Apogee has released a pair of high-quality portable digital interfaces that together form a complete high-end I/O setup that's great for recording and playback on the go. The Mini-Me is a stereo mic/line/instrument preamp with a 24-bit, 96 kHz A/D converter. The Mini-DAC is a 24-bit, 192 kHz D/A converter.
Both devices offer USB connectivity. However, the Mini-DAC was designed to interface conveniently with the Mini-Me, so it takes just one USB connection to record to your computer through your Mini-Me while simultaneously monitoring with the Mini-DAC.
FROM A TO D
As an A/D converter, the Mini-Me offers 44.1, 48, 88.2, and 96 kHz sampling rates and supports 16-, 20-, and 24-bit word lengths. All three word lengths are available at 44.1 and 48 kHz, but the 88.1 and 96 kHz sampling rates operate at 24 bits only. Apogee's UV22HR dithering algorithm is automatically applied during 16- and 20-bit operation.
The Mini-Me is made of sturdy, lightweight aluminum, with the controls laid out somewhat snugly on the front panel (see Fig. 1). All connections are on the rear. When the left and right input-level controls are set fully counterclockwise, the XLR inputs on the back operate at line level instead of mic level. A pair of small, recessed screws on the front panel, which require a jeweler's screwdriver to access, are used to calibrate the incoming line level. I found this arrangement inconvenient for field recording: I'd prefer a simple mic/line input switch instead, allowing the knobs to control the level of either. When a ¼-inch instrument input is connected, the knobs automatically function as instrument-level controls. Two four-LED ladder-style input meters reside between the level controls The Mini-Me's front-panel power switch doubles as a +48V phantom-power selector. Holding the switch to the far right for a couple of seconds activates or defeats phantom power. The 12-position Sample Rate knob selects between the various combinations of sampling rates and bit depths. The Mix control sets the balance between the direct signal and the signal at the USB input. The Mix control doubles as a push button that switches between mono and stereo operation when one mic input is used. The front panel also includes a headphone level control, a switch to select dynamics processing (off, limiting only, or compression and limiting), and a switch to select one of three compression curves.
On the rear panel, the Mini-Me has a pair of Neutrik combo jacks. Mic and line signals are received through the XLR jacks, and the ¼-inch jack is for high-impedance signals only. The rear panel also has an ⅛-inch stereo headphone jack, a USB port, S/PDIF and AES/EBU digital outputs, and a power jack for the external power supply or an optional battery. For field recording, a lead-acid battery (available from Eco-Charge, Inc.) is the only way to go.
As a bonus, the Mini-Me can output digital black from the AES/EBU and S/PDIF ports at all four sampling rates when the unit is not sending digital audio information. This allows the Mini-Me to be a high-quality, low-jitter master clock-source for a digital studio. However, the unit does not have a standard BNC-style connector for dedicated word-clock output.
The Mini-Me features defeatable limiting and compression circuits to eliminate unwanted digital overs. Apogee's Soft Limit limiter begins rounding peaks at about -4 dBFs, which results in fairly transparent limiting that leaves most of your recording untouched. The Push-It compressor circuit is designed for more aggressive gain control, audibly squashing the sound and allowing an overall hotter signal to be digitized. The unit offers three preselected gain-reduction curves, but no adjustable compression parameters.
I liked the Soft Limit feature quite a bit because it let me record sharp, transient sounds — such as metal clanks — without worrying too much about overloading the circuit. It worked well on a number of sources for which the maximum dynamic level couldn't be predicted, such as concerts and loud sound effects.
I didn't care much for the Push-it compressor, however. Whether recording vocals, piano, percussion, or airplanes, the Mini-Me's compression algorithms added a hard, flat sound that didn't complement or enhance the recordings. My tendency was to stick with the Soft Limit feature, record at a slightly lower level, and then apply plug-in or outboard compression later if needed.
