Your browser is out-of-date!

Update your browser to view this website correctly. Update my browser now


Rosendahl bonsaiDRIVE

Its concept involves having a standalone, synchronizable hard disk recorder as the portable media storage device, instead of merely a removable hard disk of comparable size and weight.

(click thumbnail)For most of the time I have been an audio engineer I have brought a camcorder to recording sessions. Even back in 1970, I used a GBC monochrome surveillance video camera so I could see what was going on during sessions, since the control room was often very remote from the musicians I was recording. This monitoring setup eventually evolved to color and, from the mid-‘90s onward, was upgraded to a mini-DV camcorder that ran throughout the sessions, fed with audio from the mixer itself.

As the quality of these videos improved and DVDs became more commonplace, the classical musicians I was recording started requesting session DVDs instead of CDs; apparently they enjoyed watching themselves while they made their editing decisions. I always had to explain that the camcorder audio — although fed from the same mix as the master recorders — suffered from going through the audio inputs and ADCs in the camcorder and, consequently, didn’t sound nearly as good as the “real” audio. Even a “professional” unit — a $2,500 Panasonic AG-AVDC30 with its XLR mic/line inputs — still manages to mangle the audio pretty severely.

When I first saw the bonsaiDRIVE at the NYC AES show two years ago – as it played back a looped infomercial featuring Fritz Rosendahl himself – I was intrigued. So by the following summer I had succeeded in borrowing one from its distributor just in time for a yearly trip to Atlantic Canada’s Prince Edward Island for the Rollo Bay Fiddle Festival. I subsequently purchased this review unit and have found it invaluable since.


The $1,990 bonsaiDRIVE is a high-quality portable video and multitrack audio hard disk recorder aimed at the film and video postproduction, video assist and multimedia markets, as well as the video monitoring and security industries. Its concept involves having a standalone, synchronizable hard disk recorder as the portable media storage device, instead of merely a removable hard disk of comparable size and weight.

The unit reviewed here runs on 12 volts DC (the company’s other model works on mains AC only) and records uncompressed 4:2:2 PAL or NTSC video together with 10 audio channels to standard IDE hard disk drives. No drive is supplied with the unit, but installing (or removing) one takes only a minute or two. I first put in a 120 GB IBM/Hitachi drive, but quickly replaced it with a 400 GB Fujitsu unit when I became confident and needed longer recording time.

Rosendahl uses a Huffman codec providing a lossless video compression ratio of 2:1, which is said to result in a superior video picture and a data transfer rate of 10 Mbyte/s, well within the capabilities of standard IDE drives. The audio channels are arranged as an analog stereo pair and a digital eight-channel ADAT stream, and are 48 kHz at 24 bits. Professional synchronization I/Os include timecode, Sony nine-pin remote control, MTC, MMC, video sync input, Word Clock output and GPIOs, allowing flexible integration in postproduction or multimedia installations.

The front panel can be removed from the machine and used as a separate remote control with a standard 9-pin cable connection. A second nine-pin connector allows an additional external machine controller to be connected.

All configuration menus and settings are implemented as an interactive on-screen video display, together with insertion of timecode and audio levels in the program video, if required. On sessions, I just bring along a little LCD monitor screen, which I perch on top of the unit. As long as the bonsaiDRIVE is in Stop mode, I can mess with its on-screen menus. The possibility of inserting vertical, multi-colored level meters (either stereo or multi-channel—if I’m sending multi-channel digital via the ADAT connector) is extremely helpful, and I always leave it turned on while recording. Back at the studio, I simply go to the appropriate menu item and turn that function off.

Since each frame is recorded individually, jog, shuttle and playback from 0 to +/- 200 percent can be easily accomplished with results similar to that from a professional, analog VTR. Sync audio is output in all modes, including reverse, jog and shuttle, further giving the impression of playback from tape. All recordings are organized as unique clips. The timecode start value and frame rate can be selected independently of the recording format.

The bonsaiDRIVE’s firmware can be updated through a computer serial port (MIDI or COM). Loader programs for PC or Mac, as well as the firmware files, are available in the support section of Rosendahl’s website. (In fact, I suggest the reader visit in order to download the bonsaiDRIVE’s manual and pertinent information.) As of the writing of this article, firmware 0.34 was released, which supports audio insert, new track arming and assemble record modes, a new bonsaiDRIVE codec, edit capabilities with copy and paste commands and audio crossfade processing, and programmable video to picture offsets.

The unit’s front panel has 10 square pushbuttons. They perform all the functions of a standard tape or video machine transport remote — including two dedicated (and storable) locate buttons — and also include a menu button (switching the on-screen display on and off), and one button that puts the machine under remote (Sony P2) control. A shift function (press Stop while pressing any second button) makes the leftmost eight buttons perform the functions indicated in white-on-black above the black-on-white buttons.

The rear panel offers an array of goes-ins and goes-outs. Over on the left, we have the four-pin XLR that provides a typical video guy’s kind of 12 VDC input. Since this unit has this functionality (Rosendahl also makes a less expensive straight 120/240 VAC version), I’ve also purchased a video-type battery to power it off the grid. Then comes the pair of ADAT ODI I/O connectors and, then, a set of MIDI I/O jacks for MTC synchronization and MMC control; they can also be used for the aforementioned bonsaiDRIVE firmware updates using MIDI SYSEX.

