Line 6 Toneport UX1 & UX2

Line 6's latest products are USB boxes that turn your computer into a low-latency amp-modelling system.

Line 6's Toneport UX1 and UX2 are computer recording interfaces aimed at the guitarist or bassist who might also want to record vocals and other instruments. In each case, you get a two-in, two-out USB audio interface with mic, line and instrument inputs and a suite of amp and effect modelling software derived from the Pod XT and Bass Pod XT, plus some newly added vocal preamp models. The modelling effects on offer here are not plug-ins, but operate directly on the input source before the host application. The benefit is that you can hear your effected input signal with no perceptible latency when recording, regardless of how large a buffer size you set in the host application.

Both packages come with exactly the same Gearbox software (as well as a cut-down version of Ableton's Live 4 loop-based sequencer) and offer the same sound quality. What's different is that the UX2 has more connectivity options and features a nice pair of frog-eye meters, as well as phantom powering for capacitor microphones. Both use USB connectivity and draw their power from the USB buss so there's no need for an additional PSU. However, as with all USB interfaces, it's best to connect the interface to a dedicated USB port rather than a hub.

UX1 Or UX2?

The cheaper UX1 has stereo line ins and unbalanced line outs on quarter-inch jacks, one XLR balanced mic input and one high-impedance instrument input jack. A single headphone out is also included, but there's no phantom power for the mic input. There are rotary controls for mic gain and output level and there's also a stereo jack monitor input so that you can combine the output of your computer with that of the UX1 if you happen to be running an additional soundcard or interface under those operating systems that allow it. This is important because the included software will only run with the UX1 connected, and the near-zero-latency monitored signal always emerges from the UX1, even if you have routed the rest of your sequencer audio through a different interface. It's important to switch off software monitoring in your audio host software when recording, otherwise you'll hear both the near-zero-latency version of what you're singing or playing plus the DAW version delayed by whatever latency your audio drivers are set to.

The UX1 and (above) the UX2.As an interface, the UX1 normally operates at 24-bit, 44.1kHz or 48kHz. It works fine as the sole interface in a computer setup, providing you only need two inputs and two outputs, and the output level control is ideally placed for setting the level of connected active monitors or headphones. When you install the Gearbox software that comes with the unit, you get drivers supported by ASIO, WDM and Mac OS X Core Audio. There's also a 96kHz mode that uses sample-rate conversion. The Toneport still operates at 44.1k or 48k, but the driver will sample-rate convert up to 96k so you can use the device to work on projects created at 96k. Handling this at driver level gets around the USB bandwidth limitation and allows simultaneous I/O while recording at 96k.

The slightly more expensive UX2 provides two front-panel instrument jacks (one normal, one padded down for high-output guitars) as well as two balanced XLR mic inputs with globally switchable 48 Volt phantom power. Note that only one instrument input channel is available, but if you were to use a DI box into the other's channel's mic input or line input, I see no reason not to use two sets of guitar amp models at the same time, or one guitar and one bass.

There are twin level meters, though most people will probably use the meters in their DAW software to confirm the recording levels, and on the UX2 there are separate level controls for the phones and main stereo output. On the rear panel you get the same connections as on the smaller UX1, augmented by a coaxial S/PDIF output and a pair of footswitch jacks, which can be assigned to MIDI commands for stopping and starting recording, bypassing effects and so on.

A signal-to-noise ratio in excess of 100dB is quoted for both models, and having used them, I've found no reason to dispute this figure; they're very clean and quiet.

The Gearbox software in action. The row of icons along the middle shows the signal path from left to right, with the selected amp model displayed above, and the effects displayed below.

What's In The Gearbox?

What makes the Toneports very different from conventional USB audio interfaces is the included Gearbox software. The easiest way to describe the operation of Gearbox is that the software amp models, which run on your computer, behave more as though they reside in the interface itself. By this I mean that when you come to select the Line 6 interface as an input source in your DAW software, the signal that arrives is already processed via the Gearbox amp modelling section which opens as a separate program in a separate window from your DAW. You don't have to mess around with Rewire or anything like that — what you hear is what you record. Or very nearly.

In fact, the designers at Line 6 have given the units four 'to-DAW' outputs to recording software, two of which come from the end of the signal chain and two of which come before the last few post-output 3/4 effects. You always monitor the full effects chain, but can decide to take your record feed from before the post- effects, enabling guitar, bass or vocals to be recorded without delay or reverb but to still have those effects available for monitoring. This is a wonderfully uncomplicated way of setting up monitoring reverb for vocalists, but the down side is that you can't use these effects when you come to mix (unless you route audio back through the box) as they are not available as plug-ins. This ability to tap into the signal path before the post- effects is also lost when you record both channels at once, as both to-DAW outputs are then needed to route the two channels. In dual-channel mode, you can use two sets of amp or preamp models at the same time, one to process each of the two inputs. In practical terms, this means you can use a chain of vocal preamps and effects as well as guitar modelling when recording guitar and vocals or guitar and bass at the same time, keeping both signal paths completely discrete.

