It has become common knowledge that, for optimum digital audio sound, it is preferable to use a single, high-quality audio clock reference with multiple outputs, rather than, say, employing the first device in the digital chain to drive everything else downstream in a daisy-chain arrangement.
Product PointsApplications: Recording, post production, mastering, and high-end project studios
Key Features: Standard, twice-standard, and 256 times sample rates available simultaneously, integrated video blackburst generator, LTC, video and word clock reference inputs for sync distribution
Contact: HHB Communications at 310-319-1111 or see Web Site
+ Makes studio setups less complicated and more flexible
+ Optimizes audio quality
– No 176.4 or 192 kHz (four times standard) word clock outputs
The Score: Very good single-box for generating, distributing, and synchronizing most of today’s digital equipment.
Previously I have had to use two pieces of equipment to accomplish this important task – a reference clock generator and a word clock distribution amplifier (the Aardvark Sync DA, PAR, 7/98). Also, my previous system worked only at the lower sample rates of 44.1 and 48 kHz and, since I’ve been doing most of my classical master recordings at 96 kHz for the past two years the time came for an upgrade. Enter the Rosendahl Nanosyncs box.
The Rosendahl Nanosyncs is a universal synchronizable audio clock reference with multiple outputs and integrated video blackburst. It provides six separate word clocks, one AES/EBU, one S/PDIF and four video outputs. The word clock outputs can be individually configured as fs x 1 (44.1 or 48 kHz), fs x 2 (88.2 or 96 kHz), or fs x 256 (also known as Digidesign Superclock) signals. The unit also provides 0.1 (1001/1000) and 4 (25/24) percent pull-up and pull-down rates for audio, video and film transfers.
The audio clock synthesizer can be resolved to the internal 1 ppm accurate video time base, to external PAL or NTSC video syncs, to an external audio word clock, or even to free-running LTC time code.
Technically, all audio clock signals are direct-digital synthesized by a high-speed RISC controller said to give 73 picoseconds resolution – a technique which also claims to reduce clock jitter to below measurable levels.
The rear panel first sports four video outputs that can distribute either blackburst or composite video signals, depending on the reference source. Next to these four BNC connectors are four more for connecting the reference inputs – video, word or LTC (with a thru jack). The other half of the rear panel comprises the various clock outputs: S/PDIF, AES/EBU and the first three word clock BNCs – which can be either fs x 1 or fs x 2, followed by three more which can be fs x 1 or fs x 256. In my own Digidesign-less setup, I configured the unit to do fs x 2 on the first three, and fs x 1 on the second three.
On the front panel are three switches and 20 LEDs. On the left side is the power switch; on the right side are the two other switches which – in the same manner as a digital wristwatch – influence Menu and Select. Pushing both of them together and holding for a second or so stores your configuration changes.
The various reference clocks available are internal, external PAL, external NTSC, word, TC 24 fps, TC 25 fps, TC 29.97 fps and TC 30 fps. The sample rate, as described previously, can be set at 44.1 or 48 kHz, or fs x 2, or fs x 256 by the appropriate number of Select button pushes. The aforementioned pull-ups and downs are also choices in the Select menu. The locked LED glows a bright blue when all is well. Six LEDs, one for each of the six outputs, light whenever each particular output is activated.
Rosendahl recommends that the transformer-balanced AES/EBU null sync output should be used to carry the Nanosyncs’ audio sync over long distances; the user would simply install an AES/EBU-to-word clock converter/ distributor on the other end. I have, in fact, successfully connected the Nanosyncs (located in one room of my studio) to my Aardvark Sync DA (located in another location) via their respective AES/EBU connections. The S/PDIF null sync signal can slave a low-cost DAW which lacks an external word clock input connection.
The applications manual diagrams two typical studio uses for the Nanosyncs – as the master in a post production setup, and as the hub in an analog/digital audio studio. In the former case, the Nanosyncs generates video and audio syncs from its internal time base. A video machine, a video computer card and a serial machine controller are genlocked to the video syncs, and several digital audio devices can be locked to its word and super clock outputs. The Nanosyncs’ reference clock provides the correct relationships between video frame rates and audio sampling rates. Timecode and serial machine control I/Os communicate position and transport control while video syncs and word clock signals hold the system in continuous sync.
