Tom:
While DAT wasn't lossy per se (at least in the recorded bitstream), the
reality was that, depending on the tape and the machine, there could be
a significant amount of error concealment taking place (or worse issues).
I ate a lot of crow once when I foolishly used DAT on a day of pickup
work on a picture, only to find that there was a problem with the tape
when they tried to play it in post. We never did determine whether it
was the tape or the machine that was at fault, but it wasn't pretty...
When using DAT for production work, we had more than a few occasions
where there were problems with either the tape, or the shell, (or both)
which would cause severe issues when trying to reproduce them. My guess
is that I've probably re-shelled at least a dozen tapes during that
period to make them playable (and this was using high-end Sony 7000
series machines).
All in all, I'm glad to see 'em go. Now, how about the Sony F1 format?!
--Scott
Tom Fine wrote:
> Hi Scott:
>
> My take on DAT is, transfer what you got and be out of the format. But
> in its time, it wasn't lossy and it even offered (slightly) better
> resolution than a CD master. Also, Sony had "Super Bit Mapping"
> (20-bit A-D conversion down-converted to 16-bit storage) available
> even on lower-end machines.
>
> All in all, sound quality wise, DAT was superior to MD and other
> lossy-encoded media.
>
> I bet most of us here would have killed for one of these little $300
> flash recorders when we bought our first $1000+ DAT recorder. You
> sound-for-picture guys would have mass-killed for one of these
> high-end many-tracks flash recorders.
>
> -- Tom Fine
>
> ----- Original Message ----- From: "Scott D. Smith"
> <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Thursday, January 21, 2010 7:22 PM
> Subject: Re: [ARSCLIST] DAT ripping
>
>
> As Tom nicely points out in his summary of the life of the DAT, it
> indeed was never meant to be a professional format.
>
> After Sony realized their misstep in the market, they hurriedly tried
> to figure out how to re-coup their development costs. The thinking
> being: Hey-if consumers won't use it, maybe we can dump it on the pros!
>
> Subsequent to my experience using DAT recorders to record sync sound
> for a feature film ("The Package")in 1988, I sat on a panel discussion
> at the New York AES show, discussing the pros and cons of the format
> for pro use.
>
> At that meeting, I distinctly recall pointing out the numerous
> shortfalls of the format for pro users, and was nearly booed off the
> stage by a contingent who thought it was the greatest thing to come
> around since the introduction of the CD. Hey, perfect sound, right?
>
> Funny-I haven't really heard too much from that crowd lately...
>
> --Scott D. Smith
>
> Chicago Audio Works, Inc.
>
> Quoting Tom Fine <[log in to unmask]>:
>
>> When DAT first came out, the original press on it was "here's a
>> cassette-like home medium for the digital age." But the copy-protection
>> scheme made it impossible to use it as many people were using cassettes
>> at that point (tape-to-tape copies), duplication of DATs was a costly
>> endeavor since they can't be run off on a mass-duper like cassettes.
>> Remember that at that time period -- the Walkman era -- cassettes were
>> the primary mass medium for music in the US, having passed LP numbers
>> in the late 80's. So a cassette replacement needed to have a major
>> pre-recorded component. The record companies had invested or were
>> investing billions in CD plants, that's what they wanted to be the
>> _ONLY_ consumer mass-medium. So it was another case of clever hardware
>> engineering for a market that wouldn't buy in quantity. BUT, DAT was
>> immediately and enthusiastically embraced by the portable-recording
>> market, specifically higher-end radio recording, recording of events at
>> colleges and other venues, and the Grateful Dead taping army, among
>> other audiences. So, quickly, quantities of recorded DAT tapes started
>> piling up in various organized and non-organized archives. Also at that
>> time, recording-industry people realized DAT was a good way to make a
>> listening/proof copy off the same digital buss feeding the
>> U-Matic-based mastering system. After all, any producer or record
>> company exec could have a DAT machine in their home or office, but few
>> to none could have a 1630 playback system. So more DAT tapes started
>> piling up. Then, lower-end studios and self-recording folks adopted DAT
>> due to convenience and cost. Many more small studios than we'd like to
>> think were mastering to DAT throughout the 90's and even into this
>> decade. Also the commercial/industrial sound production business. And
>> sound-for-picture.
>>
>> So, yes, never intended for the professional uses which became its
>> market.
>>
>> -- Tom Fine
>>
>> ----- Original Message ----- From: "Ted Kendall"
>> <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Thursday, January 21, 2010 6:05 AM
>> Subject: Re: [ARSCLIST] DAT ripping
>>
>>
>>> As far as I know, DAT was never intended as a professional medium
>>> at all, but a domestic one. The anti-copying furore in the US which
>>> led to SCMS scuppered that, so the Japanese had to sell it as an
>>> F1 replacement.
