The Grace Design m905 is a mastering-grade stereo monitor controller designed to deliver uncompromised transparency, flexibility, and accuracy for critical listening environments. It is available in two configurations, the Grace Design m905 analogue version and the m905 digital version which includes an integrated high-performance DAC. The system consists of a 2U rackmount mainframe and a separate remote control unit connected by a single robust cable, ensuring the separation of analogue and digital circuits from user control for the highest possible audio performance.
The Grace Design m905 offers three balanced analogue stereo inputs and a wide range of digital inputs including AES3, S/PDIF coaxial, S/PDIF optical, and asynchronous USB 2.0 for direct computer playback. The internal DAC supports PCM audio up to 384kHz and native DSD64 and DSD128 via DoP streams. All source switching is performed using gold-contact relays to maintain absolute sonic integrity. Input levels can be calibrated individually for precise level matching between sources.
The monitoring section features two stereo speaker outputs and a dedicated subwoofer output. Each output includes independent level trims and switching control. Subwoofer integration is highly flexible, allowing assignment to either or both speaker pairs. Relay-controlled analogue level attenuation ensures consistent and precise channel balance at all volume levels.
The Grace Design m905 provides a full suite of monitor control functions including mono summing, channel solo, channel mute, channel swap, and polarity inversion. An internal SPL meter with microphone calibration input allows precise alignment of monitoring levels to professional standards. Measurement microphone calibration can be performed easily through the system menu.
The headphone monitoring system within the Grace Design m905 operates independently from the main speaker output. It features its own dedicated DAC and audiophile-grade headphone amplifier capable of delivering over 500mW into 32Ω loads with extremely low distortion and wide bandwidth. Headphone volume control is independent from speaker volume, allowing simultaneous use without compromise.
The Grace Design m905’s asynchronous USB audio interface allows high-resolution playback from computers with no driver installation required for Mac OS X and easy driver installation for Windows systems. The system accepts PCM streams up to 384kHz and DSD over PCM (DoP).
User-definable presets allow fast recall of frequently used source and output configurations. All settings are stored automatically and are recalled on system startup, ensuring a consistent workflow. The system is powered by an internal universal power supply compatible with 100–240V AC, 50–60Hz operation.
The Grace Design m905 is engineered with meticulous attention to circuit design, mechanical layout, and user interface functionality, providing mastering engineers, mixers, and high-end audio professionals with the ultimate stereo monitor control solution.
Features
- Analog inputs: unbalanced (standard or optional RIAA phono input), balanced (second pair balanced available on m905 Analog), CUE, talkback mic
- Digital inputs: 2 x AES3 (single or dual-wire), 1 x S/PDIF, 1 x TOSLINK, ADAT (selectable in 4 pairs or 2 pairs in S/MUX), USB, DSD128 (5.6448MHz)
- Audio circuitry designed for completely transparent and musical playback performance
- Asynchronous Class 2 USB playback supporting up to 24-bit/192kHz
- Mastering-quality DAC circuitry with configurable de-emphasis filtering
- s-lock dual-stage Phase Lock Loop for ultra-low jitter clock regeneration
- Hybrid RCU with hardware switches, large level encoder and graphical LCD
- LCD display showing input, level, output, SPL and DAC status plus full calibration menu
- RCU includes built-in microphone for talkback and onboard SPL meter
- SPL meter featuring level, peak, fast and slow modes, A and C weighting
- Precision 0.5dB step level control for speakers and headphones
- Reference headphone amplifier circuitry with outputs on both RCU and ACU
- Dedicated mono, dim, mute and sub mute switches
- Digital loop-through outputs configurable to pass incoming digital signals or act as digital speaker output when monitoring digital PCM sources
- Mono mode selectable between L+R summed, L only in both channels, or R only in both channels
- L solo, R solo, L–R and sub solo modes available
- Three available stereo speaker outputs with two assignable mono sub outputs or a single stereo sub output
- Multi-mode SUB/DAC/METER output
- SUB out mode for stereo or multiple mono subwoofer outputs
- DAC out mode for fixed DAC output fed by selected digital input
- METER out mode fed by selected input signal (digital or analogue) configurable with a fixed level or to follow monitor level
- Detachable RCU tilt base