Near Zero-latency Monitoring

I tested the software in Logic Pro and deliberately set the largest possible buffer size to give me noticeable latency. As promised, the guitar I was playing appeared at the UX2's output with no noticeable latency at all — it felt just as immediate as playing through a hardware Pod XT. For the next test, I set up an Aggregate Driver under Mac OS 10.4 so that I could use my MOTU 828 Mk2 and the UX2 at the same time. This placed the four possible UX2 to-DAW outputs (1/2 and 3/4) at the end of my list of available input sources, and I chose the MOTU as the default output of my system. This worked absolutely fine, and though using an Aggregate Driver always seems to make the latency noticeably worse in the host DAW software, I could still the guitar I was recording with no noticeable delay.

However, it should be pointed out that you can only hear the input with near-zero latency if you monitor via the line outs (or the S/PDIF socket) on the back of the interface — there is, of course, no way to pipe it via your other audio interface without incurring the latency imposed by its buffer settings. This means in practice that if you use the Toneport with another interface, you need to monitor the audio from both interfaces at once when overdubbing to retain the benefits of near-zero-latency monitoring.

Models In Action

The models included are based on the Pod XT algorithms, and though you get slightly fewer of them than in the hardware equivalent, the quality is exactly the same. There are 16 guitar amp models, five bass amp models and six vocal preamps. On top of this there are 24 effect modules that can all be used on guitar, bass or vocals, and if these aren't enough, you can download optional Line 6 Model Packs from Line 6's web site to upgrade your software to include all the Pod XT models or go further and buy the additional Vetta amp and effect models currently available to Pod XT owners.

New to the Toneport are models of classic mic preamps and studio effects. The amplifiers that you do get cover a broad tonal spectrum and include models 'inspired' by various Marshall and Fender classics as well as Vox, Soldano and Mesa Boogie. As with the Pod XT, you can switch speaker cabinets around to get more tonal permutations and there are some superb effects, including a very realistic tape-loop echo complete with wow, flutter and just the right degree of degeneration as the sound repeats.

At the very start of the effects chain is a conventional noise gate, but there's also a new hum reducer that works by first 'learning' the hum from your guitar and then reducing it. The manual doesn't say whether this is achieved by adding it back to the guitar signal out of phase, by automatically configuring a series of notch filters or by subtracting a noise fingerprint, but it works. There's a significant reduction in hum with no apparent effect on the guitar tone, so this is actually more sophisticated than what goes on in the Pod XT hardware. Following the noise gate is a volume pedal, which can be controlled remotely via MIDI, as can the wah pedal that comes next. A pre/post switch allows the volume pedal to be moved to the end of the effect chain, immediately prior to the Send 3/4 output. Then we have the stomp effects, which can be one of several distortion types, a Vetta compressor or a choice of male or female de-esser. In all cases, the number of knobs you get to adjust is similar to what you'd expect on a stomp pedal — there's nothing too scary. If you switch the pre/post order of any effect, the current signal path is shown with each of the icons in its correct position in the chain.

From there, the signal feeds into the amp model section, where you get to choose the amplifier type, the speaker cabinet, the type of mic and its position. All the usual amp controls (Drive, EQ and Volume) are present, though the EQ configuration changes to suit the amp type being modelled. Extra EQ controls not present on the original amp appear in a small window to the right of the main controls to give the user a little more tonal flexibility.

Clicking on any stomp pedal icon bypasses it and selects its edit window. A graphical panel display is shown in the lower half of the window and the amp or preamp controls in the upper half; clicking on the amp icon shows the miking arrangement for the current speaker cabinet. The only thing I found confusing was that on the vintage preamp model, it was difficult to tell which of the four protruberances on the control knobs was actually the pointer!

Gearbox's guitar tuner.Directly after the amplifier comes another compressor block with just threshold and gain controls, then a four-band EQ with variable-frequency shelving filters at each end and swept filters for each of the middle two bands. Following the point in the chain where send 3/4 can be tapped off come the Mod Reverb and Delay blocks, though all three have pre/post switches that allow them to be moved before the send 3/4 tap point when required. Output 1/2 always comes from the end of the signal chain. This flexibility makes it possible to monitor without recording effects such as delay or reverb that help your playing but which you'd like to replace later in the recording process.

At the top of the window, just to the right of the patch name window, are three buttons. The first changes between the stored setting and any edits you have made, allowing you to make comparisons before saving. The second bypasses the modelling chain, giving you a clean signal path and shedding any computer CPU load that Gearbox imposes, while the third opens up a very precise and stable guitar tuner with an analogue meter-style readout.

Where two-channel operation has been selected in the input source menu, you can set up two independent processing chains for the two input channels using the two icons immediately to the left of the patch name to switch between their controls. In this mode you lose the ability to record a different signal path from the one you monitor, as one channel comes out via outputs 1/2 and the other via 3/4. The reason two channels are required for each output is that some of the effects are stereo.

Other controls allow the level of the output to be adjusted or muted and there's also an output pan control with a mono button for when you want to record the output as a simple mono track. Separate Record and monitor Level controls are available to help you set the correct balance of track and the source being recorded. Overall, the graphical aspect of Gearbox is very well thought-out and almost everything about it is intuitive. Patches, or Tones as they are called in the documentation, can be saved independently for the two channels and there's a generous selection of factory patches to get you started.

The slightly more expensive UX2 has additional features including a second mic preamp, phantom power, footswitch sockets and an S/PDIF output.