amplifier, EISA's Premium Integrated Amplifier 2026-2027, and continuing with the 491, 461 and 341, bringing MDCA and the MHP hybrid power supply to a more accessible range. MOON International now carries the brand beyond North America.

The philosophy has not changed since the i-5. Simaudio describes its aim as bringing listeners "closer to the emotional truth of a performance," revealing the recording "with natural authority and emotional depth," and sums up the design brief as "Not spectacle. Not excess." Every MOON component is still designed, hand-assembled and tested in Boucherville, backed by a ten-year warranty with registration, and the company counts more than 400 awards worldwide. Pearl Audio has represented MOON since April 2026.

Milestones

1980 Sima Electronics founded Engineer and musician Victor Sima founds the company in Québec; its early PW2000 amplifier is aimed first at professional users.
1990 Simaudio Ltd. and Celeste The company's timeline places the Simaudio Ltd. name and the Celeste series here; the Celeste i-5080 integrated amplifier earns a following.
1997 The MOON Series Simaudio launches MOON as its reference-grade line. The i-5 integrated amplifier, W-5 power amplifier and P-5 preamplifier define the period.
2010 30th anniversary Limited editions of the MOON 600i and the Evolution 750D converter in high-gloss red, each with a 30-year warranty.
2011 Evolution 850P The two-chassis flagship preamplifier is shown at CES: eight-point floating suspension, dual-mono supply and the M-Ray 530-step volume control.MOON 850P Preamplifier
2012 MiND The 180 MiND is Simaudio's first network streamer, built on MiND, the MOON intelligent Network Device. The 810LP reference phono preamplifier arrives the same year.MOON 810LP Phono Preamplifier
2013 New owners from within Jean Poulin, owner and CEO for nearly two decades, passes the company to Costa Koulisakis, Thierry Dufour and Louis Lemire. Production stays in-house in Québec.
2018 888 and MiND 2 The 888 monoblock ships (888 W into 8 ohms, 32 matched bipolar transistors, no global feedback) after its CES 2017 debut; MiND 2 is shown at HIGH END Munich.MOON 888 Power Amplifier
2022 EISA award for the ACE The MOON ACE all-in-one player wins the EISA High-End Stereo System 2022-2023 award.
2023 North Collection Unveiled at HIGH END Munich: 641, 681, 761, 791, 861 and 891, introducing MDCA, the MDE digital engines, M-RAY2 and M-VOL3 volume control, MOONLink and the BRM-1 remote.MOON 891 Network Player / Preamplifier
2025 Compass Collection The 371 Network Player / Amplifier opens a more accessible range built on MDCA and the MHP hybrid power supply, and wins EISA's Premium Integrated Amplifier 2026-2027; the 491, 461 and 341 follow in 2026.MOON 371 Network Player / Amplifier
2026 MOON at Pearl Audio Pearl Audio becomes a MOON dealer in April 2026 and brings the North Collection to Portland.

MOON at Pearl Audio

Pearl Audio became an authorized MOON dealer in April 2026 and keeps the North Collection on the floor in Portland. Our MOON representative is Ari Margolis. Ask us about registering your MOON purchase for the 10-year warranty (registration must be completed within 30 days); we handle delivery and setup ourselves.

On demonstration in Portland now

All MOON at Pearl Audio

Signature technologies

The engineering behind MOON

MOON gives its technologies names because each one solves a specific problem. Here is what each does, where it came from, why it matters in a system, and what you may hear.

Signature technologySince 2023

MDCA (MOON Distortion-Cancelling Amplifier)

A correction circuit that runs in parallel with the signal path, measuring the output stage's error and cancelling it, so the amplifier can do without a global feedback loop yet measure like one that has it. Read the deep diveClose

What it does

Most amplifiers reduce distortion with global negative feedback: a sample of the output is returned to the input and the loop corrects the difference. MDCA leaves the signal path open-loop. The input signal is duplicated and sent to a proprietary parallel circuit built around a precision comparator, which determines how far the output stage is departing from the input and feeds that correction into the audio path. Simaudio's chief executive, Thierry Dufour, conceived the approach and handed it to the engineering team to perfect. The result is a Class A/B amplifier that behaves like a no-feedback design, with no loop wrapped around the output devices and no dependence on the loudspeaker to close it, yet with the measured distortion of a heavily corrected one. Simaudio puts the improvement at almost a factor of ten at high power compared with its previous output stages.

