Conference napalm::commusic_v1

    PRECISION ON .0 :
    
    Performer lets combine sounds, compose music, and it stores layers
    (tracks), up to 24. It looks like a tape recorder. What if you want
    to record vocals ? You sure would need an A/D converter. If it's
    that simple, why don't they make one ?
    
    Argh, maybe I'm real stupid, there must be some reason...
    

    Programs like Performer, and other MIDI sequencers, record MIDI
    data, not a digital representation of the sound waves.  To play
    from a MIDI sequencer you need a MIDI instrument to convert the
    gestural information that MIDI represents into sound.  (Of course,
    you can have a simulation of such an instrument within the computer.)
    
    The problem with a computer-based recorder that really records sounds
    is the quantity of data.  MIDI requires about 8 bytes per note,
    whereas a good digital representation of sound requires about
    176,400 bytes per second.  (That's assuming 16 bits per sample,
    44,100 samples per second, two channels.)
    
    A Compact Disk is just such a digital recorder.  The technology
    that made it possible was the ability to impress lots of bits onto
    a disk.  A 90-minute song requires about 952,560,000 bytes.
        John Sauter

                    
    
    I notice that Synclavier was showing a system a few months back
    that could link up to 16 channels of digitized audio up with 32
    channels of sequenced MIDI data so you *could* use your Synclavier
    as a tapeless audio recorder. Basically, it's just sampling with
    unlimited sample length.
    
    You needed a Winchester and some other stuff.....knowing those guys,
    it probably is *very* expensive.  I don't know if they are actually
    shipping these things yet, because at the show they only had *4*
    channels of audio on the prototype.
                                  
    Their ads championed a system whereby you record everything at home,
    then you drag your keyboard and Winchester down to the Record Plant
    and go digital right to the CD master.....
                             
    
    
    

    
    Re: -1
    
    The system is called Direct-to-Disk and it will record up to three
    hours of music on 16 tracks. Must be megabux.
    
    CdH
    

Lexicon has a similar 32 channel system that goes direct to disk.  It also
keeps track of slider movement, etc.  Supports SMPTE, etc.

It is megabucks.

Todd.

    We're talking gigabytes of storage here, folks.  Gigabytes of high
    speed storage (or a storage hierarchy that allows conversion at
    audio rates) that's also writeable still costs lotsabucks.  (Lotsa-
    is the next prefix after tera- ?).
    
    len.
    

< Note 932.0 by PRSTRA::CHAMPOLLION >

>    I heard somewhere that Casio will be selling a 4-track digital
>    recording machine, DAT technology on four simultaneous tracks.
>    Confirm ?

I haven't heard anything about the Casio, but the latest 
Electronic Musician magazine has an article about DAT recorders.  
They claim that there will be several modes of operation for 
DAT's (one is 4-track), and not all DAT's will be able to use all
modes.  While the normal stereo mode will sample @ 48K Hz., the
4-track mode will sample @ 32K Hz. so will only give a max 
frequency response of about 15K Hz.  

John

    There is a tape-less recorder for the MAC, but it comes in a separate
    box.  It is two-track and costs (I think) $3000 without winchester
    drives.  Add two Maxtors (~150 Meg) at $2000 each and a MAC+ at $2000,
    and you have 28 minutes of stereo, digital recording for the tune of
    $9000. 
    
    I think a Tascam 38 provides much more flexibility for less money at
    about the same weight.  [If I had one] I wouldn't give mine up for
    anything...
    
    Steph

    I saw a brief note (in the back of MIX, I think) about a modular
    digital multitrack recording system.  The idea was to provide two
    tracks per module, using cassette (or DAT) technology.  Using either
    an extra track or the DAT supported additional data (DAT stores
    a lot of data besides just the encoded audio) you could lock multiple
    transports together to get as many tracks as you wanted.  It's not
    unreasonable to expect DAT decks to come down to the $500 ballpark,
    so you could have 8 tracks of digital audio for about $2000, which
    is competitive with 8 track analog.  Better, this digital recorder
    would handle 90 minutes, whereas a 2400' reel at 15 ips is only
    good for 32 minutes.  Add the fact that the tape is addressable
    (i.e., you can tell the transport(s) "go to song 3") and you've
    got a pretty competitive offering.  The system is expandable (you
    don't have to buy all 8 tracks at the same time), and being digital
    there is no loss of quality when pingponging.

