David Bowles finds out whether this new device deserves to be described as ‘a vital addition to any modern audio production environment.’
I’ve always been a fan of Grace Design mic preamps, and have used them often over the years for commercial projects. The company’s m801 eight-channel mic pres were already a part of many established recording studios; later it offered the m802 with remote control and an optional A/D module. With the m802, this still required one more unit to transport and set up for location recordings: a D/A to monitor DAW mixes. Many of the 1RU audio interfaces currently on the market only provide two to four channels of mic preamps, and some observed these preamps were not of the same quality as standalone mic pres. Units with more mic pres expanded to 2RU were quite expensive at the time they were released and the A/D quality varied considerably. My need was for a 1RU unit for simple recording projects and live concert recordings of up to eight channels, so I wouldn’t have to disconnect my 24-channel unit from my studio setup.
Grace Design has now fulfilled this niche with the m108, a 1RU audio interface with eight channels of high-quality mic preamps, A/D conversion and two channels of D/A conversion for their headphone amplifier. Mic inputs are via XLR, with the first two channels switching automatically when high-impedance instrument inputs are plugged into the front of the unit. In the rear, mic pre outputs are mirrored via two DB25 outputs (for analogue and AES respectively), as well as two ADAT outputs. In normal operation, ADAT transmits eight channels of 44.1/48kHz audio out of each of these outputs; in SMUX mode (ADAT 88.2 and 96kHz) channels 1-4 are assigned to ADAT output 1 and 5-8 output 2. Otherwise, sampling rates go up to 192kHz, with extensive clocking options. Interfacing with a PC or Mac is done via USB2.
You’ve got options
Furthermore, an “option slot” in the rear provides two added-cost choices at present. The first provides Dante AoIP (audio-over-iP), with primary and secondary gigabit Ethernet outlets. A short Ethernet “jumper” cable allows both Dante and Grace’s remote control to operate using the same cable.
The second option card is called Control Room Output: this provides two analogue TRS outputs for driving monitors or headphone distribution amps (this was not available at the time of writing). However, both options cannot be used together, nor can the DAW outputs be routed to the DB25 analogue output. I wanted to monitor 5.1 and stereo mixes from my DAW, but can only monitor a headphone feed. Perhaps this can be addressed in the future?
The build quality is what one would expect from Grace Design: simple, functional and solid. The unit is very light in weight, compared to the m801/802. This makes for easy permanent mounting in catwalks and attic spaces, since Ethernet and the Dante option card enables full remote control. On the front of the unit are two large control knobs, with a wide OLED display window in between them. Separate buttons are clearly labelled for phantom power, polarity inversion, pan and setup. A headphone monitor mix can be created from the eight mic inputs – in this case the first three buttons function as mute, solo and pan respectively. The power switch is also on the front of the unit. While this is practical, the switch can be toggled too easily. I prefer recessed switches which require more pressure to toggle on and off. Grace Design’s documentation explains everything very clearly, including the added functions of their two option cards.
The OLED display window is designed to be read from a distance, with large numerals on either side to indicate mic pre and headphone level. In between, a graphic display of each channel indicates channel number, a level meter, icons for phantom power, Hi-Z input, clipping, polarity inversion, gain level and ribbon mode. On the right side of the window one can see clock rate, source and clock output. In monitor mix mode, one can see channel number/name, level, pan, solo/mute, mix level, master level, monitor source and headphone source. In this mode, the user scrolls left to right, as there is more information than can be displayed in a single window. Finally, in Setup mode, there are 16 options, including display brightness/auto dim and even one’s choice of headphone level when starting up.
Control of the unit can also be done via Ethernet, serial (RS422 or RS485, for Grace Design’s m802RCU remote control), and MIDI I/O. With Ethernet, one can use a Chrome, Safari or Firefox browser (after entering the IP address), or the included standalone Remote Control Application. Presets can be saved and recalled easily to one’s recording computer, which makes switching between projects easy and consistent. Wordclock I/O and auto-switching IEC inlet complete the well-equipped rear panel.
There is also another component included in the installation: a USB Audio Control Panel (not described in early versions of their documentation). This allows the user to access “USB Streaming Mode” (latency) and set ASIO buffer size. My only criticism of the latency settings is that they are descriptive rather than specific (i.e. “Relaxed”, “Extra Safe”).
Setting up the m108 was straightforward. On my recording laptop, I use static IP. Once I assigned an address to the m108 it was easy to ‘locate’ the unit, control the settings and save a preset. As the mic inputs are XLR, I didn’t need to pack a breakout loom.
Over the next week, I recorded two chamber orchestras in concert at 192kHz – one performing on period instruments, and one on modern instruments. The concerts were done in the same two acoustic spaces in which I’ve recorded these groups for quite a few years.
The quality of mic preamps and A/D alike matched my DAD AX32 (and exceeded that of the Prism Orpheus I had previously used as my ‘second rig’). The recordings were clear and detailed without being harsh (in spite of the dryness of both concert halls). The headphone amp drove my Sennheiser HD800’s easily. The next time I record these groups I’ll be ready to record much sooner, by recalling the saved presets.
I’m happy to add the Grace m108 to my rig, not only for projects of up to eight channels, but to route the AES outputs to my DAD AX32 (thus adding another eight channels to that unit).
- Eight channels of ‘transparent, musical? mic preamplification’
- ‘State-of-the-art’ 192kHz A/D conversion
- Reference DAC and headphone amplifier
- Combination RS 485/422 serial/MIDI ports
- High contrast, wide viewing angle OLED display
David Bowles is a freelance audio engineer specialising in recordings of acoustic music in surround-sound and 3D audio. He guest lectures at New York University’s Steinhardt School Tonmeister seminar, resides near San Francisco, and likes good wine and bad puns.