Until now, if you wanted multi-channel or high-resolution audio I/O in a hot-swappable external interface, Firewire was the only way to go. Edirol's UA1000 offers an alternative, using the Hi-Speed USB 2.0 protocol that is standard on nearly all new PCs.
When USB ports first appeared on PCs and Macs, soundcard manufacturers must have breathed a collective sigh of relief, thinking that tech support calls relating to PCI card installation would soon be over. The ensuing spate of teething troubles, due partly to incompatibilities with the wide range of USB Universal Host Controller chips to be found on PC motherboards, must have rather spoiled their enjoyment, but these have now largely been resolved, leaving USB an extremely easy way to add both MIDI and audio interfacing to computers without opening them up. The only remaining fly in the ointment is that the original USB version 1.1 bandwidth of 12Mbps isn't large enough to support 24-bit/96kHz stereo audio in full-duplex mode (recording while playing back). However, the more recent USB version 2.0 spec also supports 'USB Hi-Speed' devices with its 480Mbps bandwidth, and looks set to remove such limitations once and for all.
Although USB 2.0 ports have appeared on many new PCs and Macs during the last 18 months, there have been very few peripherals to fully take advantage of them until now. Edirol's new UA1000 is the world's first Hi-Speed USB audio interface, supporting up to 10 simultaneous inputs and outputs in full-duplex mode, and it's crammed with useful features, offering a comprehensive selection of mic, guitar, and line inputs, support on the digital front for S/PDIF optical and co-axial, eight-channel ADAT, word clock, and MIDI I/O.
The UA1000's 1U rackmount case is bristling with sockets, rotary knobs, switches and indicators, and features a striking metallic blue front panel that looks like milled aluminium, but is in fact moulded. The first four inputs have front-panel Neutrik Combi sockets with both the outer XLR and inner TRS jack supporting balanced and unbalanced signals. These inputs feature high-quality analogue preamps equivalent to those in Roland's VS2480. Each of these four inputs has its own rotary Sensitivity control, while input pairs 1/2 and 3/4 each have the option of +48 Volt phantom power for XLR balanced mic use, a 20dB pad to accommodate higher signal levels, and an LED indicator which illuminates green when an input signal is detected, and red when signal level reaches -6dB. Input 3 also has a high-impedance option for DI'ing electric guitars.
The channel 1 to 4 preamps are followed in the signal chain by four rear-panel sockets, which can be switched in pairs for use either as unbalanced line-level inputs, or channel inserts using TRS wiring. Analogue input channels 5 to 8 also have their sockets on the rear panel, but are TRS balanced, while on the front panel each pair features a rotary Sensitivity control and red/green LED signal/peak indicator. Above the input channel 5 to 8 controls is a set of 10 output indicators. These illuminate green when a signal is being output from the relevant channel (handy when investigating routing problems). The remaining channels 9 and 10 are for stereo digital I/O, and are available in both optical and co-axial formats on the rear panel.
The remainder of the front panel is black and slightly recessed, and devoted to output and system controls. First is an illuminated ADAT mode button that when depressed switches the optical digital output socket to eight-channel ADAT format. Alongside this is an External clock button for when you want to sync the UA1000 to other digital gear — its state is remembered even after a power down. You can either use the optical or co-axial S/PDIF input to derive this external clock, or the BNC word clock input socket on the rear panel. Pressing both ADAT and Ext Clk buttons simultaneously switches the optical S/PDIF input to eight-channel ADAT input mode, and all four signal/peak indicators permanently illuminate yellow to show that input signals are now being received from the optical input.
The sample rate is set by a rotary switch that offers 44.1, 48, 88.2 and 96 kHz and User Set options. Only the first two are supported in ADAT mode, while the last comes into play when running the UA1000 Control Panel utility (more on this later). If you change sample rate using the front-panel control you do have to switch the UA1000 off and then on again. The 'zero latency' Direct Monitoring section offers a stereo/mono switch (useful if recording multiple mono signals like vocals and guitars), a Soft Ctrl switch if you want to control monitor levels, pan, and on/off settings using the Control Panel utility, and an overall monitor Volume control.
