Audio adventures in SCSI DAT

[Kris]

I've always wanted to audio enable a SCSI DDS drive but it was always one of those 'maybe one day' projects until Nick (Beechwoods) reinvigorated my desire towards the end of last year. I've always been worried about buying a second hand thrashed DDS drive, and that's put me off a little. However, one fortuitous ebay purchase later, I was the proud owner of a brand new Sony SDT-9000 DDS-3 drive.

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Cost? 99p Yes, that's under a pound, and even with postage, it still came to under £8.00

Although it would have been a lot easier to mount this internally, I wanted it as an external drive. Fleebay to the rescue again with a brand new self-powered SCSI external enclosure, and a new mounting kit.

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And an Adaptec 2940 SCSI PCI card.

And this is where I had to put my thinking cap on. The Sony DDS drive is 50 pin, the SCSI enclosure has Centronics connectors and the SCSI card has a 68 pin external connector. So what I did was buy a 68 pin to 50 pin adaptor and a two meter 68 pin cable. The cable plugs into the SCSI card at one end, and into the adapter at the other. The adapter plugs into the back of the Sony drive. The only problem with this is that there isn't enough room in the enclosure behind the drive to plug in the cable and adapter. So I had to move the power supply in the enclosure, loose the back panel and hard wire a mains lead in, with a flying mains switch wired into the cable to turn the unit on and off.

I also installed some 12V blue LEDS into the drive which light up when the power is on. Not that I particularly like Blue LEDS, but it does match the LEDs in my External Hard drives. Oh, don't forget to say hello to Spongebobs friend Gary the snail

That was the easy bit. Now to get it working! Three things are needed software wise. Drivers, firmware, and software to read the audio off the DAT tapes.

DDS drives, although they use the same (similar) tape and mechanisms as DAT drives, are not audio capable out of the box. Not all DDS drives can be turned into audio drives, and even those that can, it's a bit hit and miss and there's no guarantees. Although the Sony SDT-9000 can be audio enabled, apparently there's 4 versions of this drive, not all can be audio enabled, and you don't know which version it is until you buy it. Good luck!

Thankfully, I bought a good 'un

I installed the Adaptec ASPI drivers. But even this wasn't straightforward. The latest drivers (V4.8)didn't want to play ball, and neither did the previous version (4.71). 4.6 did though and it's quite stable (in my Xp SP3).

Some people can't get any of the standard ASPI drivers to work, in which case there's FrogASPI. It's all trial and error!

I then upgraded the standard Microsoft DDS driver with the Sony Version.

One quick mention about SCSI. It isn't plug and play like USB. Each connected device has an id which must be set manually. The SCSI card is usually id7 and my DDS drive is id0, and it's on bus 6. Also, each connected device needs to be electrically terminated. Thankfully though my SCSI card is self terminating. Anyway, on with the show. . . .

At the back of the DDS drive there's various jumpers that need setting, and on the bottom there's 4 dip switches. It took me some investigation & web searching to find which settings to use . . . If you use the wrong ones you risk blowing the drive up, so it's important to get it right!

The standard DDS firmware (mine was 6.01) doesn't work with audio DAT. So the drive has to be flashed. So using the Sony Tape Tool I flashed the drive to audio firmware 12.2. It worked. If you get this far then the DDS drive will probably work as an audio drive, but remember, there's no guarantees, even if you do get this far! Also once you have flashed the drive with the audio firmware, it's no longer a data drive. By-by DDS, hello DAT [edit: apparently the drive is still data capable, see Nicks post below]

Software. You need this to be able to play and save the tracks on your DAT tape! Now because audio DAT from DDS drives was never supported, there's no official software out there. But there is a fair amount of freeware, alpha and beta, and there's even a prog still in development (windat). because I have a windows PC I don't know about what MAC software there is, but there are some progs written for Mac OS.

For windows there's 4 progs. Dat2Wav, the most common, is a command line prog that will let you play, record to and transfer audio from DAT onto your PC as .wav files. vdat is an elusive windows UI prog which is usually only available in the trial version, however there's now a fully functioning version of VDAT available free. DAT Deck is the third windows prog. It's an alpha build and development ceased years ago, so most of the functions don't work, but it's ok if you only want to play DAT tapes that were recorded in 48kHz.

The fourth Prog is also a windows UI prog, and it's a new one that's still in part-time development. It's called WinDAT and allows you to save the contents of a DAT tape to .wav

Here's a screenshot of all four progs in action:

Actually, I'm very lucky because all four progs work fine for me. There's no guarantees in this game and some progs work for some people, some for others. Again, this is all trial and error. It depends on your drive and SCSI card. One problem I have found is that sometimes if you put in a tape that's been fully rewound the drive won't recognise it. This is because DDS tapes have a special leader tape at the start which DDS drives recognise. Ordinary DAT tapes don't have this special leader tape. So I just fast forward the tape past the leader

Because Dat2Wav is a command line prog, and the one I'm using most, I've written some batch files, with links on my desktop so two clicks and it opens the prog and does what I want it to, either play a tape or save the contents as individual tracks or as one complete .wav file.

If anyone wants the Audio DAT icons, or details on how to make the batch files, just pm me.

But how does it sound?

I have compared the sound from the computer DAT drive with my Sony DTC-77ES Dat recorder. Using the coax out from my motherboard into the 77ES, I can make a direct comparison. But there's 7 or so metres of 75ohm coax to take into account between my pc and the 77ES.

I'm afraid I'm still in the WOW! stage. I've wanted a SCSI DAT drive for years and I'm still like someone let loose in a sweet shop with it all. I think this is maybe affecting my perception of the sound quality.

Listening both through headphones and the speakers, and trying to match the levels as much as possible, I think the SCSI DAT drive sounds more immediate, more up front. It appears to have more sparkle, deeper bass, and clearer mids. Comparing the two DAT transports (which is in effect what I'm doing), the SCSI DAT drive sounds better. However, I'm also aware that the sound is akin to a slight 'loudness' curve/button. Because I'm still in the WOW! phase, at this point I don't feel I can make an objective comparison.

Overall though, it's been a very exciting and fruitful project for me, and I can at last transfer DATs directly to my PC at 4x speed. All for a total cost (including postage) of £38.36. I'm aware that I've been very lucky in the fact that it works, and works as well as it does. Not everyone is so lucky! And I'm very grateful to Nick (Beechwoods) for inspiring me to do this.

The software, including the elusive VDAT prog and the new WinDAT prog is available from http://tech.groups.yahoo.com/group/datheads2wav/ which is a technical group for those trying to audio enable DDS drives.

Kris.