M-AUDIO MicroTrack 24/96

Sep 1, 2006 12:00 PM, By Rudy Trubitt with Bruce Koball

What's your vision of the perfect pocket-size audio recorder? Here's mine: It would be tiny and use solid-state media (a memory card) rather than rotating storage (a hard drive). It should accept ⅛-inch minijack mics as well as professional phantom-powered mics. It should record mono or stereo at a wide range of resolutions, from on-the-fly MP3 encoding up to high-sampling-rate, 24-bit linear PCM files. After recording, I should be able to mount the recorder or its media on my computer desktop so that I can simply drag the files into my audio editor. Oh, and I'd want it to cost less than $500.

Back in the previous century, this would have been a pipe dream. But thanks in part to increasing integrated-circuit functionality fueled by portable consumer audio devices like the Apple iPod, M-Audio has delivered the MicroTrack 24/96, a tiny high-resolution audio recorder that has all the features on my wish list — including the low price.

We tested a pair of MicroTrack 24/96s for this review: one provided by M-Audio, the other purchased through regular retail channels. We ran multiple firmware revisions (including 1.1.5, 1.2.3, 1.3.3, and 1.4.0) and made hundreds of recordings over a seven-month period. Although we got off to a rocky start with the MicroTrack due to buggy firmware, with the latest firmware rev, it has turned out to be a capable performer.

Ins and Outs

A bit larger than a deck of cards (see Fig. 1), the MicroTrack boots up in roughly 30 seconds. Its front panel includes the power button, an LCD screen, a record button, left and right record-level controls, and a headphone volume control. The all-important record button is easy to find regardless of whether you are operating the device while looking at it or just by feel alone.

When the recorder is held in your right hand, your thumb comes to rest on the Nav button, a lever that can be pushed up or down as well as clicked inward. The Nav button serves as a menu scroller, an Enter key, and a play, pause, fast-forward, rewind, and skip-to-next/last file control.

On the left edge of the unit, your index finger aligns with a menu button that toggles between system options and the main record screen. Other left-edge controls include a 3-position input-level switch (L, M, and H for low, medium, and high levels of gain, respectively), a phantom-power switch, and a Hold switch, which disables the other controls to prevent the effects of accidental button presses when the unit is in your pocket.

The top panel sports two stereo minijacks (mic input and headphone output) and two balanced ¼-inch TRS jacks for mic-level or -10 dB line-level signals (see Fig. 2a). The MicroTrack gives you 30V of phantom power for the ¼-inch inputs rather than the typical 48V. Some professional condenser mics won't run properly at 30V, so check the specs for your mic's power requirements before using it with this recorder. The bottom panel has a pair of RCA line outputs (which are affected by the headphone volume control), a coaxial S/PDIF digital input, and a mini USB connector (see Fig. 2b).

A T-shaped stereo electret condenser mic is included with the MicroTrack, and I was surprised at how much I ended up using it. The mic doesn't provide much in the way of stereo imaging, but it is small and convenient: I've recorded lots of usable audio with the MicroTrack peeking out of my shirt pocket. The unit also comes with an AC charger, a mini USB cable, a soft case, and stereo earbuds.

An internal lithium ion battery provides power. Although we were able to get four hours of record time using the included mic, you can expect less when using phantom power. The battery recharges when the MicroTrack is connected to a computer via USB or when you use the AC charger. M-Audio estimates that the battery will last 500 discharge/recharge cycles, after which the factory will replace it for $75. M-Audio offers no external battery, but my colleague Bruce Koball designed and built a portable adapter that supplies regulated 5V through a USB connector from an external battery.

Check Your Levels

My first test was to make rehearsal tapes of the band I'm in, the Sippy Cups. I set the recorder, with T mic attached, on top of my bass amp, near the drum kit. The results were quite usable, but I found that even with the record level and input trim controls set to minimum, I was still seeing the occasional digital overload. To alleviate this problem, M-Audio offers an optional stereo mini in-line attenuator ($19.95) that will add 10 dB of headroom to the MicroTrack's minijack input.

I also found it a bit awkward to control the MicroTrack's input levels. The record-level controls provide only a 12 dB range; I wish it were at least twice that. M-Audio notes that this control is actually a gain trim for the mic preamps, not a fader. Nevertheless, when I see a record-level button, my expectation is that turning it down all the way will silence the input. That is not the case with the MicroTrack.

When using the ⅛-inch input, only two of the three sensitivity settings are active; they provide an additional 12 dB of sensitivity adjustment. So, the 12 dB from the level control and 12 dB from the switch gives you a total range of 24 dB on the minijack — not a lot of room to maneuver.

The ¼-inch TRS inputs have a wider range. First, you get 12 dB from the front-panel fader. In addition, all three positions of the L-M-H switch are active, and together they provide approximately 18 dB of level adjustment. Add to that a menu-selected 27 dB of boost, and you end up with a total adjustment range of nearly 57 dB when using the ¼-inch inputs.

When miking quiet sounds, be sure to engage the 27 dB boost. The MicroTrack's manual incorrectly describes it as “digital gain,” but it's part of the analog signal path. We measured a 15 dB improvement in the MicroTrack's signal-to-noise ratio when using it.