Conference hips::uk_audioo

    Digital Audio Cassette (Or DAC I think) is a new form of digital from
    Phillips.
    
    It uses standard Compact Cassettes (Tapes to you and I) but records its
    infomation digitaly.
    
    Does anyone have any more infomation.
    
    	Type of head (helical, linier)
    	Sampling Freq. + No. of bits. eg 48K @ 16-bit
    	Availability
    	Type of tape required (Metal or Chrome or what)
    	Expected Cost of Machines (+ tapes if special required)
    	Recording time (C45, 60, 120, 180...)
    
    	Is DAT still born ?

      re...   <<< Note 249.1 by CHEST::WATSON "Back to mono" >>>
                               -< Info required >-

    >>Digital Audio Cassette (Or DAC I think) is a new form of digital from
    >>Phillips.
    
    >>Does anyone have any more infomation.
    
    	>>Type of head (helical, linier)
    
    	Thin film, linear
    
    	>>Sampling Freq. + No. of bits. eg 48K @ 16-bit
    
    	Not sure, but I recall something around 32kHz
    
    	>>Availability
    
    	Nothing, not even a prototype. Philips have some of the ideas
    working on a bench, but that's all. It's mostly vapourware.
    
    	>>Type of tape required (Metal or Chrome or what)
    
    	The tape proposed is a special formulation, encased in videotape
    type box (but cassette-sized). Players are proposed to accept tapes
    of the analogue variety we all know and love, but only for replay.
    
    	>>Expected Cost of Machines (+ tapes if special required)
    
    	Nowhere near knowing yet.
    
    	>>Recording time (C45, 60, 120, 180...)
    
    	As above
    
       	>>Is DAT still born ?
    
    	I assume you mean still-born, i.e. born dead. Many would like it to
    be, especially the music industry, who have given preliminary backing
    to Digital Audio Cassette. Personally I see this as a delaying tactic,
    designed to move the industry's focus away from DAT, as I cannot see
    why someone doing digital copies on DAC is any less objectionable to
    doing it on DAT. The IFPI's backing of DAC, which doesn't exist, is an
    indication to me that they are trying move the major labels' focus away
    from DAT for a little while longer, to maximise CD sales before CD
    becomes pass�. The �550 Sony DAT machine is selling like hot cakes;
    this and the report in HFN/RR that Philips are buying in some DAT
    machines, possibly to fit their own ADC/DACs then rebadge, says it all
    about Digital Cassette to me.

	Phillips seem to be mounting a DAT 'spoiling' operation by whispering 
about DAC. They have promised a prototype is to be demoed at some HiFi show in 
about 6 months with consumer products in 1992.

	To my mind it's a retrograde step to try and attempt to use compact 
cassettes as a digital medium. They will not be helical scan technology but
will apparently mechanically operate in just the same way as the current
cassette machines. The DAT tapes are more robust than cassette and generally
benefit from being designed 20 years later than compact cassettes. One of the
beauties of DAT is that the tapes are physically small and the tape lengths
short. This means that finding individual tracks takes only seconds. 

Nigel

    I think the DAC system may use a variable bias type noise on the tape,
    to store the sampled bit paterns.  Hmm, wonder how long such a
    recording would last?
    
    Rob.

Also, a sampling rate of 32KHz will limit DCC's (Competency Circle??) quality,
compared to DAT.

Personally, Compact Cassettes were never a high quality medium, and would
always be considered secondary (for use in the car).

However, I gather DAT's have been widely accepted by recording studios, as a
cost-effective way of doing digital recording.

I don't see the point of introducing a lower quality (potentially lower than
standard Cassette) system, when DAT looks perfectly good.

The compatibility with Compact Cassette is a red herring too. People who buy
a DCC machine will probably keep their Cassette Machine for the car.

I suspect an ulterior motive on Phillips part. They didn't have a part in
DAT, so they don't want to play.

Mark.