In the analog/digital record studio example, full integration of analog and digital equipment is possible by using the Nanosyncs. When an analog multitrack tape machine is in use, the Nanosyncs resolves the digital audio clocks from the LTC track recorded on the analog tape. The timecode signal is linked through the Nanosyncs to feed an LTC-to-MTC converter for synchronizing a DAW, a digital multitrack recorder or an automated mixing console. One special feature of the Nanosyncs is that the audio clock rate corresponding to tape speed is stored and held by the unit. When the tape machine is stopped, Nanosyncs will continue to generate audio clocks at a rate corresponding to the last tape speed, thus allowing for simultaneous editing off-line. In my own scenario I always connected some sort of external input to the Nanosyncs, but could easily choose to return to internal operation mode and clock my equipment from the unit’s 1 ppm accurate and jitter-free audio clock with the push of a button.
In my most recent two high-sample rate classical recording sessions, I have used the Nanosyncs to great advantage. In the first – in which I needed to synchronize a TASCAM DA-78HR DTRS recorder and a Sony PCM-800 DTRS recorder with a Merging Technologies Sphynx interface and Apogee Electronics PSX-100 converter – I simply used it as the master clock, feeding the Apogee and Merging converters and the recorders (each interfaced with a format converter to make the Sony do TDIF and the TASCAM do AES/EBU). In this scenario, I was able to record three stereo pairs of 96 kHz data across the two DTRS machines – my standard setup these days.
I judged that the sound was a bit more “solid” using the Nanosyncs as the master clock, rather than either the Merging or Apogee units. And when I got back home and needed to play back the tapes, I had no choice – I had to use the Nanosyncs unit since I could not effect a happy sync situation when the recorders’ digital inputs were not being driven. I have often observed this common phenomenon when using my DTRS recorders at high sample rates; multiple machines seem to lock much more easily in record mode than they do in playback.
A few weeks ago, I did a three-day session at Studio Dufay for the United Nations, involving a group of young international violinists playing a great variety of music. Due to time considerations for delivery of the finished CD, I simultaneously recorded (1) four stereo pairs at 24 bits/44.1 kHz to the DA-78HR, (2) a stereo mix at 96 kHz to the Sony PCM-800/Apogee PSX-100 combo, and (3) the same stereo mix at 16 bits/44.1 directly to my trusty Studer Dyaxis II DAW. For mic preamps, mixer and converters for the eight mic channels and Dyaxis stereo mix, I used an advance unit of the new Crane Song Spider mixer.
The Nanosyncs came to the rescue one more time. Although I would have liked to use the Nanosyncs as the master clock reference, a tiny bug in my prototype mixer prevented that from happening. No problem; I simply extracted clock from one of the Spider’s individual 44.1 AES/EBU outputs, locked the Nanosyncs to it, and then proceeded to drive everything else from there. I easily synched the 88.2 kHz bit-split stereo recording (spread across all eight tracks of my PCM-800) with the eight individual mic tracks recorded at 24/44.1 on the DA-78HR, as well as the Dyaxis DAW. In this instance, the Sony/Apogee combo “thought” it was seeing 44.1 – and, in fact, it was, but I have also done several test setups with both 44.1 and true 88.2 kHz word clocks happening simultaneously. In my hybrid “standard and fs x 2 digital world,” that feat alone is some kind of miracle!
Soundwise, the Nanosyncs unit provides a clock which is at least as good as the one output from either of my Apogee PSX-100s (which previously always acted as my master clock reference) while its extreme flexibility and adaptability to my kinky multiple-recorder setups put it over the top for me. I’m sold!
Apogee Electronics PSX-100, Trak2, MOTU 1296, and Weiss DAC1 digital converters; TASCAM DA-78HR and Sony PCM-800 DTRS recorders machines; Z-Systems z-32.32r and z-16.16 digital cross-point switchers; Spectral Translator, Translator Plus, and TASCAM IF-AE8HR format converters; Studer Dyaxis II and MOTU 2408/308/1296 workstations; Yamaha DMR8/DRU8 mixer/recorder; Aardvark Sync DA word clock distribution amplifier.