Review: TL Audio M1 Tubetracker
Extra warmth is certainly something the planet could do without right now, but audio remains the exception.
11 February 2007
Review: Stephen Bennett
When I was a teenager I was especially fond of old Science Fiction novels from the ’50s. In these books, square-jawed adventurers would ply the space lanes of the 21st century in rockets that were, more often than not, packed full of valve-based scientific equipment. As it turns out, the authors’ prediction that valves would still be in use in the following century was in some small way correct… unfortunately, predictions that beautiful Martian Amazon women might abduct Earthmen to re-populate their planet have proven slightly less accurate…
HEALTHY VALVES FOR A HEALTHY SOUND
In the audio sector, valve technology is alive and well and steadily appearing in more and more equipment. Valve-based audio gear is – as we’re all well aware – perceived to add ‘colour’, ‘warmth’ and harmonic distortion to a signal, and since the advent of digital recording (some time ago now), an increasing number of companies have entered (or re-entered) the thermionic arena. TL Audio is, of course, one such company that has been producing valve-based, stand-alone compressors and preamplifiers at various price points for many years. The recently released M1 Tubetracker is TL Audio’s latest offering, packaging its now considerable expertise in this area into a traditional console format that’s aimed squarely at the professional and serious project studio user.
Physically, the Tubetracker is a compact tabletop unit with a nice retro-look… and it’s very heavy too, which is what you might expect as it’s full of valves! There’s a chunky external power supply unit that feeds the Tubetracker from a special multi-pin plug, and the valve circuitry is a high-voltage design, which produces quite a different sound to the low-voltages used in many budget units.
The oiled-oak wooden end cheeks and armrest look very nice but feel a bit soft and I suspect could get a bit marked over time. It may seem like a strange thing to say in a review of a piece of audio equipment but the Tubetracker smells lovely; the mixture of wood and hot tubes is delightful and I was instantly transported back to my teenage years and the happy times I spent tinkering with old valve radios!
THE LAYOUT
The rear of the Tubetracker is blank, apart from two removable panels. One takes a card, which provides a stereo digital output, the other an Adat interface, which allows you to record all eight of the desk’s channels direct to your digital audio workstation at up to 24-bit/96k. The layout of the Tubetracker is very straightforward. Each channel sports non-motorised 100mm faders that have a very light feel with plenty of resolution at the lower end of their travel. Sitting above these is an area where you can write track information with a chinagraph pencil – although I’d have preferred a proper scribble strip along the bottom of the desk. Next comes a ‘Drive’ LED, which gives you an indication of how hard the valves are being worked when you increase the input gain. This is, of course, what the Tubetracker is really all about – adding that ‘valve sound’ to the recording chain. The valves are incorporated into the Microphone and Line preamplifier channels and the rest of the recording chain is based on low-noise solid-state circuitry. A peak LED along with Mute and PFL (Pre-Fade Listen) buttons come next, followed by the (–3dB gain law-abiding) pan knob. Each channel has two aux sends, one of which has a PFL button. The desk has simple three-band EQ with fixed-frequency high and low controls and a sweepable midrange. There’s also a separate defeat button to allow you to rapidly audition and/or bypass the effect of the EQ on the audio. An input gain control comes next, along with the microphone and line input sockets and buttons for 48V phantom power, phase reverse, high-pass filter and a 30dB pad. Unlike most of the other buttons on the desk these have no associated LEDs, but it’s still quite easy to ascertain their ‘in’ and ‘out’ status. All pretty standard fare then, and all extremely useful in the studio or at a gig – especially as all the Tubetracker’s inputs and outputs are on the top rear panel for easy access.
NEED TO KNOW
The Tubetracker’s master/monitor section – ‘basic but funtional’.
CONNECTIVITY
Speaking of inputs and outputs, the Tubetracker’s are all balanced 1/4-inch jacks apart from the XLR plugs and sockets used for the microphone inputs and main analogue stereo outputs. Each channel has a direct output that lies after the valve stage, EQ, and insert, but before the fader for direct connection to a multitrack recorder, and there’s also insert send and return sockets on each channel.
