I do most of my recording outside the comfortable confines of the studio, so it's especially important for me to have gear that not only sounds good, but is easy to use and reliable. Until recently, my primary field rig consisted of a Sony TCD-D8 DAT recorder, a Grace Design Lunatec V2 mic preamp, and either a Shure VP88 stereo mic or a stereo pair of Schoeps mics.
I'm very fond of the now-discontinued V2, so I jumped at the chance to try out its replacement, the Lunatec V3. For an extra $200, the V3 is essentially a V2 with a high-resolution A/D converter (24 bits with a maximum sampling rate of 192 kHz).
PLUG AND GO
The V3 is simple to operate. Plug in your mic (or mics) and an external battery or AC adapter, and connect the appropriate outputs to your recorder. Turn the unit on using the front-panel switch and, if needed, turn on the 48V phantom power too. Press the Fs Select switch for half a second to cycle through the various sampling rates (44.1, 48, 88.2, 96, 176.4 and 192 kHz). Another switch, labeled ANSR, enables dither, which is recommended if your recorder captures only 16 bits.
Point your mics and check the 8-segment LED meters for level. Turn the 5 dB-per-click detented gain controls to get in the ballpark, then fine-tune using the dual trim controls. Rumble a problem? Each channel has a two-position low-cut switch. Engage as needed and off you go.
As easy as using the V3 sounds, I had one major hurdle to overcome when approaching this review: how could I test the unit's high resolution in the field when my portable recorders were only good to 16-bit, 48 kHz? Several midpriced (under $3,000) high-res field recorders had been announced, but none were shipping in time for this review.
There were two reasons I couldn't use a laptop. First, my working style in the field requires walk-about mobility. And then there's digital I/O — or lack thereof. USB isn't fast enough for high-res audio, and my white Apple iBook has no slot for a digital I/O PC Card. (I also worried that delicate proprietary connectors would be involved in such an approach.) I ultimately came up with DIY solution, but before I describe that beast, I'll take a closer look at what the V3 has to offer.
The V3's front panel is cleanly laid out and provides easy access to all controls. I particularly like the stepped gain controls (see Fig. 1). If I have to make a sudden and significant level adjustment while recording, the even 5-step increments can easily be offset during post-production editing. For making small adjustments, the V3's trim knobs allow subtle and precise changes, as they provide only 0 to +10 dB change across their full range of travel.
The rear panel of the V3 (see Fig. 2) is chockful of connectors: a threaded coaxial-barrel DC power input, two XLR mic inputs, two analog XLR outputs, one S/PDIF RCA out, a BNC word-clock output (no word-clock in) and two XLR-3 AES/EBU digital outputs. However, accessing the crowded rear-panel jack field's connectors with your fingers isn't so easy. In cold conditions, my gloves would definitely have to come off if I needed to reseat S/PDIF or DC power cables.
And what's the reason for two AES/EBU outputs? For recording live concerts, the V3's analog, S/PDIF, and two AES digital outputs are all simultaneously active and could conceivably drive four independent recorders at once. But more importantly, the dual AES outputs are used in tandem for the system's highest sampling rates.
Here's the deal: at rates of up to 96 kHz, the single 3-pin XLR digital outputs carry duplicate signals — the left and right channels of the stereo pair. At 176.4 and 192 kHz, the digital audio can be split into two mono signals, with each cable carrying a single channel. This is referred to as “dual-wire” transmission. Most current high-res recorders use this approach for digital I/O. The unit can also operate in single-wire 176.4 and 192 kHz mode. In this mode the AES/EBU outputs transmit stereo data simultaneously. Single-wire and dual-wire modes are selected with an internal jumper. Short cable lengths are recommended for higher rates.
Popping the lid reveals a tidy circuit board stuffed with components. The preamp section is described as “instrumentation grade,” and I'd agree that it's a very accurate and clean-sounding device. The A/D section is mounted on a separate circuit board that can easily be removed by service personnel should a future upgrade become available.
Grace Design's dither system, called ANSR, uses a filtered low-level analog noise source rather than software-generated noise. (Software-generated noise is said to be less random in nature.) You should engage ANSR if you are feeding a device that only captures 16 bits — there's no separate word-depth setting on the V3. I must confess that I have yet to develop a strong preference for either dither algorithm. Because there's no easy way to evaluate ANSR's individual contribution to the overall system, I'll just say that the end result is excellent.
