Looking for a FireWire interface with multiple mic preamps and ADAT connectivity? MOTU 8Pre. Already have an interface and want to take advantage of those tempting ADAT ports? MOTU 8Pre. This unit from the well-known Mark of the Unicorn can work either as a FireWire interface or as an optical converter.
In the first role, it's an interface that can operate at 96 kHz/24-bit and offers 8 mic/instrument preamps, each with a pad, LED meter and phantom power on every channel. In addition, the ADAT ports can be used simultaneously to get 8 more channels of input and output.
In the second role, the 8Pre acts as a mic preamp and provides optical conversion of the eight analog input channels, to be sent over the Toslink cable at sample rates of 44.1 or 48 kHz in normal mode, and up to 88.2 or 96 kHz in 2x mode.
With simple controls that interact in different ways with the LED section, the 8Pre turns out to be a powerful and easy-to-use tool.
The Controls
The front panel holds the controls for the eight mic preamps. Each one has a gain knob for input, a 20 dB pad and independent 48 V phantom power.
The manual states that the gain is approximately 40 dB, though no further details are given. To help set this gain, each preamp has an LED meter (five segments) that shows the input signal level.
The stereo headphone jack is also on the front panel (Phones), and it can be used as an independent output when the unit is used as an interface, in which case it becomes an unbalanced stereo output.
Next to this output is the knob labeled Volume, which also works as a push button and handles several jobs, notably controlling the signal level at the main output (Main Out) and the headphone output, selecting the sample rate (when the unit runs on its own clock), and setting the protocol used on the optical ports.
On the rear panel are the eight XLR/TRS combo connectors for feeding analog signals into the unit, which accept balanced and unbalanced signals. Next to them are the main output connectors (balanced TRS), two FireWire ports and the MIDI I/O connections.
The two pairs of optical ports can operate at 44.1/48 kHz (1x mode) and 88.2/96 kHz (2x mode). In the first case, the two upper ports carry the eight channels of audio input and output, and the lower Out port mirrors the upper one, so the same information can be sent to two different devices.
When operating in 2x mode, the two upper ports carry I/O for channels 1-4 and the two lower ones carry channels 5-8. Two protocols are supported in this mode: the generic SMUX and a MOTU proprietary one.
Working as an Optical Converter
Integrating the 8Pre through the ADAT ports couldn't have been easier. A few seconds after connecting the unit to a Digi 002 Rack, the 8Pre had switched to converter mode and picked up the sample rate used in the session (48 kHz). After setting Pro Tools' sync to ADAT mode, the MOTU's eight preamps were ready to use.
Using this unit and a laptop (2 GHz Intel Core 2 Duo and 2 GB of 667 MHz DDR II RAM), we recorded a small band made up of guitar, bass and drums. Seven mics were used on the drums and two on the guitar amp, and the bass was recorded direct (two of the Digi's preamps were used for the toms).
It should be said that setting levels on the 8Pre was made far easier by the LED meters, since some converters of this type don't include them, and that counts in MOTU's favor.
Working as an Interface
Integrating it as an interface took a little longer. As the manual instructs, before connecting the interface to the computer we installed the drivers from the installation CD.
However, when we plugged in the interface, Windows didn't recognize the device. It was a matter of telling the operating system to look in the CD-ROM drive, and the problem was solved.
Apart from that small hiccup, the unit performed perfectly, delivering eight valuable mic preamps to Cubase SX 2 and leaving the door open to expand the system in the future through the free optical ports.
Since the installation CD includes ASIO, WDM, MME and GSIF drivers, compatibility with other programs such as Nuendo, Sonar, Soundforge or GigaStudio is assured.
Cue Mix DSP
The Cue Mix DSP application is a virtual mixer that lets you route any input of the 8Pre to any output, independently of the DAW's mix.
It uses its own DSP, so this mixer puts no load on the computer's CPU and brings latency down to practically zero, similar to what you find on digital mixing consoles. In addition, Cue Mix can create up to four different mixes, which is very useful for providing different headphone mixes to different musicians.
Conclusions
Although the technical specs of the mic preamps aren't included, I'd venture to say these preamps are quieter than those found on other interfaces.
The knobs offer a clean, noise-free sweep, and at maximum gain the self-noise is quite low. It should be noted, however, that the eight channels weren't identical. On this unit, preamps five and eight were slightly (very slightly) noisier than the others at that maximum gain setting.
If you have an interface with several mic preamps, you'll probably find that yours does this too, and it's simply useful to know that if you're going to record sources that need large amounts of gain, it may be best to steer clear of those “noisy” channels.
As for operation, the unit stands out especially, largely thanks to the large number of visual indicators it has. Other converters of this type don't have five-segment meters for each input, and that's worth noting.
In short, it's an easy-to-operate unit that, as a converter, offers quality preamps and simple integration and, as an interface, has the same preamps and can be used with a large number of different DAWs. Can anyone top that?
