whats DAT all about

[FX23]

whats the crack with dats? all my DAT recorder has to do is look at a DAT tape and it chews up.

whats the point?

[HideawayStudio]

whats the crack with dats? all my DAT recorder has to do is look at a DAT tape and it chews up.

whats the point?

There has been a lot of DAT bashing in the last few years. DAT is now an old format, yet it is still a great digital format, BUT, like all helical scan tape based systems, it's only great if the gear being used is very well built. It simply isn't fair or right to slag off a format that was the de facto standard for CD mastering for a very long time in the CD audio industry. DAT following the dreaded F1 PCM days where, incidentally and very sadly, many master tapes were lost due to oxide stripping on uMATIC tapes.

It's primarily the domestic grade DAT machines have become bad news with age - just like domestic video recorders. On the other hand the semi-pro and professional machines have proven the test of time in many cases due to their direct drive mechanisms. My DTC77ES is a semi-pro machine which I've owned since new from 1992. The machine cost me £1200 which was a h**l of a lot in those days. It's a 4 head, 100% direct drive machine ie. there is a motor for every fuction and has never missed a beat. The wrap/unwrap function and all cueing functions are therefore performed with variable speed and torque servo motors under micro control. The audio and digital stages feature separate mains tranformers, everything is shielded to the hilt and the chassis is built like tank. This is in sharp contrast to the cheap belt driven junk that was sold into the domestic market. Unfortunately SONY was known for it's contrast in quality between its pro and domestic gear and this is where it really showed.

Unless a pro machine has a lightship mileage on it it should be fine provided it's used with good quality tapes.

I still use DAT - primarily because what you feed in is -exactly- what you get out (via SP-DIF) and it provides subcode, including time and date stamping - which is great for archiving - esp. considering that the result is a little tape you store away in a metal box.

I have DAT tapes which are 20 years old now and they still play with near zero bit errors.

My suggestions are:

Only buy direct drive machines
Only buy low hour machines
Only use good quality tapes
NEVER use data tapes - they are far too abrasive for the heads on an audio machine.

[garranimal]

I was using a Panasonic DAT in the late 90s for recording analog audio input. I forget which model. The Analog/Digital converters sounded amazing.

[madtheory]

Anything tape based is a pain in the bum compared to hard disc with multiple DVD/ CD backups. Particularly for archiving. DAT is also limited to 16 bit unless you have one of the now rare TASCAM machines.

Ya, the Panasonic converters sounded good, but are easily surpassed by any basic modern audio interface. The brightness was a good companion to the dullness of the half inch Tascam 8 track

Yes, a good DAT machine is a wonderful piece of engineering. Not at all wonderful when you need it serviced though.

IMHO, a museum piece.

[HideawayStudio]

Anything tape based is a pain in the bum compared to hard disc with multiple DVD/ CD backups.

Yes but please bare in mind that writable DVD (especially RW media) is NOT a media chosen by professionals for archival backup - it simply isn't stable enough over time. Good quality CD-R is better but, as you suggest, multiple copies should be made. I have lost both CD-R and writable DVD based backups over the years. Some of the most stable technologies are magneto optical - the now ancient MO disks were the choice of archival, media and medical centres for many years due to their excellent data retention which surpasses many modern technologies in this respect. It might surpise some to note that this includes MiniDiscs - the media (but sadly not the players) is extremely stable over time but sadly they store compressed audio and hence not very useful for these purposes.

DAT is tape based but it's known for having a very high data redundancy in audio applications which means it will tolerate some bit errors before corruption/dropouts occur.

[Stab Frenzy]

Moving parts = Headaches.

[Esus]

Moving parts = Headaches.

Microscopic moving parts=Extreme Headaches.

Keep in mind, however, that a magnetic platter spinning at 5400 to 10K rpms over long periods of time, writing and reading a dye-based substrate of varying microns of thickness isn't exactly an optimal situation either...

To paraphrase the Old Sage:
"In the digital realm, if you're only going to save your data in one format, you might as well not save it at all".

[Stab Frenzy]

Moving parts = Headaches.

Microscopic moving parts=Extreme Headaches.