>>>
>>> Agreed, though - those first generation machines can be very
>>> tolerant of marginal tapes. Whether this is a mechanical thing or
>>> more generous interpolation, I wouldn't know. I also harbour
>>> memories of a particular DAT which refused to play at all on any
>>> machine except a Fostex D20 - and that had the error light
>>> continuously on! The audio, however, was quite OK.
>>>
>>>
>>> ----- Original Message ----- From: "Paul G Turney"
>>> <[log in to unmask]>
>>> To: <[log in to unmask]>
>>> Sent: Thursday, January 21, 2010 9:18 AM
>>> Subject: Re: [ARSCLIST] DAT ripping
>>>
>>>
>>> Further to this, you will find that some mechanisms perform better
>>> than others, the PCM 2500 for example will play tapes that the 7000
>>> series won't.
>>> And often more plays will yeild a better file, but DAT was always
>>> meant to be an editing medium, not long term storage.
>>>
>>> Paul Turney
>>> Sirensound Digital Audio
>>>
>>>
>>> -----Original Message-----
>>> From: Shai Drori [mailto:[log in to unmask]]
>>> Sent: Thursday, January 21, 2010 09:14 AM
>>> To: [log in to unmask]
>>> Subject: Re: [ARSCLIST] DAT ripping
>>>
>>> Okay, that I understand, but I am thinking about correctable
>>> errors. We are then assuming that both systems will correct the
>>> errors the same way since both use the schemes implemented. How do
>>> we know which system has fewer errors over the other? My experience
>>> with rotary head systems is that sometimes second or third reading
>>> yielded better results, I think due to "cleaning" actions of the
>>> previous playing. Maybe we should compare five readings of the same
>>> cassette?ShaiTed Kendall wrote:> In my view, yes.>> Consider - you
>>> have two data files. One is a text document (for the > sake of
>>> argument). The other is a digital audio file. Both have errors >
>>> in the storage medium. This is inevitable, so we devise error >
>>> correction strategies (redundancy, check codes, etc). These allow
>>> us > to correct errors completely and accurately.>> Suppose now
>>> that there is an error in the storage medium which is too > large
>>> to be corrected. This will cause an obvious error in the text >
>>> file, which is unaceptable, so the system does not allow for it and
>>> > declares the file corrupt. The audio file, however, can be
>>> rendered > inoffensive by interpolation, and this is implemented in
>>> the DAT audio > format. If we retrieve DAT audio in a system which
>>> does not admit of > interpolation, we therefore know that the data
>>> are accurate, as any > uncorrectable errors are recorded as
>>> such.>>>> ----- Original Message ----- From: "Shai Drori" > To: >
>>> Sent: Thursday, January 21, 2010 7:37 AM> Subject: Re: [ARSCLIST]
>>> DAT ripping>>>> My own experience with dat is that almost all tapes
>>> have some form of >> errors on them. I think the idea in dds is
>>> that errors are better >> fixed than dat machines. There were many
>>> machines that came off >> assembly lines not at spec, thus making
>>> the tape not a standard tape. >> Some machines are better at coping
>>> with these (my experience with >> Sony is better than tascam for
>>> example, but I suspect this is highly >> subjective). All in all,
>>> I think the DAT format was the word digital >> format I have ever
>>> come across.>> Also' checking two files one against the other will
>>> not necessarily >> prove one format better than the other. If you
>>> get some audio, how >> can you be sure one stream is correct and
>>> the other is corrupt? >> Either the dat or dds stream could be
>>> better, or am I missing >> something in the methodology?>> Shai>>>>
>>> Tom Fine wrote:>>> I'm happy to do a SPDIF to hard drive transfer
>>> and then exchange
>>>>>> tapes with someone using a PC-drive transfer system so we can do
>>>>>> the >>>
>>> comparison Richard mentions.>>>>>> Please ping me off-list if you
>>> have a working PC-drive transfer >>> chain and want to exchange
>>> DATs and computer files.>>>>>> -- Tom Fine>>>>>> ----- Original
>>> Message ----- From: "Richard L. Hess" >>> >>> To: >>> Sent:
>>> Wednesday, January 20, 2010 5:14 PM>>> Subject: Re: [ARSCLIST] DAT
>>> ripping>>>>>>>>>> Hi, Tom,>>>>>>>> After I saw your post and