The rightmost front-panel area houses an overall Output level control with an associated button; when set to the illuminated All position the level control sets the levels of all analogue outputs, while in the alternative Main position it adjusts only the main output signal emerging from outputs 1/2. A five-segment output level LED array shows the post-Output level control signal levels, and a headphone socket lets you monitor this signal. The front panel is completed by a mains on/off switch and a bright blue power indicator.
The rear panel consists of the eight analogue inputs already mentioned, along with the associated input/insert switches for channel pairs 1/2 and 3/4, plus eight TRS-wired analogue outputs for balanced or unbalanced operation, Toslink optical sockets for S/PDIF or ADAT in and out, phonos for coaxial S/PDIF in and out, BNC for word clock in and out, and 5-pin DIN for MIDI In and Out, plus the USB socket for connection to your PC, and a mains power socket. Rubber feet are attached to the case for desktop use, while a pair of bolt-on rack ears is also supplied.
A handy block diagram showing how the host of inputs and outputs, along with their various options, are interconnected appears on the top plate of the UA1000 and in the back of the Owner's Manual. In passing, I also have to say that this 54-page document is the best I've read to date from the Roland/Edirol stable, with nearly everything presented in a logical order, and plenty of examples, screen shots and diagrams included.
As stated in the introduction, the UA1000 is the world's first USB 2.0 audio interface, but with companies like MOTU and M‑Audio already offering Firewire-based products, which one should you go for? For some people the issue will be decided quite simply by whether they have Firewire or USB 2.0 ports on their PC. Many modern PC laptops have both, but although many modern desktop motherboards now feature four or more USB 2.0 ports, far fewer have Firewire support. PCI Firewire adaptors are, however, readily available for desktop machines.
Both technologies offer the ability to hot-swap peripherals, similar maximum cable lengths of around 5 metres, and support for dozens of devices (up to 127 for USB 2.0, and 63 for Firewire). Firewire ports offer more juice to self-power connected devices (1.25A at 12 Volts compared with 500mA at 5 Volts), but many audio peripherals are mains-powered to more easily provide 48 Volt phantom power and higher-spec mic preamps, so this is often irrelevant in practice.
Both also offer comparable speeds — up to 480Mbps for USB 2.0, and 400Mbps for Firewire — although Apple have now introduced Firewire 800 on their 17-inch Powerbook G4 and Power Mac G5 models to cloud this issue. Firewire 800 also supports up to 100-metre cable lengths when using professional-grade optical cables.
USB 2.0 is backwards compatible with USB 1.1, which means that you can still plug slow devices like keyboards and mice into the same ports. You can also plug a USB 2.0 peripheral into an old-style USB 1.1 port in an emergency, but with a bandwidth that's 40 times slower, it will struggle to perform properly.
In tests I've seen with EIDE external hard drives transferring data direct, via USB 2.0 and via Firewire, the direct connection always wins by a considerable margin, as you might expect, but Firewire 400 often achieves double the transfer rate of USB 2.0. This may be important to you if buying external hard drives, but then most musicians still use fast 7200rpm EIDE internal hard drives, and when it comes to an audio peripheral the maximum number of simultaneous ins and outs (and therefore maximum bandwidth) is already determined by its design. Only if you envisage running multiple audio peripherals will you even need to think about which port provides the 'best' performance, and even here the audio peripheral manufacturer should be able to tell you how many units you can run in parallel. The UA1000 drivers already support at least two units using the Device number selection, and perhaps more.
Since USB 2.0 is such a new format, driver support is only provided for Windows XP, and even then you not only need Microsoft's Service Pack 1 installed, but an additional KB822603 update module to cure excessive CPU load during USB 2.0 audio recording and playback. Both of these are supplied on an accompanying CD-ROM, and you can find out more about this Hot Fix in Microsoft's Knowledge Base article number q822603, to be found at http://search.support.microsoft.com/kb/. Perhaps because of this XP-only support, I found the UA1000 drivers far easier to install than those of the UA20 I reviewed in SOS February 2003, with no confusing decisions required, and a handy step-by-step checklist displayed on screen. The drivers support WDM, ASIO 2.0 and MME formats, but not GSIF.
