The Rosetta 800 ($2,995), Apogee’s newest 24-bit multichannelconverter, offers eight channels of A/D and D/A conversion, flexiblesync capabilities and Apogee’s proprietary UV22HR wordlength reductionand Soft Limit dynamics processing. Although the 800 bears the Rosettaname, the new unit uses different converter and clock circuitry thanthe original 2-channel Rosetta 96 A/D. The Rosetta 800 shares manyanalog design improvements from Apogee’s high-end SE (Special-Edition)converters and functions (including D/A conversion and the ability tosync to external clock) that are not found in the original Rosetta.
A ROSETTA BY ANY OTHER NAME
Three D-sub connectors provide eight channels of balanced (+4dBu)analog and eight channels of AES/EBU I/O (supporting both single- anddouble-wide formats). Optional XLR breakouts are available. Two pairsof Toslink connectors provide eight channels of ADAT- or S/MUX-formatins and outs.
A rear option card slot accommodates Apogee’s X-Series Expansioncards ($595/each). The X-DigiMix card provides direct interface to ProTools TDM PCI cards. X-HD and X-FireWire cards should be available nextmonth. Word clock I/O (on BNCs) and a detachable IEC AC cord round outthe rear panel. The word clock input is non-terminated; users shouldfit a terminated T connector on this input when slaving Rosetta 800 toexternal word clock.
The 800 can sync to internal crystal, external word,single/double-wide AES/EBU, ADAT Lightpipe (including S/MUX) or optioncard clock signals. The unit supports up to 96 kHz, but a $3,995/base192kHz version is offered. Rosetta 800 can operate at any samplingfrequency that’s a multiple of where its word clock input is locked. Itcan also output word clock at a rate multiple of which its convertersare operating.
Two simultaneous 8-channel audio streams — one routed todigital outs, the other to analog outs — are possible withflexible routing. For the first multichannel stream, you can routeanalog ins simultaneously with digital ins of any one supportedformat in channel pairs to corresponding channels of digital outs. (Alldigital outs are active; the 800 automatically handles formatconversions.) The second multichannel stream accommodates analog anddigital sources (one digital format at a time) routed to like-numberedchannels of analog outs in channel pairs.
Apogee’s UV22HR processing can be applied globally to all digitaloutput signals to reduce word length from 24-bit to 16-bit. Soft Limitprocessing (proprietary analog domain dynamics processing) can also beapplied globally to all analog inputs or disabled. Soft Limit can’t beactivated independently for each channel. That said, the processingsounds incredibly transparent. Apogee’s Soft Limit is easily myfavorite analog limiter.
All eight channels have signal presence and “over” LEDs,although power users will bemoan the lack of external calibrationtrims. Only three fixed calibration levels are possible. The default is+4 dBu = -16 dBFS. Internal jumpers provide two alternatives: Onecalibrates +4dBu levels to -20 dBFS, and the other produces -13 dBFSfor semi-pro -10dBV levels. This limits the choices for analog inputsensitivity, but still offers headroom. Very quiet sources required atleast 65 dB of external preamp gain for the 800 to achieve 0dBFS peakreadings. Apogee plans to offer a retrofit calibration pot card thatwould fit over jumpers; however, accessing the card’s trims will stillrequire popping the top panel.
For one test, I sent a kick drum track — previously recordedin Digital Performer — on a round trip through the Rosetta 800’sD/A and A/D circuitry. The Rosetta 800 reduced — by a hair— the lower midrange frequencies in the processed track;otherwise, the track copy was indistinguishable from the original. Thedifference was so subtle that it was almost inaudible. Performing thesame A/B test with a flamenco-style nylon-string guitar track, theoriginal track had slightly more depth than that processed by theRosetta 800’s AD/DA. These tests confirmed the uncanny accuracy of the800’s converters.
More tests involved recording a capoed acoustic guitar using aspaced pair of DPA 4011 condensers with a Millennia HV-3D preamp, andon an electric bass guitar using a Millennia TD-1 Twin Direct RecordingChannel. With each box synched to its own internal clocks, comparingthe A/Ds in the Rosetta 800 to my Rosetta 96, I found that the 96sounded a bit fuller in the lower mids, more understated in the lowerhighs, and exhibited a slightly wider stereo image and a tad moredepth. The 800’s (A/D and D/A) dynamic range spec is 114 dBA, althoughthe depth that I heard suggested a more impressive number. The 96’sA/Ds sounded a little more fluid and analog-like on acoustic guitarthan those in the 800, perhaps due to the 96’s slightly greater depthand fuller low mids. On electric bass, the 800’s A/Ds made the tracksound present, clear and tightly focused, while the 96 produced a moresoft and pillow-y sound; the two yielded a very similar bottom end.
Up next were recorded acoustic guitar tracks. When I synched theRosetta 800 to Apogee’s Big Ben Master Digital Clock, the tracks had asweeter, more fluid high end, a slightly wider stereo image and anoticeably enhanced depth compared to those recorded with the 800synched to its own internal clock. The combination of these two boxessounded downright incredible.
The Rosetta 800 sounds outstanding and offers useful features andfunctions beyond AD/DA conversion. Every bit worthy of the Apogee name,the Rosetta 800 is a winner.
Apogee Electronics, 310/915-1000, www.apogeedigital.com.
Michael Cooper is the owner of Michael Cooper Recording, locatedin beautiful Sisters, Ore.