Why it matters in a system

A global loop corrects after the fact, and how well it works changes with the load: a reactive loudspeaker or a sudden transient can leave the correction a fraction late, which is often heard as a hardening of the sound at volume. Because MDCA's correction never passes through the loudspeaker, a MOON amplifier keeps the same character into a benign two-way or a demanding 4-ohm floorstander, and it stays composed when a passage peaks. In practice it widens the choice of loudspeaker and lets a 100- or 125-watt integrated amplifier drive loads that would normally call for separates.

What you may hear

Low-level detail that stays intact at high volume, bass that starts and stops without overhang, and no texture of the amplifier's own added to the recording. Measured, the 861 produced 0.0008% THD+N at 50 watts into 8 ohms and 360 watts at clipping on Stereophile's bench, and the 371 held its distortion below 0.0003% at 50 watts; John Atkinson called the 861's figures "superb measured performance for a power amplifier, one of the best I have encountered."

Lineage

Named with the North Collection, unveiled at HIGH END Munich in May 2023 (641, 761, 861); SoundStage! Hi-Fi records that MDCA "was first introduced in the North Collection." Simaudio's current description of the 888 monoblock (prototype at CES 2017, shipped 2018) also uses the term, so the company treats its flagship as the ancestor of the approach. Carried into the Compass Collection: the 371 (September 2025), then the 461 (2026) and the 341 (October 2026).

Proof

Manufacturer specifications: 861 THD+N 0.001% at 300 W into 8 ohms, signal-to-noise 119 dB; 761 THD+N 0.001% at 200 W; 641 THD+N 0.003% at 125 W; 371 and 341 THD+N 0.003% at 100 W. Stereophile (Jason Victor Serinus, December 2024, MOON 861): the correction is performed "in a special proprietary parallel circuit path" using "a precision comparator circuit that determines the amount of distortion," and Simaudio claims it will "reduce distortion by almost a factor of 10 at high power" (manufacturer claim). John Atkinson's measurements of the 861: 0.0008% THD+N at 50 W into 8 ohms, 360 W into 8 ohms and 650 W into 4 ohms at clipping, "superb measured performance for a power amplifier, one of the best I have encountered." Stereophile measurements of the 371 (May 2026): distortion below 0.0003% at 50 W, 135 W into 8 ohms and 265 W into 4 ohms at clipping. SoundStage! Hi-Fi (Doug Schneider, 1 October 2025): MDCA "was first introduced in the North Collection." What Hi-Fi? (Kashfia Kabir, 3 May 2023) reports Simaudio's claim of distortion reduced to "previously unattainable levels" (manufacturer claim).

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Signature technologySince 2025

MHP (MOON Hybrid Power)

A power supply that pairs a switch-mode front end with linear regulation: the efficiency and energy reserve of switching, the quiet DC of a linear supply, and a switching frequency kept far above the audio band. Read the deep diveClose

What it does

A conventional linear supply, transformer, rectifier and capacitor bank, is quiet but heavy, and its reserve is fixed by the iron and the capacitance. A switch-mode supply is compact and efficient but can leak its switching products into the audio circuits. MHP uses the two in sequence. A switching stage with active power-factor correction converts the mains to high-voltage DC; an LLC resonant stage transfers that energy with low electromagnetic emission; linear regulation then delivers the final low-impedance rails to the audio circuitry. The switching frequencies sit beyond the audio band, and the regulated stage sits between the switcher and the signal. In the 341 and 371 the supply is rated at 800 watts of continuous DC, which is how a chassis 16.9 inches wide that ships at 20 pounds delivers 100 watts per channel into 8 ohms and 200 into 4. The 461 carries two MHP modules, one per channel.

Why it matters in a system

An amplifier can only be as clean and as dynamic as its power supply. A supply that sags under a bass transient compresses the music; one that modulates the rails with switching noise blurs fine detail. MHP addresses both: the energy reserve is large relative to the output, and the rails the audio circuits see are linear and quiet. For the listener it means a compact component with the headroom of a far larger one, and it is what lets the Compass Collection be slim without being soft.

What you may hear

Dynamics that do not flatten as the volume rises, a quiet background between notes, and bass with more weight than the chassis would suggest. On Stereophile's bench the 371 delivered 135 watts into 8 ohms and 265 watts into 4 ohms before clipping, from a component that weighs 20 pounds in its box.

Lineage

Simaudio has used hybrid supplies in its line-level components for some years; SoundStage! Hi-Fi notes that MHP "has been used extensively in Moon line-level products," in the North Collection and other series. The 371 (September 2025) was the first MOON power amplifier built on it, and the name arrived with the Compass Collection. Now in every Compass component: 371 and 341 (800 W MHP with active power-factor correction), 461 (two MHP modules, one per channel) and 491.

