FIG. 1: The MicroTrack 24/96 is designed to fit into your pocket or the palm of your hand. The -multifunctional Nav button on the right can be controlled with your thumb when the recorder is in your right hand.
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.
FIGS. 2a and 2b: The top of the -MicroTrack 24/96 (2a) includes two 1/4‑inch line inputs, an 1/8-inch stereo mic input, and a stereo headphone output. The bottom (2b) offers RCA line -outputs, a S/PDIF -digital input, and a mini USB port.
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.
Speaking of which, noise performance of the mic preamp is respectable. We did fairly extensive measurements and found the MicroTrack to be 5 dB quieter than an older Sharp MD702 MiniDisc recorder, 3 dB noisier than a Sony D3 DATMan, and about 8 dB noisier than a Fostex FR-2 (albeit, this recorder costs substantially more than the MicroTrack). We also found the MicroTrack's ¼-inch inputs to be a bit (2 dB) quieter than the ⅛-inch inputs.
The balanced ¼-inch inputs clip when confronted with +4 dBu line levels. Even a -10 dBV signal from a CD recorder or cassette deck can push the MicroTrack into the red. However, if you can keep signal levels within the unit's operating range, you will get fine-sounding tracks. We made some clean live rock-band recordings using a Shure VP88 microphone plugged into the ¼-inch inputs, and we got excellent results recording a loud jazz combo and a choral group in a lively hall using a Røde NT4 (which can run on an internal 9V battery) patched into the minijack mic input.
The MicroTrack's level meters do not indicate a decibel scale, but our tests determined that each of the ten major tick marks represents about 4 dB, with the last tick measuring -39 dBfs. The unit's green signal-present LEDs pop on at -40 dBfs; the red clipping LEDs illuminate at about -1 dB before digital clipping. Unfortunately, the metering feels a little slow when recording and erratic on playback; a sine wave with identical levels in both channels showed the left channel bouncing from 2 to 4 dB higher than the right. In general, my MicroTrack recordings ended up with somewhat low overall levels, due to my uncertainty as to exactly what the metering was trying to tell me.
Happily, the MicroTrack appears to be digitally transparent. Recording from the S/PDIF input, we tested for dropped samples and found none. Next, a sample-for-sample comparison of a 16-bit, 44.1 kHz audio recording revealed no change in sample values. The unfortunate limitation is that you cannot monitor audio while recording from the digital input. This significantly compromises the utility of the recorder as a storage device for an external A/D converter.
In the Field
Cool sounds often happen with little advance notice, and fortunately the MicroTrack is pretty quick on the draw. Once powered up, it takes only a second to start a recording and about five seconds to close the recorded file before you can record new audio.
Each new recording creates a new file. File names are numbered sequentially, starting with file0001.wav (or file0001.mp3). The WAV format limits the maximum size of an audio file to 2 GB. When you reach this limit, the latest MicroTrack firmware is able to switch to a new file automatically, with only a brief interruption in the recording.
My favorite thing about the MicroTrack is that now I can have a decent audio recorder on my person at all times. For example, while running an errand, in the distance I heard a very loud, rapid metallic pounding sound. I had been right in the middle of a sound-design project in which we were simulating the sound of a diesel locomotive engine throwing a rod. Although we were almost done, we were still looking for something more. Three blocks away, I found the source of the sound: a jackhammer so big it was mounted on a mobile crane. The behemoth was busy busting open a huge concrete slab. I whipped out the MicroTrack and captured what turned out to be a key sound element in the final project.
The MicroTrack is equally useful as a musician's notepad. The last three songs I wrote all started out as MicroTrack recordings. Over the course of this review, the recorder served me well as a second deck on assignments for the public radio program Weekend America, and it was used to record numerous production rehearsals and concerts. With the right mic in the right position, the MicroTrack delivered fine recordings.
Up until M-Audio released firmware revision 1.4.0, the MicroTrack had a couple of deadly bugs. One occasionally caused the loss of the current recording; the other prevented new recordings from being made until you reformatted your CompactFlash card. However, these serious bugs appear to have been fixed. If you're using a MicroTrack with an earlier firmware version, we urge you to upgrade. The process is simple, and the upgrade is free.
Other details we hope will be improved in firmware upgrades include a new screen layout so that the record-level graphic indicators do not obscure the peak-level graphics, and a graphics display that is easier to read — a big uppercase RECORD message that can be seen without squinting would be great. Adding the ability to drop markers while recording would make it easy to find specific events in a long recording as well as ease navigation, since the fast-forward and rewind controls are difficult to manage.
In the Pocket
Overall, the MicroTrack 24/96 is a capable semipro recorder. It has become a regular part of my toolkit, accompanying me as a second deck on all of my field-recording gigs this year. Although I wouldn't recommend it as a primary deck for a professional sound recordist, it is an appropriate choice for musicians who want to record rehearsals and song ideas, as well as artists who want to have a digital recorder that they can carry around in their pocket. With the latest firmware installed, the MicroTrack is certainly worth its modest price.
GUIDE TO EM METERS
5 = Amazing; as good as it gets with current technology
4 = Clearly above average; very desirable
3 = Good; meets expectations
2 = Somewhat disappointing but usable
1 = Unacceptably flawed
MICROTRACK 24/96 SPECIFICATIONS
||(1) ⅛" stereo; (2) ¼" TRS
||(2) RCA line; (1) ⅛" stereo headphone
||(1) coaxial S/PDIF input; (1) USB 2.0 port
||MP3: 96, 128, 160, 192, 224, or 320 kbps; WAV: 44.1, 48, 88.2, or 96 kHz
||CompactFlash cards (64 MB-6 GB)
||internal rechargeable: lithium ion
||2.4" (W) × 4.3" (H) × 1.1" (D)
||4.9 oz. (without CompactFlash card)
portable 2-track recorder
|EASE OF USE
RATING PRODUCTS FROM 1 TO 5
PROS: Very portable. Records high-resolution audio. Analog and digital inputs. Attractive price.
CONS: Easy to overload analog inputs. User interface is occasionally awkward.