Field Test: Universal Audio Model 2192Universal Audio's Model 2192 Master Digital Audio Interface combines feature-rich design with impeccable audio quality. 1/01/2004 7:00 AM Eastern
Universal Audio's Model 2192 Master Digital Audio Interface combines feature-rich design with impeccable audio quality. Priced at $2,795, the 2192 offers two channels of AD/DA conversion, flexible routing and a word clock generator/distributor. Universal Audio's traditional commitment to audiophile analog sound is reflected in the analog signal path, which features DC-coupled, fully dual-differential, matched-FET and all-discrete Class-A circuitry. To avoid phase distortion and image instability, no capacitors or DC servos are used in the signal path.
The 2192's A/D conversion is always 24-bit with support for 44.1/48/88.2/96/176.4/192kHz sampling rates. Digital audio appears at all outputs, with 176.4/192kHz audio carried on AES/EBU single- or dual-wire (or ADAT optical with S-MUX interleaving). S/PDIF is fully implemented, including 24-bit, 192 kHz. You can route signal straight through the 2192 to monitor the signal at the inputs.
Digital audio from any of the unit's inputs (AES/EBU, S/PDIF or ADAT S-MUX) can be converted to analog. Clock source can be internal from a digital audio source or from a separate external clock. A front panel lamp indicates lock status. An internal clock conditioner keeps external source jitter from affecting the internal clock. There are two word clock inputs and four word clock outputs. The unit can also lock to AES/EBU, S/PDIF or ADAT S-MUX, so the 2192 can serve as a handy clock distributor for the small studio or mastering setup. It also supports subclock and overclock, so, for example, you can use a 48k clock while the unit is converting at 192 kHz.
A Clock knob specifies the master clock source: Internal, Word 1, Word 2, AES-S/PDIF and ADAT. Subclock (½x or ¼x) and overclock (2x and 4x) synchronization are supported for converting at submultiples and multiples of the sample rate. Super clock is not supported.
The Sample Rate knob selects from 44.1/48/88.2/96/176.4/192 kHz. Locked to external clock, the 2192 supports a ±12.5% varispeed lock at all sample rates. The unit's sample rate is determined by the clock and Sample Rate knob selections, except when the clock source is set to AES-S/PDIF. In this case, the sample rate is automatically detected and the sample rate knob has no effect. The 2192 does not support sample rate conversion and won't sync unrelated clock rates; for example, a 44.1kHz digital clock with 48kHz digital audio.
An Analog Output/DAC Source Select knob specifies the digital source (AES-S/PDIF, ADAT or ADC) for the D/A converters and the analog outs. The AES-S/PDIF setting is further controlled by the AES-S/PDIF switch to the right of the knob. When ADAT In is selected, the ADAT optical input is routed to the D/A converters and to the analog outputs; S-MUX mode is determined by the sample rate knob. When ADC is selected, the digitally converted signal at the analog inputs is routed to the D/A converters and analog outputs for “true confidence” monitoring.
The Single/Dual switch specifies whether AES/EBU single- or dual-wire mode is used. For our needs, this switch is one of the 2192's most attractive features. We often have to route audio to Pro Tools, which uses dual-wire mode for 176.4 and 192 kHz. This switch does not affect S/PDIF input, but in dual-wire mode, the S/PDIF output will transmit the same signal as the AES/EBU “A” output.
The Digital Outputs Source Select knob specifies the signal that is routed to the digital outputs, with the same selections as the Analog Outputs DAC Source Select knob. The knob is generally left at ADC except during transcoding, and any source that is selected is automatically routed to all digital outputs simultaneously.
The back panel AC input leads to an internal auto-sensing, filtered, multistage power supply that supports 100 to 240 VAC and 50 to 60Hz power. There are four transformer-coupled balanced XLRs for digital I/Os. The left pair, AES “B,” handles one channel of I/O when the 2192 is in dual-wire mode, and it replicates AES “A” output in single-wire mode. (AES input B is used only in dual-wire mode.) AES A handles up to 192kHz stereo I/O or one channel of I/O when the unit is in dual-wire mode. Input bits (SCMS, pre-emphasis, pro/consumer, etc.) are ignored. SCMS and pre-emphasis bits are not set on output, but pro/consumer is set to professional.
There are eight balanced connectors, including analog and AES/EBU digital I/O, and they can individually isolate Pin 1 from ground via an internal jumper block. The 2192 adheres to the universal Pin 2 Hot standard.