Proof

Manufacturer specification (341 feature list): "800 W MHP – MOON Hybrid Power with Active Power Factor Correction"; 341 and 371 deliver 100 W per channel into 8 ohms and 200 W into 4 ohms at 20 lb shipping weight. Stereophile (Sasha Matson, May 2026, MOON 371): "a hybrid power supply design that brings together the strengths of both switch-mode and linear technologies," providing "a whopping 800W of continuous DC power"; John Atkinson measured 135 W into 8 ohms and 265 W into 4 ohms at 1% THD+N. hi-fi+ (Alan Sircom, 22 September 2026): the switch-mode stage feeds an LLC resonant tank to reduce interference and switching noise, followed by a linear regulation stage. SoundStage! Hi-Fi (Doug Schneider, 1 October 2025): the 371 is the first Moon amplifier to use MHP, a design previously used in Moon line-level products. Simaudio (491 page): MHP switches "above the audio band" (manufacturer claim).

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Signature technologySince 2023

MDE (MOON Digital Engine): MDE1, MDE2, MDE3

MOON's digital-to-analog architecture: a field-programmable gate array takes charge of the incoming data and its clocking, then feeds multichannel ESS converters whose outputs are summed per channel. Three grades across the North Collection. Read the deep diveClose

What it does

Rather than let a converter chip define the sound of its network players, Simaudio built its own digital engine around an FPGA. It receives PCM, MQA and DSD from the USB and digital inputs and from the MiND 2 module, reclocks the data with timing error Simaudio describes as reduced to the femtosecond range, converts 24-bit PCM to 32-bit, and feeds the result to eight-channel ESS Sabre converters. In the 891's MDE3 each channel has its own ESS 9038Pro, and its eight outputs are summed in a fully balanced analog stage so that the noise of any one converter averages down. MDE1 in the 681 is built around the ESS 9028Pro, summing two sets of four converter channels per side; MDE2 in the 791 sits between the two. All three accept PCM to 32-bit/384 kHz and DSD to DSD256, and in the 891 the digital, phono and analog boards sit on the MDB damping base.

Why it matters in a system

A streaming front end is judged on how little it adds. Timing error and converter noise are the two things a DAC can add, and MDE attacks both: the FPGA owns the clock, and the summed converter outputs raise the signal relative to the noise of any single channel. Because the engine is Simaudio's own, its firmware evolves over the life of the product, and a 681 owner and an 891 owner share one design at different levels of execution.

What you may hear

A quiet, dark background, stable stereo images that do not shift with volume, and none of the glare that makes digital tiring over an evening. The 681's 125 dB dynamic range and 0.0003% THD+N, and the 891's 0.00006% intermodulation distortion, are the measurable side of that; SoundStage! Ultra called the 891 "the quietest preamplifier I have ever evaluated."

Lineage

Introduced with the North Collection at HIGH END Munich in May 2023: MDE1 (681 Network Player / DAC), MDE2 (791 Network Player / Preamplifier) and MDE3 (891). The Compass 491 uses a different design, a dual-mono pair of ESS 9039Q2M converters, and the 371's converter is also ESS-based; neither carries the MDE name.

Proof

Manufacturer specifications: 681 THD+N 0.0003%, dynamic range 125 dB, signal-to-noise 125 dB; 791 THD+N 0.0004%, dynamic range 125 dB; 891 THD+N 0.0003%, intermodulation 0.00006%, dynamic range 125 dB. hi-fi+ (Alan Sircom, 12 September 2024, MOON 641 and 681): MDE1 is built around an FPGA and an ESS 9028Pro chipset, with picosecond-level reclocking and two sets of four DAC channel outputs summed in the analog stage. Stereophile (Jason Victor Serinus, January 2025, MOON 891): the MDE-3 "consists of an FPGA (field programmable gate array), which handles digital input data and clocking"; "each channel uses an eight-channel, 32-bit DAC"; "the DACs themselves are the ESS 9038Pro." SoundStage! Ultra (Aron Garrecht, 1 October 2024, Reviewers' Choice): "the Moon 891 is the quietest preamplifier I have ever evaluated." What Hi-Fi? (Kashfia Kabir, 3 May 2023): MDE1 is "an accuracy-led implementation of FPGA DAC architecture."

