Re: [ARSCLIST] Some DAT questions

[Tom Fine <tflists@xxxxxxxxxxxxxxxxxxx>]

Hi Scott:

This is all very helpful. Thank you.

-- Tom Fine

----- Original Message ----- 
From: "Scott D. Smith" <lists@xxxxxxxxxxxxxxxx>
To: <ARSCLIST@xxxxxxxxxxxxxxxx>
Sent: Wednesday, January 21, 2009 1:33 PM
Subject: Re: [ARSCLIST] Some DAT questions


Tom,

A few thoughts and comments on your questions(in no particular order):

1. We experimented with a couple of different combinations of drives  
and software a few years ago in an attempt to do direct data extracts  
from DAT tapes. I would have to say that we didn't have much luck. I  
think that there would have to be a lot more work done on both the  
software and the data drives to come up with a workable solution. Not  
saying it can't be done, it's that the drives were not really intended  
to work in the fashion required for audio.

2. We have generally used professional DAT decks such as the Sony 7030  
and 7050 machines, since most of the work we do involves time code. We  
have used the AES/EBU digital outputs to feed external D/A converters  
with good success. The only issue to keep in mind with these machines  
is that they aren't very tolerant of tapes which are recorded out  
spec. There is a very tight set of tolerances that machine will accept  
as being valid, beyond which it simply will mute. There are a  
adjustments which can be made to some parts of the circuit (especially  
the servo and tracking), which will allow for a certain range of  
error, but I wouldn't go messing with these unless you thoroughly  
understand how the machine works. We routinely keep 4 different decks  
in operation, as I have found that some machines will simply not play  
certain tapes, no matter how far we try to go with tweaking. I have  
even run into incompatibilities between decks from the same  
manufacturer.

3. Because of issues with errors, I would recommend monitoring the  
tapes real-time, and keep the deck error monitoring display active.  
The pro machines also have a setting for which you can specify the  
level of errors which will result in an ERROR flag being indicated.

4. I don't see any particular reason to make an analog output copy,  
unless you want to archive in analog (some archives we have done work  
with have requested analog versions along with digital, but I think  
this is going by the wayside as the issues with digital storage are  
resolved).

5. In general, there is no compelling reason to store DAT (or any  
other digital based tape) tails out, except for the fact that the tape  
should always be exercised prior to playback. If it is tails out, it  
means it will force the user to have to rewind prior to playback. Any  
labels left in the box should be removed, but I wouldn't try to deal  
with any labels on the tape itself, unless there are starting to bleed  
significantly. Solvents such as Goo-Gone are extremely difficult to  
deal with, as they will tend to migrate over the entire shell, and  
make matters worse.

6. During the period that DAT was in regular use for production, we  
found the Sony, Maxell and BASF tapes to be generally fairly reliable.  
We did encounter problems with the Ampex tapes, mostly related to the  
shell, and also had major problems with an off-brand called "DIC/DAT".  
We had some occasional oxide shedding issues as well, which required  
cleaning of the tapes. We have also encountered tapes which were wound  
and stored with incorrect tape tension, which resulted in problems  
related to the tape geometry, which is a real horror to deal with.

In general, I have to say I'm glad to see this format go away. Back in  
the 80's, I nearly got booed off the stage at an AES seminar on the  
subject of DAT for pro use, when I pointed out to the audience that  
the format was never intended for professional use. It was only  
because it failed to find a market with the consumer that Sony, in  
their infinite wisdom, decided to try and recoup their development  
costs by trying to adapt the format for pro use.

We are now living with the consequences.

Scott D. Smith
Chicago Audio Works, Inc.


Quoting Tom Fine <tflists@xxxxxxxxxxxxxxxxxxx>:

> Hello All:
>
> I'd like to tap the collective brain (picture a non-invasive tap, like
> a Vulcan mind-meld) about DATs, with eyes to a medium-sized (several
> hundred DAT tapes, all dating from the 1990's) transfer project.
> Answers gleaned from personal experience most appreciated.
>
> 1. does anyone on-list have experience with "ripping" audio DATs
> directly to hard drive via a DAT data-tape drive? If so, what OS,
> software and results are you getting? Is there a favored source for the
> appropriate drive?
>
> 2. one key reason I was thinking for doing these DATs
> digital-to-digital would be the real-time monitoring, so I could note
> the locations of any dropouts or glitches. Assuming I'll find some, are
> there any hidden tricks or tips to fixing them or is that audio lost on
> a damaged segment of tape?
>
> 3. if done digital-to-computer, I'm assuming SPDIF, but does anyone
> have personal experience indicating either coax or optical is
> preferable? I was thinking optical, given the sometimes strange
> grounding issues of a computer.
>
> 4. is there anything to be gained by running a simultaneous
> analog-to-computer? I'm thinking, no, but I'm also thinking, I sure
> don't have all the answers so there may be something unknown to me here.
>
> 5. once a DAT has been transfered, what is the proper storage method? I
> was thinking, don't rewind it and make sure to store it in its
> protective case. I was also thinking, if there is a label-sticker sheet
> in the box, take it out since the glue sometimes gets gooey or oily
> over time.
>
> 6. finally, are there any DAT brands/types with known sticky-shed
> problems? Most of these DATs are BASF, but some are Ampex branded. I am
> not at all sure that Ampex manufactured its own DATs, they may have
> resold Japanese tape.
>
> Thanks in advance for any tips/advice gleaned from personal experiences.
>
> -- Tom Fine