We take an in-depth look at MOTU's most affordable Firewire audio interface yet.
There was a time not so long ago when Firewire audio interfaces were what you looked at only if you had a bit of money to spend. If you didn't, then your choice was limited to USB-based models. Now, though, while a fundamental price division between Firewire and USB remains, the actual prices of both have fallen, making Firewire an affordable proposition even for first-time interface buyers.
So why would you want a Firewire interface? Most importantly, the bandwidth of the Firewire 400 protocol (also known as IEEE 1394) is enough to support dozens of simultaneous audio channels, even at high sample rates. There are practical advantages too: most Firewire interfaces (and other Firewire devices) have two Firewire sockets, making it easy to daisy-chain additional interfaces, hard drives, and even powered plug-in systems like TC's Powercore or Focusrite's Liquid Mix.
MOTU's new 8Pre joins the ranks of Firewire interfaces towards the affordable end of the market — and at a recommended price of £495, it is MOTU's most affordable Firewire model. In a way, though, it's also MOTU's most specialised interface, with a feature set that seems to have been carefully chosen to provide maximum bang for the buck. Most notably, it does duty as both a Firewire audio (and MIDI) interface when attached to a computer, and as a stand-alone, 8-channel analogue-to-digital converter when it's not.
The 8Pre is a mains-powered, 1U-high 19-inch rackmountable unit that follows the styling and design cues of some other well-known interfaces in MOTU's range, such as the 828MkII and 2408MkIII. It feels nicely put together, with a metal outer casing and plastic front and rear panels, but the small metal toggle switches on the front panel are mounted on an internal circuit board rather than secured directly to the casework, so they do move a little in use. The same is true for some of the rear-panel connections, although the XLR/quarter-inch jack combo sockets, with their push-to-release levers, are case mounted and should be able to withstand a fair bit of wear.
The analogue connections are very straightforward. There are eight 'combo' XLR/quarter-inch analogue inputs on the rear panel, catering for mics, guitars and line-level sources, balanced or unbalanced. On the front panel, each channel has its own 48V phantom power switch, a trim knob with a 40dB range, and a 20dB pad, making maximum available gain of 60dB. Back at the rear panel again, two balanced line-level outputs are clearly intended for driving an amp or active monitors, and there's a separate front-panel headphone output. A single digital rotary encoder next to this controls headphone and main output volume level separately — you push it to switch from one to another, so for many typical project studio setups the 8Pre will not be reliant on additional monitoring controller hardware.
Digital connections come in the form of ADAT optical in and out, offering 8-channel operation at all available sample rates. The higher '2x' sample rates are handled by the 8Pre having two ADAT optical sockets for both input and output — the upper sockets for channels one to four and the lower ones for channels five to eight. This configuration conforms to industry standard S/MUX, providing compatibility with third-party equipment. For high sample-rate optical connection to other MOTU gear, the 8Pre has to be switched into a proprietary 'Type 2' mode. It's not clear why this is necessary, but since it works reliably it's not really an issue.
The 8Pre also sports two 5-pin DIN MIDI sockets, offering a simple 16-channel 1-in/1-out connection. When used with MOTU's own Digital Performer workstation software, MIDI timing is sample accurate. Rounding out the rear panel connections are two 6-pin Firewire sockets and an IEC power inlet for a standard mains lead.
Finally, at the far right-hand side of the front panel there's a display section. This consists of eight five-stage LED level meters indicating signal levels of -42, -24, -6, -3 and -1 dBFS for each of the analogue inputs. When adjusting main out or headphone volume these are temporarily suspended, and instead a horizontal row of LEDs roughly indicates the level being set. To the right of the meters a further eight LEDs are dedicated to displaying the 8Pre's basic settings, such as whether it's operating in interface or converter mode, the current sample rate, and whether the optical inputs are enabled. When the 8Pre is working in stand-alone converter mode, pushing and holding the volume knob for three seconds allows clock and optical settings to be dialled in.