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Signature technologySince 2011

M-RAY2, M-VOL3 and MHV volume control

Volume controls built from arrays of precision resistors and discrete gain stages rather than a potentiometer, so channel balance, noise and resolution stay the same at every setting, including very quiet ones. Read the deep diveClose

What it does

A potentiometer wears, drifts between channels and changes the circuit's impedance as it turns. MOON replaced it with switched resistor networks on the Evolution 850P in 2011: M-Ray, 530 steps from 0 to 80 dB, in 0.1 dB increments over the first 30 dB and 1 dB thereafter. The North Collection carries the idea forward in three forms. M-RAY2, in the 891, is an R-2R network of 0.1% thin-film resistors offering up to 620 discrete steps selectable to 0.1 dB, working solely in the analog domain. M-VOL3, in the 641 and 791, is the third generation of MOON's electronic gain control: the knob drives an optical encoder, and an analog attenuation circuit sets the level with a claimed error below 0.1 dB between channels and between steps. MHV, MOON Hybrid Volume, in the 681, pairs fine 32-bit digital attenuation with switchable analog gain stages of 0, 5 or 10 dB, so the 681 can drive a power amplifier such as the 761 directly, without a preamplifier.

Why it matters in a system

Resolution at low volume is where many systems quietly fail. Late-evening listening, a sensitive loudspeaker, a powerful amplifier: all push the control into the range where a potentiometer's channel imbalance and noise are most audible. A resistor network has the same resolution and the same channel match at every setting, and because each step is a known value the gain can be offset per input, matched precisely to the rest of a MOON system, and read back on the BRM-1 remote's display.

What you may hear

A stereo image that stays centered as you turn the music down, steps fine enough to find exactly the right level, and no loss of texture when you listen quietly.

Lineage

M-Ray debuted on the Evolution 850P, shown at CES in January 2011 (530 steps, relays switching precision film resistors). The North Collection (2023) introduced M-RAY2 (891), M-VOL3 (641 and 791) and MHV, MOON Hybrid Volume (681).

Proof

Stereophile (Brian Damkroger, 2013, Evolution 850P): the M-Ray circuit "ranges from 0dB (no output) to 80dB (full output) in 530 steps"; "From 0 to 30dB, the increment is 0.1dB." Stereophile (Jason Victor Serinus, January 2025, MOON 891): M-RAY2 "employs 620 fully discrete separate volume settings in steps as fine as 0.1dB" and "operates solely in the analog domain"; Simaudio calls it "the finest volume control system we have ever designed" (manufacturer claim). SoundStage! Ultra (Aron Garrecht, October 2024): an R-2R network of 0.1% thin-film resistors, 140 steps in default mode and up to 620. hi-fi+ (Alan Sircom, July 2023 and September 2024): M-VOL3's optical encoder and analog attenuation with a claimed error below 0.1 dB; MHV combines 32-bit digital attenuation with analog gain stages. Simaudio 681 user manual: variable-output gain of 0 dB (2.0 V), 5 dB (3.5 V) or 10 dB (6.5 V) at 0 dBFS.

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Streaming platformSince 2018

MiND 2 (MOON intelligent Network Device)

MOON's own streaming platform, developed in-house since 2012 and now in its second generation, built into every MOON network player and controlled from the MiND Controller app. Read the deep diveClose

What it does

MiND is the network player inside a MOON component: the hardware module and the software that find music on your network and on streaming services and deliver it to the digital engine. The second generation, MiND 2, added Roon Ready certification, TIDAL and Qobuz integration and multiroom playback across MOON components, and firmware updates since have added Qobuz Connect, TIDAL Connect, Spotify Connect, Apple AirPlay, Bluetooth, UPnP/DLNA library playback and internet radio. It handles PCM to 384 kHz and DSD to DSD256, with a large playback buffer so content is cached during play. The MiND Controller app for iOS and Android browses libraries and services, controls playback and groups rooms, and the same app runs a 371, a 681 or an 891.

Why it matters in a system

Because Simaudio writes the platform itself, it decides the roadmap: new services and protocols arrive as firmware rather than as a new box, and the player is tuned to the company's own digital engines. For an owner this is the difference between a streamer that is current when bought and one that stays current. It also keeps the whole system in one hand: MiND 2, MOONLink and the BRM-1 remote were designed together.

What you may hear

Mostly, nothing you would attribute to the streamer, which is the aim: gapless playback, high-resolution files delivered intact, and quick, stable control from the phone in your hand. In Stereophile's follow-up on the 891, Tom Fine found that "Music played with the MiND app sounded better than music played through Roon."

Lineage

MiND (MOON intelligent Network Device) launched in 2012 with the MOON 180 MiND network streamer, Simaudio's first. MiND 2, the second generation, was shown at HIGH END Munich in May 2018 alongside the 390 and has since been built into every MOON streaming component: today the 371, 491, 681, 791 and 891.