The V3 has a number of circuit-board jumpers, which control a range of options. Digital I/O can be configured for consumer or professional format, and for the previously mentioned single- and dual-wire AES modes. Internal -20 dB pads can be switched with jumpers when recording +4 dBu line-level sources; consumer line levels can be recorded without pads when the mic preamp is set to minimum gain.
Filter slopes (6 or 12 dB per octave) and two cutoff frequencies (in the range of 50 to 125 Hz) can be preset for each channel individually. The V3's front-panel three-way switches let you select a flat setting or either of two low-cut-filter frequencies for the left and right channels independently. I like to use steep slopes and low cutoff frequencies so that if there is too much wind or handling noise I can engage a sharp rumble filter at as low a frequency as possible, leaving the mid-bass region alone. If that doesn't solve the problem, I can flip the filter to the second setting, raising the cutoff frequency for a more extreme low cut.
WALK ON THE MID SIDE
The V3 has a middle-side (M-S) decoder, which is also enabled by internal jumpers. This is a must for me because my primary mics are a pair of Schoeps — usually CMC-6 bodies with CK-5 capsules — that I use in M-S configuration. (For more on M-S recording see “More Than the Sum” in the June 2003 issue of EM; text available at www.emusician.com.) When the decoder is enabled, the left level control sets the overall level of the mono “mid” signal to both channels, while the right varies the width of the stereo image.
Grace did a custom modification for my V2 preamp a few years ago, bringing the M-S decoder to a front-panel on-off switch. The V3 appears to have space for a similar modification, although it's not a standard “price list” item offered by the company. It is, however, extremely convenient if you do M-S recording.
The unit requires either 6 or 12 VDC from a battery pack or AC adapter (neither of which is included with the V3). For this review, I was provided an Eco-Charge system, including a BP-50 sealed gel-cell battery and a model 66-A smart charger.
The V3's power consumption is not insubstantial, ranging from 600 mA with the phantom power and A/D section turned off to 1 amp with everything on. In practice, a paperback-size gel-cell will run the V3 for four to six hours. A low-battery LED indicator illuminates conservatively early, giving you plenty of time to finish what you're doing before changing battery packs.
BUILD IT AND IT WILL RECORD
How does the V3 sound in real field-recording conditions? To answer that question, I built my own luggable computer for the test. This lunch-box-size, 12V, battery-powered PC is based on a VIA Mini-ITX motherboard and a Mini-Box.com 12V power-supply board. In the system's single PCI slot, I installed an M-Audio Audiophile 2496 card (good up to 24-bit, 96 kHz resolution). The entire system fits in a hefty shoulder bag.
For software, I chose Syntrillium's Cool Edit Pro 2.1 (now Adobe Audition) and its convenient hardware controller, the Red Rover. The Red Rover is a transport box the size of a paperback book, with a text display and enough knobs and buttons to let me run Cool Edit Pro without a computer screen.
After some configuring of Windows 98SE, I was able to turn the computer on and — after a minute or two — automatically have Cool Edit Pro running with the Red Rover ready to record — with no QWERTY keyboard or computer display required. Using this system, I was able to make numerous field recordings that exercised the V3's high-resolution capabilities.
THE GREAT OUTDOORS
I recorded an assortment of natural soundscapes, close-up diesel locomotives, miscellaneous Foley sounds, and a mostly acoustic jazz quartet. Briefly put, the V3 doesn't have a sound. Rather, it simply passes the mic signal as is. My experience with the V3 has been the same as with my V2. It's clean, robust, and transparent. It does what it's designed to do and does it well, and that inspires confidence in the field.
The V3's rendering of the acoustic jazz combo had great depth and transparency. In a comparison with the A/D in my admittedly lower-end Sony TCD-D8 DAT Walkman, the V3 delivered noticeably more high-frequency detail and overall brightness when both A/Ds were operating at 16-bit, 44.1 kHz. The low end it reproduced was solid and uncolored.
In the Sierra Nevada, I recorded a dawn chorus of birds, cows, and a passing freight train at 24-bit, 88.2 kHz. The results were clear and smooth. At one moment, I actually forgot I was wearing headphones.