>>> re-read Jim's post, I think I understand >>>> where he is coming
>>> from.>>>>>>>> What we _should_ be able to do is take the DDS ripped
>>> file and an >>>> AES/SPDIF'd copy of the DAT from an audio DAT
>>> machine, align the >>>> starts, invert the phase of one, and get
>>> dither or silence.>>>>>>>> In both instances, we're pulling numbers
>>> off the tapes (although >>>> the basest representation of the
>>> numbers is analog on the tape, the >>>> processing in both instances
>>> interprets these analog signals as >>>> either ones or
>>> zeros).>>>>>>>> I would not, without doing the tests that Jim is
>>> talking about, be >>>> 100.0000% confident that the two files are
>>> identical.>>>>>>>> I think that the DDS reading could be "better"
>>> than the audio DAT >>>> reading as there is no error concealment
>>> stage in a data recorder, >>>> so if you grabbed all the bits via
>>> the DDS route, you could be sure >>>> that they were
>>> correct.>>>>>>>> These are all subtle differences and are probably
>>> not as large as >>>> the "Interstitial Errors" that Chris Lacinak
>>> is talking about here:>>>>
>>> http://www.avpreserve.com/wp-content/uploads/2010/01/Digital_Audio_Interstitial_Errors.pdf
>>>
>>>>>>>>>>>>>>> I would expect some burst differences between the two
>>>>>>>>>>>>>>> methods,
>>> and >>>> those bursts would be where the audio DAT's error concealment
>>>>>>> kicked in. Other than that, they should be identical, presuming
>>> you >>>> haven't introduced an interstitial error in one copy or
>>> the other.>>>>>>>> I'm glad to see Chris offering to help. I am
>>> interested in this. I >>>> would also like to know who is set up
>>> with the DDS Mass Ingest of >>>> DATs as I am sometimes asked who
>>> can do large DAT collections. At >>>> the moment, I am not
>>> interested in doing any because of anticipated >>>> remaining
>>> headlife on my machines, the growing lack of parts for >>>> DAT
>>> machines, the need to transfer my own DAT collection first, and
>>> >>>> the analog work that I have piling up.>>>>>>>> Cheers,>>>>>>>>
>>> Richard>>>>>>>> At 04:27 PM 2010-01-20, Tom Fine wrote:>>>>> Hi
>>> Jim:>>>>>>>>>> How could the data be "better" than a direct-digital
>>> out from a >>>>> properly-working player (ie no head problems or
>>> mechanical >>>>> issues)? I thought the main advantage of the
>>> computer-drive method >>>>> was to save time. Is there more to
>>> it?>>>>>>>>>> -- Tom Fine>>>>>>>>>> ----- Original Message -----
>>> From: "Jim Sam" >>>>> To: >>>>> Sent: Wednesday, January 20, 2010
>>> 12:45 PM>>>>> Subject: Re: [ARSCLIST] DAT ripping>>>>>>>>>>>>>>>>
>>> All,>>>>>>>>>>>> First, Dave, that information is very
>>> helpful.>>>>>>>>>>>> That said, I didn't ask because I'm worried
>>> about the theory. I >>>>>> was asking>>>>>> for a collaborator in
>>> testing.>>>>>>>>>>>> The theory's been discussed before on this
>>> list, and I'm aware >>>>>> that more>>>>>> than one
>>> person/organization has experimented with this to some >>>>>>
>>> success. It>>>>>> was also *briefly *discussed at last year's
>>> conference in DC.
>>>>>>>>> However,>>>>>> every time I've seen a discussion about the
>>> topic, it has never >>>>>> come along>>>>>> with what matters to
>>> me: testing to make sure what's coming off
>>>>>>>>> the DDS>>>>>> drive is the same (or better) data than what
>>>>>>>>> would go
>>> down the >>>>>> AES/EBU>>>>>> pipeline.>>>>>>>>>>>> I'm still
>>> extremely interested in this situation, and after >>>>>> having had
>>> to>>>>>> deal with other similar formats, I've got ideas for
>>> testing that >>>>>> I'd like to>>>>>> do. But I don't have a
>>> working DDS setup here. I could build my
>>>>>>>>> own, which>>>>>> I might do, but that's a can of worms, and
>>>>>>>>> there's
>>> other things >>>>>> to be gained>>>>>> by having a collaborator in
>>> these tests.>>>>>>>>>>>> Thanks,>>>>>> Jim>>>>>>>>>> Richard L.
>>> Hess email: [log in to unmask]>>>>> Aurora, Ontario, Canada
>>> (905) 713 6733 1-877-TAPE-FIX>>>>> Detailed contact information:
>>> >>>>> http://www.richardhess.com/tape/contact.htm>>>>> Quality tape
>>> transfers -- even from hard-to-play tapes.>>>>>>>>>>
>>>
>
