Continuing our look at the DiGiGrid Desktop Range, the natural partner to the excellent DiGiGrid D is the DiGiGrid M. A 2 in, 2 out Soundgrid IO which, having tried all the boxes in this range I have to say is my favourite.

The M is one of three members of the Desktop family which follows the “blue cube” form factor. I will put my hands up straight away and confess that because of the small (though in the flesh they are larger than I imagined) and friendly appearance I expected a lightweight, physically unimpressive box from a build quality point of view but, as I admitted in my review of the DiGiGrid D, these are reassuringly heavy, solid, cast metal boxes with quality pots and switches. The professional quality build is apparent in the all metal, nutted jack sockets and Neutrik XLR, all secured to the metal casework rather than a fragile circuit board.

Connectors And Layout 

The front panel carries the analogue IO. A 1/4" TRS Hi Z/line input and an XLR mic/line input share this space with a 1/4’ TRS headphone socket. The black graphics clearly indicate what goes where and although the word “Mix” is evident on the mix buttons I rather like the use of graphics to convey the important information rather than tying the hardware to a specific language. I’m sure this use of graphics is partly responsible for my aforementioned assumptions about the market at which this hardware was aimed. The whole package works and I can see some very clear thinking has gone into the design.

Network IO

The M is a combined input-output device and as an AoIP interface, connecting as it does to Soundgrid networks via CAT5e/6, this is precisely the kind of small, low channel count network node I was describing in my comment piece on the potential advantages offered by AoIP in decentralising audio systems by, instead of a group of musicians connecting to a single, large, high channel count interface, they each use a small networkable interface with a complement of inputs and outputs appropriate to their needs. A combined single-mix headphone amplifier combined with a high-quality mic preamp and DI covers a significant proportion of tracking scenarios with extra IO allocated as necessary.

The slideshow above shows the simplest possible setup using an M and a host computer. The setup process is as simple as connecting the M to the host via CAT5/6 and hitting Auto Config in the free SoundGrid Studio Software. The M can be powered via the supplied PSU or without the PSU if connected via a suitable PoE switch. DiGiGrid manufacture the S another member of the desktop range which is a 5 port PoE switch suitable for powering the Desktop range.

The size of the desktop range can be seen here. The meters surrounding the big knob on the top show the level going to the headphones and usefully are post fade so they give some indication of the level in the cans, though as there is no pointer on the knob itself, when there is no signal present it isn't apparent how loud your headphones are. After a couple of "surprises' it becomes second nature to turn it down before putting the headphones on!

Hardware Monitoring And Lots Of Gain

The Mic and Hi Z inputs can both be monitored at zero latency by engaging the Mix switches. This routes the input directly to the output in hardware. This could be improved by providing a variable mix control rather than a switch as to balance the input being hardware-monitored against the rest of the track it can become necessary to adjust the level of the track being sent from the DAW as there is no level control other than the input gain. 

The star of the show has to be the mic preamp, which offers 70dB of clean gain, I'll just repeat that ... 70dB! I've been frustrated by too many cheap (and some not so cheap) interface preamps with too little gain or too much noise to drive a passive ribbon or a dynamic on quieter sources not to draw attention to this preamp. This hardware monitoring is there to alleviate hardware buffer latency in the DAW rather than latency induced by the Soundgrid network, people are understandably concerned about latency in AoIP but the latency introduced by Soundgrid itself is to all intents and purposes negligible.  

Features And Specs

• 9cm cubed in high-grade aluminium extrusion
• 96KHz recording and headphone monitoring
• 2 inputs / 2 outputs / 48V Phantom / high pass filter and dedicated metering
• Mic Input - 0 - 70dB of Gain
• HPF - 18dB/Oct @ 100Hz
• Hi Z/Line - +6 - +30dB of Gain
• Headphone Output Minimum Impedance - 16 Ohms
• Analogue control path
• Connects to the SoundGrid network via a single Ethernet cable (Cat 5e/Cat 6)
• Optional stand mount adaptor for maximum flexibility of placement
• Stand-alone or integrate into larger DiGiGrid Advanced Audio Networks

Lots Of Little (Boxes)

I like this box and in a typical location tracking situation for a band, I have found it to be ideal for everyone apart from the drummer who needs rather more IO, which can be provided in the form of one of the excellent larger DiGiGrid boxes such as the IOS or by combining Desktop interfaces. The possibilities for flexible use of temporary tracking spaces, particularly spaces with installed data cabling are very tempting and I can think of many, many tracking jobs which would be improved immensely with a bag of DiGiGrid Ms.