As well as the main unit itself, purchasers of the 8Pre also get a real, printed manual which deals with all aspects of installation and use for both Mac and PC applications. A CD containing drivers is also provided, and Mac users can choose to install a bundled audio application, Audio Desk, which is a cut-down version of MOTU's Digital Performer. As expected, a mains lead and a fairly long Firewire lead are also provided.
As the metering section implies, the 8Pre can operate at a sample rate of 44.1, 48, 88.2 or 96kHz, and provide its own internal clock signal or synchronise to an incoming ADAT optical signal.
What the front panel doesn't hint at are the internal routing and low-latency monitoring facilities. Basically, up to four independent mixes of the eight analogue inputs and eight ADAT optical inputs can be created and routed (with near-zero latency) to the main outputs, the headphone socket (as a separate, discrete pair of outputs) or the eight ADAT optical outputs. All this is controlled from the computer with the included MOTU Cue Mix Console application.
There's another 'hidden' feature in the form of SMPTE sync. Again, in conjunction with an included application, MOTU SMPTE Setup, the 8Pre allows a sequencing application (such as MOTU's own Digital Performer, or any sequencer that supports ASIO2 sample-accurate sync) to slave to a timecode signal on any analogue input. The same application can also generate (or regenerate) SMPTE timecode via any analogue output.
If you want to use the 8Pre with a Mac you'll need at least a G3 running OS 10.3.9 or later. For the PC the minimum requirement is a 1GHz Pentium running Windows XP. As might be expected, Mac compatibility is provided with Core Audio and Core MIDI drivers, whilst Windows users are provided with ASIO, WDM and GSIF drivers, providing compatibility with Cubase, Nuendo, Sonar and Gigastudio amongst others.
MOTU don't publish any specifications for the 8Pre's analogue circuitry, such as frequency response or signal-to-noise ratio. While it might be nice to know these things, it could be argued that exact figures are almost meaningless to the typical user the 8Pre is aimed at. In any case, modern digital electronics design almost always ensures that signal-to-noise ratio and bandwidth are no longer the key concerns for the performance of an audio interface.
I did have a quick peek inside the 8Pre, though, and noticed a few points of interest. Prominent on the single main board are the analogue-to-digital converters — the same AKM5385 chips as used in the Mackie Onyx 400F and RME Fireface 800. Digital-to-analogue conversion is handled by AKM4382 chips. These AKM converters are well respected, and indeed are amongst the best available at this price point. Although the 8Pre offers sample rates up to a maximum of 96kHz, it's interesting to note that both the 5385 and 4382 converters are actually capable of supporting sample rates of 192kHz.
Getting the 8Pre up and running was very straightforward. I installed the MOTU Universal Audio Install package on to my Macbook, restarted and, after connecting and powering up the 8Pre, the MOTU Audio Setup application booted up to confirm settings on the interface.
Since the 8Pre majors on its microphone inputs and abilities as a stand-alone converter, it only seemed right to start with some listening tests, to try to judge subjective performance. To give some perspective and comparison I was able to draw on a number of other interfaces and mic preamps. These included MOTU Traveller, Ultralite and 896HD interfaces, and outboard mic preamps by DAV Electronics (a Broadhurst Gardens No. 2) and ART (a valve-based Digital MPA).
Photo: Mark EwingMaking some recordings of piano, guitar and percussion, using a pair of Schoeps CMC66 mics and a pair of Rode NT2As, first impressions of the 8Pre were very positive. Mic preamp noise is impressively low, and the trim knobs allow quite fine adjustment even towards the top of their gain range. They're certainly better in this respect than those of the 896HD, which cram too much gain change into the last few degrees of the knob's travel, and can crackle a little when adjusted too. In terms of tonal balance, I could not distinguish the 8Pre from any of the other MOTU interfaces — all had a likeable, 'sweet' quality characterised by a smooth-sounding and apparently very well controlled treble, with no harshness.