Keep in mind, however, that a magnetic platter spinning at 5400 to 10K rpms over long periods of time, writing and reading a dye-based substrate of varying microns of thickness isn't exactly an optimal situation either...

To paraphrase the Old Sage:
"In the digital realm, if you're only going to save your data in one format, you might as well not save it at all".

That's very true, but you don't see people using 10 year old HDs still like you do with 10-15 year old DATs. Also HDs are a sealed whereas DATs can get dust and grit in their mechanisms.

[FX23]

heres what i found out about mine -



Technics SV-DA10
(1990 - 1994+)

Probably the most sturdy, reliable and indestructible D.A.T. mechanism ever -
> the RAA-1001 mechanism will never let you down. <

The SV-DA10 was the consumer version of Panasonic's SV-3200 professional deck ; the same mechanism was used for the later SV-3700, SV-3800, SV-3900, SV-4100 followers as well as in the SV-E10 down-sized version of the DA10 and in the Japan-only SV-D900 upgraded version. It was also chosen by STUDER for its own DAT recorders - case in point! All of these sported Technics' trademark dual 1Bit MASH with 64x oversampling digital stages, the very practical shuttle search and incredibly fast FF/REW... 400x speed! Scary but completely safe

Sold in black (less) or gold (more) between 1990 and 1994, with a few tweaks readily available to upgrade the i/o stages and headphones plug. AFAIK, the DA10 was the only consumer D.A.T. recorder allowing to add ABS-time after the recording! Cassettes-wise, the best match I have found are the Maxell Pro - vanishingly low error rates, even after many rec/play cycles.

[madtheory]

Yes but please bare in mind that writable DVD (especially RW media) is NOT a media chosen by professionals for archival backup

That's misinformation. Surf over to Brad Blackwood's or Glenn Meadows's mastering forums. DVD backup is the current norm, make several copies for redundancy. Takes up less space and can be automatically catalogued electronically. HDs are not reliable for long periods, especially when left idle. Taiyo Yuden make the best optical media, 20+ years. An archive has to be maintained.

There are some posts by George Massenburg from a while back with a comparison of archiving formats achieved with destuctive testing at several institutions. DAT was the least reliable tape because it is the "metal" formulation. You mentioned U Matic tape stripping- DAT tape is the same formulation!

You're wrong about the Sony PCM F1 format too. Greater tape area, so less chance of dropout compared to DAT. This format actually outlived DAT, as the standard for glass mastering of CDs.

Historical sound archives use 7.5 ips ferric oxide tape (a proven format) and CD/ DVD for backup.

DAT is a 16 bit DODO. Get out your S/Pdif cable and backup those tapes now while they still play.

Vintage synths are worth the trouble, but not vintage digital tape!

[Esus]

That's the best advice I've seen yet on this thread.

Every DAT tape I care about has been transferred to CD-R and DVD-R. Better chance of survival.
I've also had much better luck backing up finished tracks as .wav rather than .cda. No problems yet with accessing a Wave file, but I've lost more than a few things with CD Audio media.

BTW, if anyone's interested, here's what the recording industry's recommendation for delivery and archiving are:

http://www.grammy.com/PDFs/Recording_Ac ... ryRecs.pdf

Subject to change, of course...

If it hasn't been done recently, maybe a thread about backup/archiving media here? Tips, Tales, & Tragedies?

[FX23]

so 44.1khz pcm wavs are good for masters and archiving?

i used to think my dat at 48khz sounded fantastic!

[Esus]

so 44.1khz pcm wavs are good for masters and archiving?

i used to think my dat at 48khz sounded fantastic!

48K works primarily because it's more of an equal multiple (48, 96, 192, etc), and you don't need to gearbox it to a funky sample rate like 44.1 (for Audio CD) or 88.2 (for ???-just because?). Audio for film and video never specs 44.1, always 48KHz minimum--that industry had a little more time to let the dust settle and make more logical decisions. IMO, the Red Book standard for Audio CDs was a pretty rushed affair. I think 44.1 was settled upon because 22KHz was referenced as the top end of human hearing; the logic at the time was, doubling that number would eliminate any potential aliasing and other artifacting with the filters available at the time.

