m920 High Resolution Monitoring System

The m920 High Resolution Monitoring System - transparent, open and musical audio performance for discerning audio professionals and connoisseurs. For that moment when you fall back into the chair and the music coming through inhabits your being. In this world of endless distraction, the goal is to achieve limitless engagement. And that is what the m920 is designed to do. Whether you are mixing, mastering or simply listening - the resolution, detail and immediacy that occurs with the m920 at the center of your system will help pull you out of the din and in to the music.

The m920 stands on the shoulders of its predecessors then jumps to new territory in digital and analog audio performance. Using the latest 32Bit Sabre DAC technology, it delivers up to 384kHz PCM and 64x and 128x DSD playback. The m920 provides state of the art DAC performance in our award winning compact, do everything utility design. For home or studio, this is truly the ultimate, high resolution monitoring system.

Building on 15 years of experience designing reference playback equipment, the technology in the m920 is highly evolved and refined. Each time we set out to improve a design, the goals are always clear: Lower the distortion, improve the noise performance, lower the DAC's jitter, make it more reliable. Make it better. With the m920, we hit the all bullseyes. The new, world-class M Series 32-bit Sabre DAC provides an astonishing improvement in digital performance. Redesigned s-Lock PLL circuitry improves jitter rejection. DSD64 and DSD128 playback brings great musicality to digital recordings. Every performance and design element was considered and where improvements could be made, they were. This is truly pinnacle for high resolution playback. And best of all, its available now from your favorite Grace Design Dealer.

m920 system firmware version 1.3 (12/12/2014)

m920 firmware v 1.3 disables decoding and playback of DSD over PCM 'DoP' received via the m920 AES3 and S/PDIF. For 'DoP' operation, instal firmware version 1.2

m920 system firmware version 1.2 (9/29/2104)

m920 firmware release notes (pdf)

Mac (10.8 and above) USB DFU v1.0 (10/20/2014)

Owner's manual Rev B (pdf)

Setup Menu Quick Guide (pdf)

Windows USB Audio Class 2 Driver v2.23.0 (released 01/08/2014)


  • features
  • specs
  • computer setup help
  • video
  • Stereo analog inputs - balanced (+4dBu) XLR and unbalanced (-10dBv) RCA.
  • Ultra low distortion 32-bit /384khz Sabre DAC accepts stereo digital input source in AES3, S/PDIF, TOSLINK (optical) and USB formats with auto sample rate detection and digital de-emphasis filter
  • User configurable DAC filter response for PCM and DSD playback
  • USB for playback of up to 384kHz / 32 bit PCM as well as DSD64 and DSD128 playback via DoP
  • AES and S/PDIF playback of up to 192kHZ / 24bit PCM as well as DSD64 playback via DoP
  • New dual-stage wide lock range PLL for improved jitter rejection on non s-locked sources
  • Third generation s-Lock™ dual stage PLL (phase lock loop) circuitry for the ultimate in low jitter clocking and sonic integrity
  • Two sets of line level outputs provided via RCA (unbalanced) and ¼ TRS jacks (balanced) for connection to stereo monitors
  • RCA line outputs can be configured for variable or fixed dac output mode for operation as a standalone digital to analog converter
  • Front panel rotary encoder provides precision level control of both headphone and the line output levels. Level adjustments are made in 0.5dB steps within a 95dB range
  • 0.05dB channel level matching to ensure true stereo balance at any monitoring level
  • Large, white 7-segment display is used to show headphone and stereo main output levels
  • New X-feed (crossfeed) simulates the acoustics of a loudspeaker listening environment which can significantly improve imaging while reducing listening fatigue when using headphones. This feature employs carefully designed signal cross-feed, filtering and delay circuits to simulate hrtf (head related transfer functions)
  • High current transimpedance output amplifier design drives 8 ohm loads. The m920 was specifically designed with low impedance headphones in mind
  • Only the highest quality 0.5% metal film resistors are used throughout and there are no electrolytic capacitors in the signal path. Sealed gold contact relays are used for all signal switching
  • Infrared remote control for level control, left/right balance, mute and more when using the optional remote control unit
  • Apple IR remote control is supported with optional pairing
  • USB firmware upgradability
  • 5 Year transferable warranty on parts and labor




Asynchronous Audio

The asynchronous mode USB converter in the m920 represents a significant improvement over any previous type of USB DAC. Previously, a USB DAC worked under standard adaptive mode USB audio, which means the DAC’s clock would have to sync to the non-audio related computer USB buss master clock. As you can imagine, the computer has a lot else to do, so the incoming clock signal to which the DAC’s clock would have to sync was not ideal and would result in unwanted jitter.

With asynchronous mode USB, the USB DAC becomes the master to which the computer’s USB buss gets synced. So the computer is now synced to a crystal-based audio clock signal and the system works with dramatically lower jitter. No phase-lock loop or sample rate conversion is necessary, which means bit-perfect playback from a computer with zero interface induced jitter. In addition, the USB port ground is completely isolated from the m920 audio ground. This eliminates the possibility of noisy computer grounds inducing any noise or impurity in the m920 audio circuits.

Computer Audio Requirements

Regardless of the type of computer you will use to playback audio from, it must have at least one available USB port. The m920 ships with a standard USB type A to type B mini cable. The type A connector plugs in to the computer and the type B mini connector to the USB m920 input.

The m920’s asynchronous mode USB DAC supports standard driverless operation on MAC to 96kHz in USB class 1 (U1) mode and 384kHz in USB class 2 (U2) mode and on PC to 96kHz in USB class 1 (U1) mode. For sampling rates above 96kHz, PC users will need to set their unit to U2 mode and download and install a free driver on their computer, found here - Windows USB Audio Class 2 Driver v2.23.0

Driverless operation basically means ‘plug and play’. The m920 will automatically show up in your computer’s list of supported audio devices as ‘Grace Audio Device’. In most cases, simply choose that as your audio playback device and the system will work. Different operating systems and audio players will pose their own set of complications in setting up the m920 as the audio playback device. In the event that ‘plug and play’ operation does not occur, you will need to look at some specific setup variables for your player and OS. In this case, we will direct you to a very well written and comprehensive document by our friend and colleague Charles Hanson from Ayre Acoustics. http://www.ayre.com/usb.htm This is an invaluable resource for computer/USB audio setup information for most current operating systems, and we strongly urge you to familiarize yourself with the information pertaining to your specific OS.

In the event that you have any setup issues which aren’t addressed by these resources, feel from to contact us directly at 303.823.8100 M - Friday 9 – 5 MST, or you can email our service department - service@gracedesign.com.