I laid a pair of Shure SM57s alongside a railroad track to capture the grunt of a slow-moving diesel locomotive. In this case, 24-bit, 88.2 kHz resolution was overkill because the dynamic mics, their placement, and the sound source itself offered little in the upper frequency ranges. However, recordings of a bird singing and of small metallic objects — such as an ⅛-inch drill bit dropped on a concrete floor — produced a rich series of high-frequency harmonics. Using my Schoeps mics, I gathered audio at frequencies as high as 40 kHz when using a sampling rate of 88.2 kHz.
I am interested in these ultrasonic ranges for sound-design purposes. I can't reliably hear a difference between 44.1 and 88.2 kHz recordings when playing the sounds at normal speed. But stretch things down two or four octaves and the high-frequency differences become very apparent. Tiny drill bits become iron bars, then church bells. The “slow-motion” versions of the 88.2 kHz sounds have a lot more natural edge and definition, although there is also an extra octave of ultrasonic noise mixed with the desired signal. My experiments are still preliminary, but I hope to mine many riches from these high-res recordings.
So what's not to like about the V3? It does lack certain convenience features found on some other mic preamps designed for field use, such as a slate mic, a tone generator, a switchable limiter, and a dedicated headphone output. But adding those would complicate the operation of the device; I like its simplicity.
A FireWire output would be a welcome addition, making the V3 suitable for laptop use without a PC Card for digital audio. The A/D is on a removable daughter card, which allows the possibility of a FireWire or other similar upgrade, but the company has made no official announcement to indicate that upgrades are forthcoming.
An optical output would also be convenient for working with consumer-oriented gear. You can get by without one by using a coaxial-to-optical converter, such as the Fostex COP-1, but then you have another little box to deal with.
The V3's metering is excellent for music recording, but the lowest level LED illuminates at only -27 dB below full scale. When recording quiet ambiences, it would be nice to be able to meter across a larger window of the V3's wide dynamic range. Peaks of 0 dBFS are held indefinitely (they are cleared with a button press), but it would be handy to have a peak-hold function that let you choose peak values other than zero as well.
Finally, there are quite a few internal jumpers sprinkled across the circuit boards. While the manual identifies the function of each, printed documents aren't always handy in the field. I'd like a silk-screened legend on the inside of the lid, so when you popped the top the instructions would be staring you in the face.
This is a great piece of gear. It's not cheap, but it's a solid value. Did I mention the five-year transferable warranty? If you don't own great mics, I'd suggest spending money there first. But I'm making space in my field bag for a V3 alongside my V2, because I've bought the review unit. Four-channel field recording, anyone?
Rudy Trubittis a field recordist and sound designer in the San Francisco Bay Area. Visit him on the Web atwww.trubitt.com.
Lunatec V3 Specifications
Analog Audio Inputs(2) balanced XLRAnalog Audio Outputs(2) balanced XLRDigital Audio Outputs(2) AES/EBU, (1) S/PDIFPhantom Power48VPowerexternal 6 or 12 VDC (not included)Dimensions8.3" (W) × 1.7" (H) × 5.5" (D)Weight2.6 lb.
Dynamic Range110 dB (44.1-192 kHz, A weighted)Total Harmonic Distortion + Noise-101 dB (44.1-192 kHz, -3 dBFS, 22 Hz-20 kHz bandwidth)Frequency Response20 Hz-82 kHz (Fs 192 kHz, +0.1/-0.4 dB)
Total Harmonic Distortion + Noise0.0011% (@ 20 dB gain +20 dBu out)Frequency Response6 Hz-250 kHz (@ 60 dB gain -3 dB)Maximum Output Level (balanced)+25 dBuMaximum Output Level (unbalanced)+19 dBuCrosstalk-109 dB (either channel)
mic preamp and A/D converter
FEATURES4.0EASE OF USE4.5AUDIO QUALITY5.0VALUE4.0RATING PRODUCTS FROM 1 TO 5
PROS: Superior sound. Excellent build quality. Dependable performance. Stepped gain controls. AES/EBU and S/PDIF digital outputs. Built-in M-S decoder.
CONS: External battery pack required. No digital optical output. Internal jumpers not labeled on unit.