I have CD-Rs with wave files that are 10 years old, and haven't had any problems with retrieval. I've had a failure rate of about 40% with the same vintage CD-Rs that contain CDAudio (.cda) files. So wave files have worked for me. I keep non-video based audio projects at 44.1, because the chances are good that they'll end up on a CD anyway, so that would keep things simpler. Sample rate conversion has improved a lot over the last 10 years or so, so I may decide to go higher. But why stop @ 48? 24/96 seems to be the best of all worlds, and blank media is pretty damn cheap these days.

[madtheory]

WAV is better because data formats have much more robust error correction than cda. There is also the problem that hardly any computer based optical drives implement Reed Solomon error correction. So sometimes you'll have a cda disc that will play in a CD player, but won't rip.

48K works primarily because it's more of an equal multiple (48, 96, 192, etc),

That was a problem 15 years ago, but not now. You just multiply away up until you get an equal multiple, then do your resampling.

48kHz sounds better because the cutoff is a little higher, so again the ringing is harder to hear. We ended up with 44.1kHz and 48kHz because of mechanical limitations in the Sony video tape decks. Prior to that, 50kHz was more common with open reel digital formats. That would have given us a better balance- easier to make a steep filter that didn't ring audibly, and a reasonable data size.

But a good converter design can completely eliminate ringing at pretty much any sample rate, these days.

[HideawayStudio]

Yes but please bare in mind that writable DVD (especially RW media) is NOT a media chosen by professionals for archival backup

That's misinformation. Surf over to Brad Blackwood's or Glenn Meadows's mastering forums. DVD backup is the current norm, make several copies for redundancy. Takes up less space and can be automatically catalogued electronically. HDs are not reliable for long periods, especially when left idle. Taiyo Yuden make the best optical media, 20+ years. An archive has to be maintained.

There are some posts by George Massenburg from a while back with a comparison of archiving formats achieved with destuctive testing at several institutions. DAT was the least reliable tape because it is the "metal" formulation. You mentioned U Matic tape stripping- DAT tape is the same formulation!

You're wrong about the Sony PCM F1 format too. Greater tape area, so less chance of dropout compared to DAT. This format actually outlived DAT, as the standard for glass mastering of CDs.

Historical sound archives use 7.5 ips ferric oxide tape (a proven format) and CD/ DVD for backup.

DAT is a 16 bit DODO. Get out your S/Pdif cable and backup those tapes now while they still play.

Vintage synths are worth the trouble, but not vintage digital tape!

OK - I think I need to clarify my stance on this - I broadly agree with you.... I don't use DAT anymore for mastering and transferred them to a mixture of multiple CD backups and two bullet proof professional 6 disk SCSI SCA RAID arrays running on Sun Sparc stations. I was mearly trying to stand up for a well designed standard that is misunderstood by many.

Your comment about u-Matic tapes being the same formulation is sadly not quite correct. It is true they are very similar in nature, but the problem with many of the u-Matic tapes of the era was that the tape binding layer turned out to be unstable with age and was pretty much unique to the u-Matic format. I have never heard of this anomaly happening to anything like the same degree with audio DAT. DAT may be 16 bit only but it is at least phase coherent, quit unlike PCM-F1 (which I used to use), and suffers from a stereo delay due to the way the channels are interleaved and not properly time aligned - at least it's not compensated for on some of the SONY PCM series anyway. I used to use the F1 format with Sony Betamax which was by far the best helical scan video system for use with F1 in my opinion (although I did use u-Matic for a number of years before that).

As for DVDs being ok with age we will have to agree to disagree. I have friends and colleagues who have had horror stories with long term writeable DVD use. On many archival sites the same warnings are made. That said - I don't trust many modern formats - especially modern hard drives who's data densities are now so high it's a wonder they work at all.

Don't forget - if your analog tape, DAT tape or F1 master developed dropouts/errors - at least some of it was rescuable. If your DVD or CD master fails the chances are it's ruined.

As others, and yourself have suggested - I totally agree that the best way simply has to be multiple backups on a variety of digital formats.