Bringing in the outboard preamps (of which two channels cost about the same as the 8Pre!) and sending their outputs to the 8Pre's line inputs gave some useful perspective. Unsurprisingly, the DAV preamps had a markedly more open quality and captured more detail, but although different they didn't put the MOTU to shame — you'd still make the 8Pre the first choice for some sources. Interestingly, there was not a great deal to choose between the ART and MOTU preamps; despite obvious design differences, both shared a similar warm and smooth sound, with the ART getting the edge thanks to its slightly more pleasing mid-range.
At the higher sample rates, the MOTU's sound changed almost imperceptibly — perhaps just becoming slightly leaner and exhibiting some additional detail. As I've experienced with other interfaces, there was not always a wholesale improvement in going from (for example) 44.1 to 96kHz. I felt piano recorded through the 8Pre sounded minutely better at the lower rates, but acoustic guitar was slightly nicer at the higher rates. You pays your money (or should that be disk space?)...
To cut a long story short, then, the 8Pre's preamps sound good, and have a bit of character to boot. There's a touch of congestion in the mid-range that might be revealed with very complex sources (such as full orchestra or choirs), and there was perhaps not the sense of quickness and impact with transient-rich sources that the best preamp designs can communicate. But the cost and price-performance ratio of the 8Pre should not be forgotten here — £495 for eight mic preamps, and a whole lot more besides, is pretty good going.
In other tests I also found the performance with DI'd guitar and bass to be good — clean and full-bodied — and the digital connections and MIDI worked as expected.
I enjoyed my time with the 8Pre. Fundamentally it's a very straightforward bit of gear which has clearly sacrificed a few luxuries (like multiple outputs, for example) in the name of affordability. However, what's left is nicely done — eight mic pres can get you in and out of a lot of recording challenges, the front-panel metering is useful, and the separate headphone and main out volume controls are worth their weight in gold if you use active monitors. I'm also glad that MOTU dispensed with extra front-panel controls (which the likes of the Traveller and 828MkII have) for configuring Cue Mix monitoring, as this is much more elegantly controlled from the computer anyway.
So who is the 8Pre aimed at? Aside from first-time interface buyers, who get a lot for their money (and the reassurance that it should remain a useful piece of kit even if they subsequently buy a more complex interface) it will also be of interest to existing MOTU interface owners, as it compliments an existing Cue Mix setup in a useful way. If you connect an 8Pre to another MOTU interface (Firewire or PCI-based) via the ADAT optical link, it appears as an additional eight inputs on that interface, and can be incorporated seamlessly into its four Cue Mix busses. But when you need to use the 8Pre by itself — on a location recording, for example — it's ready to go as a self-contained interface.
The 8Pre will also, of course, go head to head with other 8-channel ADAT-equipped preamps already on the market. Compared to many interfaces, its feature set is spartan, but it undercuts the majority of direct competition in terms of price.
Talking of competitors, there are surprisingly few Firewire interfaces with a similar feature set to the 8Pre. The likes of the Mackie Onyx 400F and Tascam FW1804 have only four mic preamps, while the slightly cheaper Presonus Firepod, despite having eight analogue outputs, has no ADAT interfacing or metering. The closest competitors are Focusrite's Saffire Pro and the Presonus Firestudio, which both have eight analogue outputs, more extensive digital connections and some extra bells and whistles here and there. Neither have front-panel metering, though, and both are more expensive.
To sum up, then, the 8Pre is an attractive and affordable option for a range of users. Its most obvious omissions are the lack of more than two line outputs, S/PDIF or AES stereo digital connections, and Word Clock synchronisation. However, some or all of these could be added by supplementing an 8Pre with another MOTU interface at some point down the line.
These considerations apart, I can't really think of anything to criticise! Some sort of bundled sequencing package for PC users would, of course, be nice, and perhaps some finer metering resolution could have been advantageous in a few instances when the 8Pre is being used as a stand-alone converter and preamp. But for the money this is a well thought-out interface that offers a nice balance of simplicity and flexibility, and one which should easily earn its keep, and sometimes prove invaluable, in many different kinds of studio. .