Proof

The Audio Beat (Dennis Davis, 24 May 2018, HIGH END Munich): "MiND 2 is the second generation of" the Moon intelligent Network Device, with Roon, TIDAL Masters and Qobuz Sublime+ support; "You cannot buy Moon MiND 2 as a standalone product, but only as a MiND meld with Moon products." Simaudio 371 user guide (2025): Roon Ready, Qobuz Connect, TIDAL Connect, Spotify Connect, AirPlay, Bluetooth, UPnP/DLNA and internet radio; PCM 44.1 to 384 kHz, DSD64 to DSD256. Stereophile (Tom Fine, March 2025, MOON 891 follow-up): "Music played with the MiND app sounded better than music played through Roon." Simaudio FAQ: MiND 2 "supports network playback and gives listeners access to major music services through the MOON MiND Controller app" (manufacturer description). The MiND 2-based ACE player won the EISA High-End Stereo System 2022-2023 award.

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System integrationSince 2023

MOONLink

A control link between MOON components, carried over their network ports, so a system powers up, changes input and reports status as one instrument. Read the deep diveClose

What it does

MOONLink is the successor to SimLink, the mini-jack control bus that connected MOON components for two decades. It runs over the dual RJ-45 network ports on the back of every North and Compass component (and, on the Compass models, over Wi-Fi), and lets the preamplifier or network player act as the brain of the system: switch it on and the power amplifier wakes with it; the preamplifier's menu can see and adjust elements of the amplifier; standby and input selection travel across the link. A 12-volt trigger output is also provided for amplifiers that use one, and a MOONLink cable is supplied in the box.

Why it matters in a system

A separates system is only as pleasant to live with as its control. MOONLink removes the row of remotes and the sequence of power buttons, and it lets the BRM-1 remote, with its Bluetooth link and volume display, run everything from one hand. For a client building a 791 and 761 pair, or a 491 and 461 pair, it is the detail that makes separates feel like a single component.

What you may hear

Nothing, by design; MOONLink carries control, not audio. What you notice is a system that behaves as one.

Lineage

Introduced with the North Collection in 2023, replacing SimLink (the 1/8-inch mini-jack control cable still supplied with the 250i v2, the 260D and the 850P). Standard across North (641, 681, 761, 791, 861, 891) and Compass (341, 371, 461, 491), each with MOONLink on dual network ports.

Proof

Simaudio (641 page): "MOONLink connectivity for easy coordination with other North Collection components"; (761 page): "a MOONLink port for seamless startup coordination with MOON preamplifiers"; 761 user manual: the NETWORK RJ-45 ports serve "MOONLink and network extension," with 12 V trigger in and out; 371 user guide: MOONLink runs over the NETWORK connection and "MOONLink with Wi-Fi is also supported." What Hi-Fi? (Kashfia Kabir, 3 May 2023): a dedicated MoonLink feature that gives a level of integration between the products that few rivals offer (manufacturer claims as reported).

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Every MOON component we carry (10)

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Design principleSince 1986

No global feedback and MOON bipolar transistors

MOON amplifiers avoid a global feedback loop and use proprietary bipolar output transistors matched by hand, a combination Simaudio has refined since 1986. Read the deep diveClose

What it does

Simaudio's amplifier philosophy predates the MOON name. Instead of correcting the whole amplifier with one loop from output to input, each stage is made linear on its own, with only local feedback where needed, and since 2023 the MDCA correction circuit does the rest. The output devices are bipolar transistors made to Simaudio's specification by onsemi, hand-selected and matched: 24 per channel in the 860A v2, 32 in each 888 monoblock, mounted directly in cast heat sinks machined flat to a thousandth of an inch so they all run at the same temperature. The current North and Compass power amplifiers list "No Global Feedback Design" and "MOON Transistors" among their defining features, and the 250i v2 and 341 specify precision-matched MOON bipolar output transistors.

Why it matters in a system

A global loop slows an amplifier's response to a transient and can mask low-level detail; it also makes the amplifier's behavior depend on the loudspeaker it is driving. Without it, a MOON amplifier delivers current on demand and sounds the same into easy and difficult loads. The matched bipolar devices give the tight, deep bass owners describe, and they run cool enough to last decades; the North Collection's 761 and 861 can be bridged into monoblocks of 600 and 800 watts without strain.

What you may hear

Speed and openness without edge, bass that is controlled rather than merely loud, and a presentation that stays the same at low and high volume. Costa Koulisakis put the design brief to Stereophile in five words: "We do not mask anything."

Lineage

Simaudio has refined its zero-global-feedback approach since 1986 (Stereophile, MOON 888 review). It defines the 888 (2018), the 860A v2 (24 matched 250 W bipolar devices per channel), the North Collection 641, 761 and 861 (2023) and the Compass 341, 371 and 461 (2025 and 2026).