The Mini-Me can act as a front end to any digital recording device through its AES/EBU and S/PDIF ports, but it also includes a USB port for connecting directly to any USB-equipped computer. Apogee has developed ASIO drivers for Windows 98SE, ME, 2000, and XP and for Mac OS 9 and OS X. The CoreAudio drivers in OS X support the Mini-Me as well. As a result, the Mini-Me works with most current DAW applications running on a laptop or desktop machine. The bandwidth of the USB protocol limits the maximum audio resolution to 24-bit, 48 kHz. However, the Mini-Me's AES/EBU and S/PDIF outputs continue to send audio at sampling rates of up to 96 kHz while you're using the USB port.
Under OS X, the CoreAudio driver recognized the Mini-Me as soon as I connected it to my computer. Configuring it as the input and output source under system preferences was effortless, and within a minute of plugging it in for the first time, I was recording audio into the shareware audio editor, Amadeus II. The audio played back flawlessly over USB, allowing me to mix the computer's signal in my headphones with audio coming in through Mini-Me's line inputs using the direct/USB Mix knob.
I used Emagic Logic Platinum 6 on a G3 iBook to test the Mini-Me in a multitrack environment. I recorded a metronome pulse, then recorded clapping against the pulse. USB latency was in the range of 40 to 60 ms, which is about what I have noticed with other USB interfaces plugged into that computer.
To record a series of WWII aircraft for a video game project, I toted the Mini-Me, a Crown SASS-P stereo mic, and a Tascam DA-P1 DAT recorder to the Planes of Fame Air Museum in Chino, California. I ran the mics directly into the Mini-Me, sending a 16-bit, 44.1 kHz signal from its S/PDIF output to the DA-P1.
The Mini-Me's mic preamps and A/D converter were a marked improvement over the DA-P1's internal electronics. The recordings of the planes' massive 60-year-old engines had a nice combination of throatiness and detail. Quiet Foley sounds, such as cockpit levers and switches, came out clean and noise-free.
In the studio, I recorded acoustic guitar, vocals, piano, and jingling keys (my favorite high-frequency test) at several sampling rates. The results were consistently musical, clean, and detailed. The Mini-Me's conversion handled the metallic high-frequency material without creating noticeable distortion or harshness.
FROM D TO A
The Mini-DAC is meant to be used at the end of the digital audio signal chain, typically feeding a pair of powered monitors. It handles a variety of inputs, including AES/EBU; coaxial S/PDIF; optical S/PDIF, ADAT, and S/MUX; and, with the optional input card, USB. All of the standard sampling rates from 44.1 to 192 kHz are supported.
The Mini-DAC has only three controls: a power switch, a level knob, and the Input Select knob (see Fig. 2). The 12-position input selector allows you the flexibility to monitor any of the four pairs of ADAT inputs (channels 1-2, 3-4, 5-6, or 7-8) coming in over Lightpipe, as well as either of the two rear-panel AES/EBU inputs at sampling rates of up to 96 kHz. In addition, you can choose to monitor the AES/EBU inputs together in double mode for 176.4 and 192 kHz operation. The front panel also includes a ¼-inch headphone jack, a set of sampling-rate LED indicators, a pair of signal-lock LEDs, and a pair of signal-level LEDs. It would be nice if the Mini-DAC had four signal-level LEDs per channel the way the Mini-Me does.
The rear panel has a power input; a S/PDIF coaxial jack; an optical jack for S/PDIF, ADAT Lightpipe, and S/MUX signals; a spot for the optional USB input; and a DB9 AES/EBU I/O jack. A DB9 cable, with two AES/EBU XLR inputs at the other end, is included. I would prefer to have two AES/EBU XLR inputs on the rear panel, but there's not enough room. The analog outputs are a pair of +4 dBu XLR jacks and an unbalanced -10 dBV ⅛-inch stereo jack.