The monitoring section is basic but functional. There’s a loudspeaker mute button, which affects both the main outputs and the alternative speaker outputs – which are selected by a separate button on the panel. A nice large knob controls the monitor levels and you can route two two-track sources back through the desk. A single headphone socket is controlled by a dedicated knob, although I would have preferred to have seen two independent headphone outputs with their own volume controls, as this would be very useful in a project studio where it’s often just the engineer and a single musician recording in the same room. The Aux 1 returns and Master Aux sends all have their respective level knobs and the Aux 1 return has its own pan and level controls. Unfortunately there’s only one dedicated aux return so the second send has to be routed back through the main mixer channels. Having said that, it’s common to use the second aux send to set up a headphone submix anyhow, so this won’t necessarily be a problem.
The mixer is well equipped with PFL controls, including an overall PFL level knob. The desk also has several small verniers [the small trim controls used to make fine calibration adjustments to a control device – Ed] accessible with a jeweller’s screwdriver through small holes in the front panel, and you can use these to set PFL left and right balance, overall output levels and meter calibration. The desk also has two circular and well-lit VU meters, which are perfect for setting levels – especially as they both have a useful peak LED situated above them.
The desk is a direct 8:2 format so there’s no sub mixing possible. But as it’s really designed for use with a DAW this shouldn’t be too much of a limitation. The build quality of the desk is exemplary. Ergonomically it’s very good, with plenty of space around the controls. The knobs feel chunky with well-defined centre detents and the buttons have enough difference in the ‘in’ and ‘out’ positions for you to be sure of the setting even in low-light situations. The faders feel a little flimsy, however, and the slider knobs came off a couple of times, but I can’t fault their audio performance. The Tubetracker is a semi-modular design with each channel and the monitor sections being held in with a few Phillips screws, so it’s relatively easy to replace defective sections. One nice thing about the Tubetracker, especially if it’s being used in a project studio situation, is that it’s cooled only by convection – there are no fans in the desk or the supplied PSU. This makes it silent in operation and it doesn’t get too warm, provided you leave plenty of room around the desk.
The resulting sound was so good I ended up mastering a whole album using this setup
AND SONICALLY SPEAKING?
The all-important question, of course, is how does it sound. To find out I installed the Tubetracker in my recording studio and used it on a full band session using the post-valve stage direct outputs fed into a ProTools interface and Logic Pro. As we could just re-patch the Tubetracker in place of our usual mid-priced, solid-state mixing desk, it was pretty easy to do some comparative recordings. The desk worked flawlessly and we didn’t have to consult the manual once during the session. Listening back to the recordings, we could easily hear that the tubes had imparted a nice ‘sheen’ and some weight to the audio – even though during the session we’d been careful to keep the Drive LEDs from coming on.
Using the desk to mix a previously recorded song, again it added a pleasing (dare I say it) ‘warmth’ – especially when we upped the input gain enough to get the Drive LEDs flashing. I tried strapping the desk across the stereo outputs of my MOTU 896 and patching a Universal Audio LA-2A levelling amplifier and a Manley Massive Passive EQ into the inserts points to form a makeshift analogue mastering processor. The resulting sound was so good I ended up mastering a whole album using this setup. The EQ on the desk, while basic, is very musical and appears to have pretty good phase coherence – although it would have been nice to have more control of the high and low frequencies.
The microphone preamps are tonally comparable to my old TL Audio PA-1 Dual Pentode stand-alone model – they are just different sounding rather than lacking in any way. When recording vocals (using my Rode NTK valve mic), I actually preferred the sound of the Tubetracker, but with a Neumann U87 there was little apparent difference. So even if you look at the desk from the standpoint of it functioning as a compact eight-channel microphone preamp, the Tubetracker is in some ways quite a bargain.
THE INNER TUBE
The Tubetracker is a basic and functional desk, which (of course) makes it very easy to use. The manual is very well written with lots of practical tips and advice on how to achieve the best results from the valve stage, and the overwhelming sense I got was that the Tubetracker feels more like a cut-down version of an expensive desk rather than a bloated budget model. Although TL Audio suggests the Tubetracker is ideal as a project or home studio desk, it’s a lot more expensive than similarly specified non-valve based offerings from other companies. However, if you need (or you’d like) eight microphone preamps, or feel that your multitrack DAW recordings are sounding rather sterile, the Tubetracker may be an ideal solution – especially as it has the added advantage that it can be used as the basis for a rather nice mastering processor as well.
RESPONSES