Dual-stacked RCA connectors handle S/PDIF with unbalanced, transformer-driven output and AC-coupled input. Input/output bitstreams are set the same as AES/EBU. When the clock knob is set to AES-S/PDIF and the digital outputs knob is not set to AES-S/PDIF, the S/PDIF signal is used for clocking only.
Six BNC connectors handle word clock. The first four are 75-ohm, 5-volt CMOS drive outputs; the second two are AC-coupled, 75-ohm inputs. Clock delay from input to output is 50 nanoseconds maximum and is negative-edge-aligned when synchronized at a multiple or submultiple rate.
ADAT optical I/O comprises two Toslink connectors with dual in-line reinforced optical TX/RX. Channel usage varies from two for 44.1/48 kHz to all eight for 176.4/192 kHz. Like S/PDIF, the ADAT input can be used for clock only.
Connected to any piece of my digital gear, I was pleased when the 2192 accepted the signal and could route it elsewhere. The excellent manual contains “recipes” for routing, as well as diagrams for mastering and DAW setups, including Pro Tools|HD. I could use it for dual-wire 192kHz projects with my Pro Tools Accel system and easily switch it over to ADAT S-MUX or S/PDIF from my RME Hammerfall 9652 Nuendo system. I ran into S/PDIF failure with another converter when routing it from the RME, so I was glad to see that the 2192 locked immediately and performed flawlessly. As you can transfer audio between AES/EBU, S/PDIF and ADAT-SMUX in real time, the 2192 is great for transcoding.
The 2192 is hot — literally. In rackmount installs, leave space above and below the unit. When stacked in open air and separated by ½-inch spacers, the top was much cooler than when it simply rested on a flat surface.
Ten-segment LEDs monitor stereo input and output. They are tied to the converters, not the analog trims. The red clip segments are driven by digital circuitry; the other nine segments are driven by analog metering circuitry and calibrated to reflect digital signal. The unit is factory calibrated at 0 dBFS = +22 dBu (and -18 dBFS = +4 dBu), but this is adjustable using rear panel analog line trims next to each I/O XLR. I've long been an advocate of adjustable trims for calibration. It's a must for critical mastering situations and for times when engineers need to have converters set at maximum sensitivity to capture low-level detail in the analog source. Still, I wish the trims were located on the front. For those who calibrate early and often (rather than “set and forget”), it would make life easier.
I'll hate to send this box back to Universal Audio. We had some great sessions with it. For recording a guitar directly into Pro Tools, the 2192 mated wonderfully with my Millennia Origin STT-1. Jazz chords were rich and creamy, while chicken pickin' chits were snappy without being overbearing. All sample rates sounded great, but I found that the more I use 192 kHz, the more that “something extra I can't describe” hooks me into using loads and loads of disk space.
The crème de la crème example of the accuracy and beauty of the 2192's conversion capabilities was when I used an AKG C426B dual-capsule condenser mic in X-Y mode with figure-8s. I ran this through John Hardy M-1 preamps. JamSync, which I co-own, has a room upstairs for recording guitars and drums. It's moderately reflective with plaster walls and various movable acoustic “room shapers.” I tracked using my old Fender Princeton and favorite hot-rodded Strat, experimenting with amp positions, as well as checking the system with vocals. I also recorded some drum tracks with the mic in various positions.
As I listened back, several things caught my ear: the clarity of the instruments, the depth and breadth of space, and the richness of detail. At 192 kHz, I was amazed at the results. You could practically hear the ridges of the cymbal as the stick was slowly scraped along it to produce a shimmer of sound — gorgeous. It was one of those moments that reminded me of the reason I became an audio engineer: for the sheer joy of being able to hear the stark beauty of sound.
Another telling moment came when my partner, Joel, walked in the room and was shocked to find out that I wasn't playing, but listening back.
Universal Audio enters the converter market with a clear-cut winner, the Model 2192 Master Digital Audio Interface. The 2192 provides routing flexibility with exquisite sound. Needless to say, I'd be very happy if Universal Audio would bring out an 8-channel version of the 2192. Until then, we'll have to drive four of the units via word clock for surround sound, a small sacrifice to make for achieving such excellent results.
Universal Audio, 831/466-3737, www.uaudio.com.
K. K. Proffitt is the chief engineer at JamSync, a Nashville-based studio specializing in surround sound production.