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Mark of the Unicorn 308 Digital Interface

If your Mark of the Unicorn (MOTU) 2408-family DAW setup is anything like mine, you've already filled up most of its input and output connectors. When MOTU first announced the 308 last summer, my immediate reaction was, "Oh goody! Now I can connect more stuff to my system." It was only after I became more familiar with the 308 that I noticed even more interface possibilities it brought to my setup.

If your Mark of the Unicorn (MOTU) 2408-family DAW setup is anything like mine, you’ve already filled up most of its input and output connectors. When MOTU first announced the 308 last summer, my immediate reaction was, “Oh goody! Now I can connect more stuff to my system.” It was only after I became more familiar with the 308 that I noticed even more interface possibilities it brought to my setup.
Product PointsApplications: Project studios; recording studios

Key Features: Three eight channel I/O banks in TOSlink S/PDIF; coaxial S/PDIF and AES/EBU formats

Price: $995 with PCI-324 card; $695 without

Contact:Mark of the Unicorn at 617-576-2760.


+ Standalone or computer use

+ Interfaces with other MOTU I/Os


– Not 96 kHz-ready.

The Score: If you already own a MOTU hardware setup, the 308 provides features unavailable any other way. I use mine every day.
One of the best features of MOTU’s digital recording software is its ability to send so many signals to so many places – simultaneously – through creative bussing and employing of numerous auxiliary tracks. Engineers who were used to a large-format analog console likely received a rude awakening trying to apply routing concepts – originally developed in that world – to the virtual world of computer recording and mixing.

With the MOTU system, Digital Performer or AudioDesk and the 308, one can send various track pairs (or even virtual group mixes) out to external effects units or monitoring devices – completely within the digital domain-and return them to the computer just as easily.


The MOTU 308 is a single-rack-space-size chassis with 64 small LEDs and three switches on its front panel. It is capable of 16, 20 and 24-bit recording at 44.1 or 48 kHz. On the rear are eight S/PDIF-format TOSlink fiber-optic connectors, eight gold-plated S/PDIF coax RCA jacks, four female and four male XLR connectors for AES/EBU I/O, a pair of BNC jacks for word clock I/O, one AudioWire (much like FireWire) connector for interfacing with MOTU’s PCI-324 card and the customary IEC AC connector. For standalone use, one only needs the 308, but for computer control, connection to MOTU’s PCI-324 card (installed in an appropriate PCI slot within one’s Mac or PC) is necessary.

Many prospective purchasers of the 308 already own a MOTU 2408-family system interface and PCI-324 card, in which case the only necessary purchase is the 308 box itself. The PCI-324 card has three AudioWire inputs, so it is possible to configure a full single-card MOTU system with a 2408, a 24i and a 308 to achieve a system with 72 inputs and 50 outputs; easily routable to just about anything in both the outside and virtual worlds.

In use

Connecting the 308 into a MOTU system is simple. I ran its 15′ AudioWire cable to the PCI-324 card, which is located within my four-slot Magma expansion chassis (which is connected to my 300 MHz G3 PowerBook). I didn’t even have to run a separate house word clock input to the 308 because all members of the MOTU 2408 family automatically share the same clock and sample-accurate sync signals, regardless of their source.

I ran the most current MOTU installer CD and made sure I had the latest versions of the PCI Sound Manager, MAS and FreeMIDI drivers in my system. After connecting a few digital devices to the 308’s TOSlink and RCA jacks, and its XLR jacks to my Z-Systems Z-16.16 patchbay, I rebooted the PowerBook and got ready for the fun.

I launched MOTU’s PCI-324 console software application and pulled down its configure interface menu. Presto – there were now two interfaces recognized by the card: my original 2408 and the new 308 box. To test it quickly, I simply routed the signals from my 2408’s bank-A ADAT ODI inputs (originating from my Apogee AD-8000SE) to all three input banks of the 308.

I was immediately rewarded with a little light show; the 24 appropriate green LEDs on the 308 started dancing in time to my source audio. I selectively turned various pairs on and off in the PCI-324 console application, and watched the results on the 308, which behaved exactly as predicted.

Although I do not expect to use my 308 in standalone mode very often, I also tested that function. It was nice to be able to reverse left and right channels as I bounced various pairs of audio around the unit.

Working with the two front set and select panel buttons is similar to setting a digital wristwatch, and just about as easy. The 308 defaults to standalone mode only when powered up without the host computer being on – as long as it sees the PCI-324 card when it’s first turned on, it automatically enters PCI Mode, in which various pieces of MOTU software can be used to do extensive routing and bouncing among all the connected MOTU hardware interfaces.

Although this review is hardly the place for a course on Digital Performer’s extensive routing offerings, a couple of examples indicate the possibilities a MOTU 308 user might enjoy. Consider the total coolness of being able to send multiple, different mixes to different destinations within the digital domain. For example, one can send different cue mixes to different musicians, transmitted as digital data and received by one of the various headphone boxes with digital inputs currently available, such as units by M Audio, Lucid, Videoquip and others. Within Digital Performer, one simply routes audio tracks to individual buses, mixes the buses to various aux tracks and assigns each stereo virtual output to a different physical output on the 308 (or just as easily to analog outputs on a 1224). Very little CPU horsepower is consumed by such routing and mixing schemes and they certainly increase the flexibility of one’s MOTU workstation.

You don’t want to send different cue mixes? Fine, how’s about different stereo send mixes to different hardware effects boxes? The same principle applies here. Just set up the appropriate bus and aux routing within Digital Performer or AudioDesk, and you’re off and running.

Consider a setup I use every weekend, while taping airchecks of my favorite NPR and PRI radio shows for later listening. My favorite shows seem to air at the same time, so with four FM tuners connected to the analog inputs of my Apogee AD-8000, feeding my MOTU 2408’s ADAT-A input, I can route those four different radio signals to a different DAT recorder (via the 308’s TOSlink, RCA, or AES/EBU connectors) and simultaneously record some of them directly to hard disk. There is no other easy way to send the four different stereo digital outputs from an eight-channel device like the Apogee AD-8000 to different DAT machines, unless they all happen to have AES/EBU I/O. The 308 makes doing this a piece of cake.


I’m sure that if I owned an expensive large-format analog console – say an Amek 9098 – I’d probably never use all of its sends and returns at the same time. It’s very reassuring to know that, with the 308 as part of a MOTU workstation – one which also includes, perhaps, a 2408 and a 24i box – I’ll never run out of I/O possibilities in a computer recording and mixing setup.

As far as I know, this is the first time anyone could make such a statement about equipment priced within the reach of most musicians. With the expansion of MOTU’s hardware interface family by devices such as the 308, the concept of recording and mixing an entire project within a computer environment has finally reached full maturity. Thank you, MOTU!