Proof

Stereophile (Michael Fremer, 2018, MOON 888): Simaudio has been "continuously refining their use of zero global feedback since 1986"; "all 32 bipolar transistors in this fully balanced, dual-differential amp consistently run at the same temperature"; "it takes about a week to assemble one 888." Stereophile (Jason Victor Serinus, 28 October 2022, 860A v2): "24 hand-matched 250W output transistors in parallel," "custom manufactured for us by Onsemi"; Costa Koulisakis: "With no global feedback, we amplify high frequencies snappily and quickly" and "We do not mask anything." Simaudio feature lists: "No Global Feedback Design" and "MOON Transistors" (761, 861, 461); "MOON bipolar transistors" (341); "Precision-matched, proprietary MOON bipolar output transistors" (250i v2).

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Design principle

Dual-mono configuration

Left and right channels built as two independent amplifiers in one chassis, each with its own power supply, so neither channel can disturb the other, and so two channels can become one monoblock. Read the deep diveClose

What it does

In a dual-mono MOON component the two channels share only the chassis and the mains inlet. Each has its own transformer or supply module, its own regulation and its own circuit board, laid out as a mirror image of the other. In the 461 that means two MHP supply modules; in the 761 and 861, two 700 VA or two 1,500 VA toroidal transformers and a rear-panel switch that bridges the channels into a single monaural amplifier (the left input is used and no adaptor is needed); in the 891 and 791 every stage is independently powered; in the 491 even the two converters run as a dual-mono pair; and the 610LP phono preamplifier is built as a dual-mono, fully balanced differential circuit.

Why it matters in a system

When one channel draws a surge of current for a bass note, a shared supply dips for both channels and the stereo image smears. Separate supplies keep the channels independent, which is why dual-mono designs measure so well for crosstalk: -114 dB on the 461, -116 dB on the 761, -119 dB on the 861, -125 dB on the 681, 791 and 891, -130 dB on the 850P. It is also what makes the mono mode on the 461, 761 and 861 credible: two complete amplifiers working together rather than a stereo amplifier straining. On Stereophile's bench the 861 delivered 1,150 watts into 8 ohms in mono.

What you may hear

Instruments that stay in place when the music gets loud, a wider and deeper stereo stage, and bass in one channel that does not cloud detail in the other.

Lineage

A MOON hallmark across generations: the Evolution 850P (CES 2011) is a true dual-mono, fully balanced preamplifier with a separate dual-mono supply chassis. Today it defines the North 641, 681, 761, 791, 861 and 891, the Compass 461 and 491, and the 610LP phono preamplifier.

Proof

Manufacturer specifications (crosstalk): -109 dB (641), -114 dB (461), -116 dB (761), -119 dB (861), -125 dB (681, 791, 891), -130 dB at 1 kHz (850P), -106 dB at 1 kHz (610LP, 810LP). Simaudio (461 page): two MHP modules, one per channel, which "supports channel separation, lowers crosstalk, and improves current delivery"; (891 page): "Each stage is independently powered in an optimized dual-mono layout"; (761 page): "two custom low-noise 700 VA toroidal transformers"; (861 page): "two 1500 VA custom low-noise toroidal transformers" and "228,000 µF of power-supply capacitance" (manufacturer claims). Stereophile measurements (John Atkinson, December 2024, 861): 1,150 W into 8 ohms in mono mode at clipping. 761 user manual: mono mode uses the MODE switch and the left-channel input, with no adaptor. The Audio Beat (CES 2011): the 850P's "separate dual-mono power supply features four stages of DC voltage regulation and extensive choke filtering."

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Every MOON component we carry (9)

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Signature technologySince 2011

i²DCf (Independent Inductive DC Filtering)

A dedicated inductor filtering the DC supply of every integrated circuit in the signal path, so each gain stage draws from its own quiet reservoir of power. Read the deep diveClose

What it does

A phono preamplifier amplifies a signal measured in fractions of a millivolt, so any noise riding on its power rails ends up in the music. MOON's answer is to give each IC in the audio path its own inductor-based filter stage: 40 stages in the 850P preamplifier, 24 in the 810LP and 610LP phono stages, 2 in the compact 310LP, with the same inductive DC filtering principle in the 110LP v2. Behind the filters sits multi-stage voltage regulation, four stages of what Simaudio calls M-LoVo (MOON Low Voltage) in the 810LP, and in the top models a separate power supply board with a toroidal transformer. The optional 820S external supply takes the idea further for the 610LP, 810LP and the North players: two toroidal transformers, pi filtering with 40,000 µF and dual 20 mH chokes per supply, and four stages of discrete M-R2S regulation.