Whether it's monitored through headphones or through the XLR outputs, the Mini-DAC's sound is clean, detailed, and unhyped, with a smooth frequency representation across the spectrum. I listened to several projects of my own as well as recordings I know very well, such as the Beatles' Sgt. Pepper's Lonely Hearts Club Band and the recent Steely Dan releases, and the Mini-DAC revealed subtle nuances and details I had never heard before. I have no doubt that the Mini-DAC would be a very useful tool for presenting an objective sonic perspective during the mixing process.
A peculiar bug popped up when I used the Mini-DAC's USB connection. When powered up, the Mini-DAC slaved to USB at a sampling rate of 48 kHz, and all of the 48 kHz files sounded terrific when played back — tight, clean, punchy, and loaded with detail. However, the 44.1 kHz files sounded terrible — noisy, grainy, and flat — because the Mini-DAC did not automatically resync to 44.1 kHz, causing improper sampling-rate conversion. Unfortunately, there are no controls in the Mac's system preferences or on the Mini-DAC to set the USB's sampling rate. To resync USB to the proper sampling rate, I had to disconnect the USB cable from the Mini-DAC and reconnect it. When the Mini-DAC received signals from the AES/EBU ports, it resynced correctly to any changes in the sampling rate.
Apogee's Mini-Me and Mini-DAC make a fine pair. Their sonic qualities are first-rate, and their flexibility in accepting and translating a wide variety of digital formats will make them welcome in many professional studios. More importantly, they can run on battery power, and their portability, solid construction, and USB capabilities make them ideal for field and concert recording applications.
If you work only in a stationary recording studio, there are other converter options available that offer more features for less money. But if the notion of a high-quality, lightweight, and mobile recording system is of interest to you, then these babies are definitely worth examining more closely.
mic preamp and ADC
$1,495 ($1,295 without USB)
FEATURES4.0EASE OF USE3.5AUDIO QUALITY4.5VALUE2.5RATING PRODUCTS FROM 1 TO 5
PROS: Great Sound quality. Built-in compressor and limiter. Highly portable. Rugged.
CONS: No word-clock in. Must be the master clock source. Recording through USB limited to 44.1 or 48 kHz. Line-input level can only be adjusted from tiny calibration screws. Compression algorithms are somewhat heavy. No status indicator for mono/stereo headphone switch.
Analog Inputs(2) XLR/¼" TS combo jacksAnalog Outputs(1) ⅛" stereo headphoneDigital Outputs(1) XLR AES/EBU; (1) S/PDIF coaxial; (1) USBSampling Rates44.1, 48, 88.2, 96 kHz (USB max. rate 48 kHz)Mic Amp Gain Range12-65 dBWord Lengths16-, 20-, and 24-bit (24-bit only at 88.2 and 96 kHz)Dynamic Range105 dBATHD+N-94 dBFrequency Response20 Hz-20 kHz (±0.2 dB @ 44.1 kHz Fs)Power Source6-16 VDC (adapter included)Dimensions5.4" (W) × 1.5" (H) × 9.8" (D)Weight2 lb.
Analog Outputs(2) XLR; (1) ⅛" stereo; (1) ¼" stereo headphoneDigital Inputs(1) AES/EBU D-sub; (1) coaxial S/PDIF; (1) optical S/PDIF/ADAT/S/MUX; (1) USB (optional)Sampling Rates44.1, 48, 88.2, 96, 176, 192 kHz (±10%)Word Lengths16- and 24-bitFrequency Response10 Hz-20 kHz (±0.2 dB at 44.1 kHz)THD+N-107 dBDynamic Range119 dBACrosstalk-125 dBPower Source6-16 VDC (adapter included)Dimensions5.4" (W) × 1.5" (H) × 9.8" (D)Weight2 lb.
($995 without USB)
FEATURES4.0EASE OF USE3.5AUDIO QUALITY4.5VALUE2.5RATING PRODUCTS FROM 1 TO 5
PROS: Great sound quality. Highly portable. Rugged.
CONS: Must disconnect and reconnect the USB cable when switching from 44.1 kHz to 48 kHz audio.