The StellaDAT II 4-track Portable DAT Recorder

(Originally published in Audio Media Magazine USA)

Two oxymorons: Jumbo Shrimp. Perfect DAT.

Well, oxymorons or not, I love jumbo shrimp and the Stelladat II is the closest thing to a perfect DAT recorder that we may ever see.

The Stelladat II is the new evolution of the original Stelladat (now known as the Stelladat-I), which, since its beginning, is considered the best portable time code DAT recorder built. The original Stelladat was designed and built by the Swiss company StellaVox, until then most famous for the only portable synchronous recorder to ever give Nagra a run for it’s money. The StellaVox 1/4" analog recorder was a beautifully built machine, reeking of the finesse that Swiss engineering is famous for. Interestingly, the Stelladat chassis looks like, and has almost the same footprint as the original StellaVox 1/4" analog recorder. This makes it smaller than the Fostex PD-4 and about the same size in cubic inches as the tiny HHB PortaDat, which is a little narrower but taller. The Stelladat continued the admirable StellaVox tradition as a beautifully simple, eloquent, precise, and functional piece of art designed to work hard.

Early in its development, the prototypes of the StellaDAT I were plagued with high current consumption that drained batteries quickly and caused the unit to overheat. Financial stress within the StellaVox company couldn’t fund the refinements necessary for the Stelladat to become marketable, so it looked like the end for the Stelladat. Then came another Swiss Company, Sonosax, makers of fine audio mixers, who bought StellaVox. Sonosax refined the Stelladat circuitry and produced what became undisputedly the best of the best. The race for the number one slot was fierce, but was limited to only two other manufacturers at that time: the Fostex PD-2 and the HHB PortaDat. The only factor that kept the Stelladat I from being bought by everyone that needed a portable time code DAT was affordability. With a price tag of around $15,000, sadly, there were few purchased compared to the competition.

The new Stelladat II is truly a work of art and a marvel among portable DAT recorders. After its form-follows-function priority was met, the esthetics were added with similar care. Most of the surface is a non-glare etched and anodized aluminum finish with its protective edges trimmed with a rugged black satin finish powder coat. The machined aluminum knobs are unique, only to be found on a Stelladat, and are as sleek and precise as its understated silkscreen labeling. The front panel control buttons are large enough for cold, gloved fingers to manage while taking up no more space than necessary. All of the buttons, controls and the transport cover are internally sealed with rubber boots, and, as if that’s not enough, the top Plexiglas lid also has its own foam rubber gasket, double-sealing the deck from dust and moisture. Overkill? No. Most of the mechanical problems that we see with portable DATs in our shop are the result of dust and moisture that has entered the deck, gunking up the tiny transport gears and guide rails.

The Stelladat II has more than just a few refinements over the original than its "II" designation would suggest. In fact, it’s so much more machine that it could easily wear a new name altogether, such as the "Stella-MacDaddy-DAT". For starters, this new version has a four input mixer (one more than the Fostex PD-4), and get this: 96K sampling in 2 track mode or 4 recording tracks @ 48K! A first for DAT recorders. Of course, when in the 96K mode or the 4-track mode the tape goes twice as fast, but tape is cheap and it’s always made me nervous watching the wheels on a DAT tape turn so slowly, anyway.

At first mention of the Stelladat being a 4-track recorder, the first question is about its compatibility with standard DAT machines. The answer is that it can playback recordings made on a standard 2 track DAT, and recordings made with the Stelladat while in 2 track 44.1K or 48K mode will playback on any other DAT. The Stelladat’s 2-track 96K mode is compatible with the 96K DAT machine made by Pioneer (sold under license with other brands). The only proprietary part about the Stelladat II’s system is its 4 track recordings, so during postproduction a 4-track DAT recording requires a Stelladat II. Scoff if you like, but personally I think it’s a great way to get much more out of an already established format. Keep in mind that every standard technology that we now take for granted was at one time proprietary. The good news is that the Stelladat II is fully postproduction capable with a standard RS-422 port, and can send, receive and loop-thru word clock sync through its BNC sync connectors.

The need in film production for the advantages of 4 tracks over 2 tracks was originally addressed by the Nagra D, and those Sound Mixers who have this ability are gradually being more and more appreciated by Directors and Sound Editors. The top-shelf portable mixing consoles are also gearing up for four-track recording, so it looks like a trend that’s bound to stick.

Being a four channel recorder mandates that it have four inputs, but the Stelladat II goes the extra mile with a true 4 channel mixer, fully functional even while in the 2 track recording mode. With the best mic pres of all other portable DATs, it is also the only one that still has "T" mic power available; an option shared only with the Nagra D. Each input has gain selections of 0db to 70dB in 14dB increments and a 10dB trim pot. But the mixer lacks full range faders on each input, so it is obviously intended to be more of a tracking mixer as opposed to riding gain on the fly; a design choice that I’m not yet settled with. Relating to film production, I’m imagining a close quarters car-towing scene where, ideally, in the interest of time and space, the recorder and microphones are all that’s needed. But if I want to bring up a single microphone for a short piece of dialog and quickly bring it fully down again, an external mixer would still be needed for this simple everyday task.