Now we get to the “regular” jacks; there are Word Clock output and sync input BNCs, timecode I/O RCAs, audio I/O RCAs (menu-adjustable to various operating levels — very helpful) and, finally, six BNC jacks across the bottom row, which — if you follow the labeling carefully — can be used for composite, component or S-Video I/O. There’s also (on the review unit) a blank panel where the SDI option card might be installed, were I to have the auxiliary connecting equipment and available cash to do so.

A new Gigabit Ethernet option board should be available by the time this article is published. It will allow the user to transfer bonsaiDRIVE QuickTime movies and broadcast .wav files to and from any other computer or bonsaiDRIVE via FTP, using a new codec that Rosendahl will provide. This option board will go inside the unit and will be an IDE slave device at the hard disk IDE bus, hooked to an RJ45 connector on the back panel. For older units, Rosendahl will provide a new back panel with extra breakout connector.

Fast FactsApplications
ENG, postproduction, studio

Key Features
Very small; records and plays back 10 channel audio (stereo analog plus ADAT-ODI digital) and video (composite, Y/C, component or, optionally, SDI) simultaneously

$1,990; $2,290 for 12 VDC version; optional $595 SDI interface

HHB Canada | 416-867-9000 |



  • Very high quality stereo audio ADC and DAC (at 48 kHz/24 bits)
  • ADAT ODI permits eight more channels at 48 kHz, or four S/MUX channels at 96 kHz, flexible video I/O
  • Elaborate menu structure permits many system tweaks and adjustments, including on-screen multi-channel meters


  • Video and audio must be output (via analog, SDI or ADAT ODI digital) in real time due to proprietary hard disk format

I know of no other such simple, elegant and easily portable way to capture high-quality video and multi-track audio simultaneously.In Use

Where shall I start? For an example, let’s go to the previously mentioned gig. It was a choral concert where the video became as important as the audio. Good thing I’ve now got a secret weapon to preserve audio in this world where video has established a significant footing!

For recording and space considerations I established a signal chain that all fit on a little table underneath a Manfrotto tripod. First was a vacuum tube stereo Neumann SM69 (with 0.9-micron Stephen Paul diaphragms) out in front of the chorus, feeding the tiny Apogee Mini-MP stereo mic preamp back on the little table. I split its audio output towards both the bonsaiDRIVE and the XLR inputs of the Panasonic camcorder, whose S-Video (Y-C) output was also sent to the bonsaiDRIVE. And, believe it or not, I was 100 percent off the grid; no AC was available so I ran everything from batteries, including the Neumann tube mic!

The recording came off just fine, and I didn’t need any safety “backup” onto the camcorder’s DV tape and its yucky audio tracks. Back at home in Studio Dufay, it was time to sweeten the audio and produce 50 DVDs over the weekend. No problemo — Steve Jobs was to the rescue via a 1.5 GHz G4 12-inch PowerBook running iMovie and iDVD. Since one still has to playback the bonsaiDRIVE’s recording in real-time via analog, I used the ubiquitous, bargain-priced Canopus AVDC-100 as the computer’s audio/video front end.

To keep the audio in sync with the video, I simply clocked the PowerBook’s CoreAudio (locked to a M-Audio FireWire 1814 interface used mainly as the digital interface driving an external Weiss DAC1 for audio monitoring) from the bonsaiDRIVE’s Word Clock output BNC connector. I inserted a pair of Rupert Neve Designs Portico 5033 EQ channels and a Manley Vari-Mu dynamics processor into the stereo audio signal path between the bonsaiDrive and the Canopus interface, hit the play button on the Rosendahl unit, made a few mastering-type adjustments, and started copying the concert into iMovie.

As you might expect, the audio results sounded pretty awesome; “awesome” was actually the exact word the first choir member who heard a production DVD played back through a TV set, no less, used to describe the sound. The video lost no obvious resolution that I could notice on a 23-inch Apple Cinema Display when comparing the original DV tape and a copy of the Rosendahl recording, which speaks volumes to the high quality of the “lossless” compression used in the bonsaiDRIVE.

I’m sure that, had I owned a more expensive camera with true component outputs, the video results would have been better. Further, if I had had a real SDI camera at my disposal (and had invested in the SDI option card for the bonsaiDRIVE) and had also purchased an expensive SDI computer interface, the quality of the video might have matched the quality of audio. But, as it was, the video I supplied it (and which the bonsaiDRIVE maintained) was of “standard DV issue,” which was fine with me. The audio I supplied (also maintained perfectly) was of “high-end, professional quality” — the original goal in considering this system in the first place.


As far as I know, the Rosendahl bonsaiDRIVE has no direct competition in the worlds of professional audio or video. If you need a means to record high-quality multitrack audio alongside your video, then I see simply no alternative other than lugging a computer and various expensive interfaces to your location recording sessions. In this context, the bonsaiDRIVE is actually quite a bargain. If all you (like yours truly) want is to have awesome audio accompanying standard DV-quality video, then the Rosendahl bonsaiDRIVE is a godsend.