Why it matters in a system

With a moving-coil cartridge at 60 to 70 dB of gain the phono stage is the noisiest link in most systems, and its noise floor sets how much of the groove you hear. Independent filtering stops stages from modulating one another through the supply, and the result is the very low noise MOON's phono stages are known for: 115 dBr at 40 dB gain on the 810LP, 112 dBr on the 610LP, 110 dBr on the 310LP. It also makes the units unusually insensitive to the quality of the mains.

What you may hear

Black silence between tracks even with a low-output moving coil, and the small details of a record, room sound, decays, the texture of a bow, that noise would otherwise bury. Michael Fremer's verdict on the 810LP: "the 810LP was dead quiet."

Lineage

Documented on the Evolution 850P preamplifier (CES 2011; 40 stages, per Stereophile's 2013 review). Carried into the phono range: 810LP (2012) and 610LP (24 stages each), 310LP (2 stages) and, as inductive DC filtering, the 110LP v2. The 820S external power supply extends the approach with M-R2S regulation.

Proof

Manufacturer specifications: 810LP signal-to-noise 115 dBr at 40 dB gain, THD 0.0008%; 610LP 112 dBr at 40 dB gain, THD 0.001%; 310LP 110 dBr at 40 dB gain; 110LP v2 104 dB at 40 dB gain with "Inductive DC Filtering for a significantly lower noise floor"; 850P "i 2 DCf (Independent Inductive DC Filtering)" with one inductor per IC, "40 stages in all"; 820S "M-R2S" regulation, four stages per supply, 40,000 µF and 2 × 20 mH chokes per supply. Stereophile (Brian Damkroger, 2013, 850P): "The power supply incorporates 40 examples of the unique filtering topology." Stereophile (Michael Fremer, Analog Corner, 2013, 810LP): "four stages of Simaudio's Moon Low Voltage (M-LoVo) DC regulation," "a claimed noise floor of –150dB relative to 1.0V, DC–100kHz" (manufacturer claim); "the 810LP was dead quiet."

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Signature technologySince 2011

M-Octave, M-Quattro and MDB vibration control

Floating suspensions and damping bases that isolate the audio circuitry from vibration, so the circuit is not turned into a microphone by the music it is playing. Read the deep diveClose

What it does

Electronic components are slightly microphonic: vibration from the loudspeakers, the floor or a spinning disc modulates their behavior and adds a smear to the signal. Simaudio addresses this mechanically. On the 850P preamplifier the entire audio board floats on an eight-point elastomeric suspension that Simaudio calls M-Octave, with the audio circuitry in its own chassis away from the power supply. The 810LP phono preamplifier mounts its board on a five-point gel-based suspension derived from M-Octave; the 260D CD transport sits its drive on M-Quattro, a four-point gel suspension; and the 891 introduced MDB, the MOON Damping Base, a thick aluminum base with gel decoupling and a thermal phase-change compound beneath the analog, phono and digital boards. The Bridges and North Bridges stacking legs carry the same thinking to the rack, with elastomer pads between components.

Why it matters in a system

The lower the signal level, the more vibration matters, which is why these measures appear first on preamplifiers, phono stages and disc transports. In a real room, with loudspeakers playing at realistic volume, a suspended circuit keeps its noise floor and its focus; a rigidly mounted one gives up a little of both.

What you may hear

Sharper focus and a quieter background at volume, and on the 260D a stability to the sound that owners often attribute to the transport rather than the disc. Simaudio's own description of the 850P's suspension is unusually direct: "complete microphonic annihilation."

Lineage

The eight-point floating suspension debuted on the Evolution 850P (CES 2011) and was named M-Octave. The 810LP (2012) adopted a five-point gel-based suspension "derived from our M-Octave technology, originally developed for our reference 850P"; the 260D CD transport uses the four-point M-Quattro; the 891 (2023) introduced MDB, the MOON Damping Base.

Proof

The Audio Beat (CES 2011): the 850P mounts "the entire audio circuit on an eight-point floating suspension." Stereophile (Brian Damkroger, 2013): "eight compliant feet, each made of an elastomeric material." Simaudio (850P page): "Suspension for complete microphonic annihilation"; (810LP page): "5-point gel-based floating suspension" "derived from our M-Octave technology, originally developed for our reference 850P Preamplifier"; (260D page): "M-Quattro gel-based 4-point floating suspension"; 891 user manual: MDB is "a mechanical decoupling system designed to suppress parasitic vibrations" (manufacturer claims). SoundStage! Ultra (Aron Garrecht, October 2024): MDB combines a thick aluminum base, a gel-based suspension and a thermal phase-change compound. What Hi-Fi? (3 May 2023): MDB offers "mechanical isolation to protect against unwanted micro-vibrations."