Once back on the desktop I found a new applet in Control Panel that launched the UA1000 Control Panel utility. This incorporates Patchbay and Monitor sections in its main display area, and various other items accessed from the menus above it. The Wave In Patchbay at top left lets you decide which signals are sent to the 10 UA1000 Wave Inputs inside your PC: for each input pair you can choose from any of the Wave Out playback channels, any of the signals currently appearing at the hardware inputs, or the combined output of the Monitor mixer. The default settings are Input 1/2 connected to Wave In 1/2, Input 3/4 to Wave In 3/4, and so on, for recording purposes.
The Output Patchbay controls what signals are sent to the 10 hardware output sockets, but this time it has two possible sets of options, depending on whether or not any Direct Monitor inputs have been enabled in the Monitor mixer. Each provides exactly the same selection of options as the Wave In patchbay, except that the default connections for the 'Direct Monitor: On' set is Wave Out 1/1 connected to Output 1/2, and so on, while for the 'Direct Monitor: All Off' selections you get an extra default 'Same as Monitor On' setting. All will hopefully become clear in a moment.
The bottom half of the Control Panel is devoted to the Monitor mixer, and this is the only area in which the Owner's Manual let me down, providing few details of its various functions, although it didn't take me too long to work them out. The final mixed output signal appears at the Monitor Out via a pair of level sliders and a switch to link them for stereo operation. The various playback channels can be mixed together into this monitor output mix using the 10 Wave Out channels: each has On/Off and Solo switches, a rotary Pan control and a slider control for Level, while each pair has a Link switch to gang the controls together.
If the UA1000's front-panel Soft Ctrl switch is illuminated, the 10 Input Direct Monitor mixer channels provide identical functions to those of the Wave Outs, but if not, their controls are all disabled and the default internal routing of the UA1000 is used instead for direct monitoring. Moreover, with Soft Ctrl enabled, if none of these Input channels is enabled in the monitor mixer, the second set of Output patchbay options labelled 'Direct Monitor: All Off' is used.
This took me some time to get my head around, but it's well worth doing so, since you can set up completely different routings for monitoring and mastering, and then switch between them using the Soft Ctrl switch, while in Soft Ctrl mode you can also quickly activate individual input channels to monitor them while setting up, and disable them to return to a completely different preset monitoring setup. This is a system that will benefit from some thought before you find the best approach for your own music making, but it's certainly versatile.
I did find it a little difficult to set accurate slider positions using the mouse, but a right-click launches a menu with a selection of useful values (0dB, +6dB, -6dB, and so on) for individual channels as well as for global slider settings, while numerous keyboard shortcuts are available to select and alter the various panel controls in both coarse and fine increments. Other menu options include the ability to change the state of various front-panel switches such as the modes of the clock, digital output, direct monitor and output volume (their current status appears across the bottom strip of the Control Panel), and presets for the Wave In and Output patchbays and Monitor mixer.
Five Control Panel memories are available for storing and loading the various front-panel modes and control-panel settings, which can be handy if you're in the habit of regularly changing your gear connections. There's also a sixth User Set, and this is the reason for the final User Set position on the front-panel Sample Rate control — when set to this position, the UA1000 reloads these values from its internal memory when you power up. You can also store the User Set with a sample rate of 192kHz: in this mode there's no patchbay, monitor, or recording capability, but once you reboot the UA1000 you do achieve 192kHz playback from outputs 1/2 and headphones, which should allow uncompromised DVD-Audio playback.
The Control Panel can also launch a separate window where you can choose from various audio buffer sizes and enable/disable the UA1000's ASIO Direct Monitor facility. Sadly Edirol don't seem to like displaying the current buffer size, but you can discover this from within music applications that do provide a readout, such as NI's Pro 53. Despite the warning that you have to quit the music application and relaunch it after changing buffer size, I didn't find this to be the case, at least in Cubase.