With an incredible amount of user friendliness in a small package, the Stelladat II has time code in and out on balanced XLR connectors and also on the industry standard 5 pin Lemo for easy interfacing with Nagras and the Origin-C camera time code box (thank you very much). Digital I/O’s are available on AES/EBU XLR connections as well as SPDIF on optical connections.

The Stelladat II, like its predecessor, uses the NP-1 rechargeable battery and now has an integral internal battery compartment. Power management has been improved once again on this new model to a consumption of only 10-15 Watts and the four analog inputs can be turn off independently to conserve battery life. Even at full tilt, drawing 15 Watts, a standard NP-1 will keep it running for about 1-1/2 hours continuously and much longer when factoring in typical standby intervals. One of the new 50-Watt hour Nickel Metal Hydride NP-1 batteries could feasibly power the Stelladat II an entire production day.

Other improvements include a backlit LCD display, replacing the LED display on the original that was impossible to read in direct sunlight. The new display is smaller than any of the competition’s, but still has much greater resolution, with increments of less than 1 dB. No more guessing about what level your setup tone actually is.

USER OPTIONS

One control on this machine that draws a lot of attention is its cute little joystick. The joystick accesses the menu and selects the user options and setup parameters, greatly simplifying this process compared to other machines. Press it like you would a button to see the menu on the LCD display and then use it to scroll up, down, back, and forth through the menu tree. Once a selection has been altered, press it down again to store the change. Because of the fine resolution of the display, the menu, function, and option descriptions are actually spelled out full length in English. Imagine, being able to setup user options without a cheat-sheet! No more having to decipher abstract abbreviations made from seven segment character displays and no more having to remember three digit codes for user options.

The available user options include all of those found on the other portable time code DATs plus a few that many of us have been wishing for. In the setup mode, the meter display can be selected to have the ballistics of a VU meter or a Peak meter, and the meter scale can be chosen either "DSP Nominal" (full scale being "0"), or the "DAT Standards" of -12dB or -18dB with a "0" where the zero VU reference is.

All of the needed options regarding time code frame rates are available in drop and non-drop. If scrolling through and selecting the time code options bores you, you can simply select one of the "Default Values" settings and the changes are set automatically. For instance, if the "Film USA" default is selected, the input and output time code is set to 30frms non-drop; "Video USA" changes all settings to 29.97 drop-frame and "Video Europe" changes the settings to 25frms.

With film production sound In the US we have to go through mental gymnastics when considering the pull-up and pull-down process (altering the speed by .1%) in anticipation of the telecine transfer. Both the Fostex PD-4 and the HHB PortaDat have features that allow this to be dealt with, but both only allow in increase in speed of .1% and only then when in the 48K mode. The Stelladat is by far the most comprehensive in that it allows the record and playback speeds to be adjusted up or down by .1% whether in 44.1K, 48K, or 96K sampling mode. Why? Because it’s the right thing to do and it’s the Stelladat.

Ever been afraid you were going to accidentally push the tone switch during a take? Ever done it? Ever lied to the director about why the take was no good? Well, typical of the user friendly options the Stelladat offers is the ability to mute the tone during recording, eliminating the possibility while still being able to check settings during pause. So, after you have recorded the setup tone at the head of the tape you can choose this option and stop worrying. The same feature is available for the internal slate mic.

Moving from analog recorders with mechanical levers that make them go to machines with microprocessor brains may take a few cups of coffee, but also allows for some interesting options. The Stelladat makes use of its intelligence with five "function" switches across the front of the deck top. These switches are normally REC, PLAY, STOP, RR & FF, being redundant with the larger buttons on the front panel, but these switches can also be programmed for slate mic, tone, and 4 separate locate markers for playback cues.

Other examples of how the Stelladat leads the pack in terms of consideration to the needs of film and television production sound include the time code generator and monitoring features. When Fostex and HHB introduced their portable time code DAT machines there was no allowance for keeping the time code generators running during battery changes, headphone monitoring was limited to L/R stereo only, and there was considerable time code drift (1 frame in four hours on a good day). These problems have since been remedied with retrofits and after market mods, but still…come on guys. The Stelladat II will need no such mods. The time code generator will run continuously from a dedicated internal battery for years even without an NP-1 or external power. Time code accuracy is better than 1 frame in ten hours and can be ordered with a High Stability Crystal for a drift of less than .1 (point one) frames in ten hours. Headphone monitoring is completely selectable for any needed configuration, including M/S decoding. See, it can be done.

From layout and workmanship to features and user friendliness, the Stelladat II is easily the standard of excellence for all portable time code DAT recorders, and if price were left out of the equation, no one would even consider anything else. The big question for this machine is the life expectancy of the DAT format in general because of the yet-to-be-determined acceptance of portable tape-less formats. In this regard, a big plus for the Stelladat II is that it is the only option that can record four channels and still produce recordings that are compatible with the present state of all post production facilities, while tape-less formats in post production are still in the very early "gearing up" phase.

Only history knows the fate of the dat format, but for now, and I predict for some time to come, the Stelladat II is a very viable machine, nicely bridging the gap between the established dat format and the growing need for portable 4 track recording. Because the Stelladat II is the only choice for all that it has to offer, thank goodness the choice is such an awesome one.

–Glen Trew