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Made in Canada

Hand-assembled in Boucherville, Québec

Every MOON component is designed, hand-assembled and tested in Simaudio's own factory in Boucherville, across the St. Lawrence from Montréal, as it has been since the company's founding in 1980. Read the deep diveClose

What it does

Simaudio has built its own products in Québec since Victor Sima founded the company in 1980. Under Jean Poulin, owner and chief executive for nearly two decades, the operation grew from a 3,000-square-foot shop to a 46,000-square-foot, vertically integrated factory in Boucherville, where engineering, assembly and quality control sit under one roof. When Poulin handed the company to three of its own people in 2013, their commitment was that MOON "will continue to be engineered and manufactured in-house, in Quebec." Boards are populated, chassis finished and every unit hand-assembled and measured before it leaves; a single 888 monoblock takes about a week to build.

Why it matters in a system

Keeping design and production together is how a small company controls quality at this level: the engineer who specified a matched set of transistors can walk to the bench where they are selected, and a change in a circuit can be made in production the same month. It is also what makes long-term service realistic. A MOON component bought today can go back to the people who built it, and the 10-year warranty program rests on that.

What you may hear

Consistency. Two 761s sound like two 761s, and the one you audition in Portland is built the same way as the one delivered to your home.

Lineage

Sima Electronics was founded in Québec in 1980 by Victor Sima; the company's own timeline places the Simaudio Ltd. name in 1990 and the first MOON Series in 1997. The facility grew from 3,000 to 46,000 square feet by 2013. All current MOON components are designed and hand-assembled in Boucherville, Québec.

Proof

Simaudio (About): "Independent since 1980"; products are "designed and hand-assembled in Boucherville, Québec, Canada," which keeps engineering, assembly and quality control "closely aligned"; "Built in Quebec. Made to last."; "more than 400 awards worldwide." The Absolute Sound (20 September 2013, change-of-ownership announcement): "For nearly two decades Jean Poulin has been owner and chief executive"; growth "from a basic 3,000 sq. ft. facility to a 46,000 sq. ft. vertically integrated operation"; "MOON products will continue to be engineered and manufactured in-house, in Quebec (Canada)." Stereophile (Michael Fremer, 2018, MOON 888): "it takes about a week to assemble one 888."

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Every MOON component we carry (18)

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Ownership

10-year warranty

Register a new MOON component within 30 days of purchase from an authorized dealer and the one-year standard warranty is replaced by up to ten years of coverage against manufacturing defects. Read the deep diveClose

What it does

In Canada and the United States every MOON component carries a one-year parts-and-labor warranty. With a validated registration completed within 30 days of purchase from an authorized MOON dealer, that limited warranty is replaced by an extended warranty of up to ten years against manufacturing defects. Mechanical parts, the laser transport, volume control and switches, are covered for three years under the extended program. The coverage is not transferable from one private owner to another, which is one reason a MOON component bought new, from a dealer, holds its value. Outside Canada and the United States the dealer or distributor sets the terms.

Why it matters in a system

A ten-year commitment is a statement about how the products are built and how long the company expects to support them, and it changes how you plan a system: a 641 or 791 bought today is a component you can build around for a decade, with Simaudio's own factory behind it. Ask Pearl Audio to help with registration when your component is delivered; the 30-day window starts at purchase.

What you may hear

Peace of mind is not audible, but a system you are not worried about is one you listen to more.

Lineage

Simaudio has offered extended coverage through its Product Registration Program for many years; the 30th-anniversary editions of the 600i and 750D in 2010 carried a 30-year warranty. Current terms (Canada and USA): one year standard, up to ten years with registration within 30 days, three years on mechanical parts.

Proof

Simaudio warranty page (Canada and U.S.A.): "The Standard Warranty is 1 year parts and labour"; with a validated registration the limited warranty is replaced by an extended warranty "of up to 10 years" against manufacturing defects, for products bought new from an authorized MOON dealer and "registered through us within 30 days following the date of purchase"; mechanical parts (laser transport, volume control, switches) three years; the extended warranty "is not transferable from a private party to another." Outside Canada and the U.S.A. the warranty is set by the dealer or distributor. Simaudio FAQ: "MOON products are backed by a 10-year warranty." Simaudio history: the 2010 30th-anniversary 600i and 750D carried a 30-year warranty.