- A-D converters: 24-bit, 64x oversampling (part of AK4528 Codec chip).
- D-A converters: 24-bit, 128x oversampling (part of AK4528 Codec chip).
- Sample rates: 44.1, 48, 88.2 and 96 kHz (plus 192kHz playback only to output channels 1/2 & headphone).
- Inputs 1 to 4: balanced or unbalanced XLR or TRS quarter-inch jack, nominal input level -60 to -16 dBu (pad off), -40 to +4 dBu (pad on), rear unbalanced input/insert +4dBu, switchable +48V phantom power per pair, high-impedance 470kΩ guitar option on input 3.
- Inputs 5 to 8: balanced or unbalanced TRS quarter-inch jack, -20 to +4 dBu nominal input level.
- Analogue outputs: eight balanced or unbalanced TRS quarter-inch jacks at +4dBu (balanced) level, headphone.
- Digital I/O: S/PDIF in and out on phono co-axial and Toslink optical (switchable to ADAT in and out), plus word clock in and out, MIDI In and Out.
- Frequency response: 20Hz to 40kHz +0/-2dB at 96kHz sample rate.
- Residual noise level: -89dBu.
Rightmark's Audio Analyser 5.1 proved that there were no flies on the UA1000 in terms of sound quality. Its frequency response was down by only 1dB when it ran off the bottom of the scale at 4Hz, and met its published spec of -2dB at 40kHz with a 96kHz sample rate. Background noise levels were very low, at -107dBA, when running in 24-bit mode at both 44.1kHz and 96kHz, and all other aspects of the measured sound were excellent, with very low levels of distortion and crosstalk.
Auditioning at various sample rates confirmed the UA1000's high audio quality, and although it uses exactly the same AK4528 converters as my Echo Mia, its clock jitter was significantly better: sync'ing the latter via a co-axial digital cable running the UA1000 S/PDIF Out to the Mia's Digital In and switching the Mia to External Clock noticeably tightened up the stereo image, providing more depth and focus.
The ASIO drivers worked very well with Cubase SX 1.06, running the 'FiveTowers' 2.0 CPU torture test with 6.5ms latency at 44.1kHz, and the lowest 3.3ms setting with the less demanding 'Heaven And Hell' demo, while NI's Pro 53 managed the lowest 10ms Play Ahead setting with the MME drivers. I did try running a low-speed USB 1.1 mouse simultaneously on the same USB 2.0 controller to see if it affected the UA1000's performance, and it seemed to make absolutely no difference, although in general it makes sense to run low-speed USB devices on another controller port pair to avoid possible conflicts.
If you want an analogue eight-in/eight-out rackmounting box with digital I/O, there are quite a few contenders, including Echo's Layla and M‑Audio's Delta 1010 in the PCI category, and MOTU's Firewire-based 828 MkII. However, if you want a more versatile selection of mic and guitar as well as line-level inputs, the field narrows considerably. Aardvark's Q10 is a worthy contender with eight mic/line inputs, two of which have the option of high impedance for guitar use, but there's no ADAT option and slightly higher background noise levels. ST Audio's DSP3000 (review coming soon) is slightly cheaper at £689, and again has eight mic inputs compared with the UA1000's four, but lacks the high-impedance guitar input and has slightly worse audio performance. Edirol's own DA2496 offers two mic/line, two guitar/line, and a further four line-level inputs plus S/PDIF digital at a rather cheaper £499, but its audio performance is also rather more modest and again there's no ADAT support.
However, if you don't want a PCI-based solution, there's very little to directly compete with the UA1000. Firewire audio peripherals may have been around for longer, and if in a year's time Yamaha's mLAN really takes off then it might make more sense to take the Firewire route. However, you should always buy based on what's available now, and I found the UA1000 experience a wholly pleasurable one, due to its easy installation, versatile options, excellent audio performance, and absolutely no problems during the review period. As far as I'm concerned, USB 2.0 is here to stay.