    You'd have to use multiple tapes, but DATs are smaller than cassettes,
    and I'm sure some entrepreneur will come up with some kind of cute
    little multitape storage case/carrier.
      
    Cassette decks typically take up 3 rack spaces, but you could probably
    squeeze a DAT deck into 2, so an 8 track machine would require 8
    rack spaces, less than a Tascam 38 takes.  A 16 track unit would use
    16 rack spaces, still not outrageous.
    
    A nice side effect of this approach is you only need one kind of
    tape - your two track medium and 8 track medium are exactly the
    same!  Furthermore, you can use the same deck for both purposes!  
    It's not clear what blank DATs are going to cost, but even
    by the case 2400' of 1/2" tape is about $22, so if blank DATs can
    be had for $5.50 each you get 3 times the recording time for the
    same price.
    
    For this I would give up my 38!
    
    len.
                                                 

    Check the interview with Kim Ryrie (Mr. Fairlight) in last month's
    Music Technology.  He talks about direct-to-disk systems, DAT and
    WORM disks, etc.  He isn't really happy with any present technology.
    
    						-Jeff
    

I seem to recall that the 8mm video tape format uses digital recording
for its audio track.  It is only 8 bits (nonlinear), but I hear it is
not awful.  In any case, if you do not record video at all, some decks
can record 8 tracks of audio instead.   I think Sony makes a deck that
does this.

    < Note 932.6 by DRUMS::FEHSKENS >

>    We're talking gigabytes of storage here, folks.  Gigabytes of high
>    speed storage (or a storage hierarchy that allows conversion at

    Not necessarily. Two VCR's will perform this function quite admirably.
    
    	88000 bytes/(second*track) (16 bit resolution)
        32 tracks
    
    	approx. 270000 bytes/second (astronomer's mathematics :-) )
    	which is about 1.7 megabits/sec. Not really that bad. Even 
    	Ethernet is that fast.
    
    	Since in general we want to access this data sequentially, why
    	bother with a disk drive (they ain't cheap.)
    				- HBM       

    re .12 - exactly.  I was assuming from context that we were talking
    about random access storage.  In a subsequent reply I mentioned
    the use of stacked DATs, which are essentially VCRs.
    
    len.
    

    re .12 again - I hope most astronomers are better with exponents.
    
    You're short a factor of 10.
    
    32 * 88000 = 2,816,000.
    
    len.
    

    
    Oops! You're right!
    
    That makes for approx 17 mbits/sec (which _is_ faster than Ethernet)
    but not faster than SCSI (at 5 mbytes/sec). It can still be handled
    by a VCR...
    				- HBM

The Sept. 14th issue of ADWEEK has a Fall Preview, with
a special report on Home Electronics.  After talking about
all the difficulties of getting DATs accepted in the U.S.
because of the copyright issues,  the article concluded
with the following paragraph:
	The issue is further complicated by the
	industry's decision to police itself before
	the legislation was proposed.  Japanese manu-
	facturers, leery of backlash when DAT was
	invented, added a step in the recording pro-
	cess that technically makes a perfect master
	copy impossible.  When a CD signal is sent into
	the DAT recorder, it is converted to an analog
	signal and then back to digital.  While this does
	not noticeably reduce the fidelity, suppliers
	claim it does shoot down the copyright objection.

Now, I don't know if a DAT recorder can distinguish between a CD
signal and other types of signals, but this is the first I've ever
heard that the DAT recorders are actually doing a D/A then A/D 
conversion internally!

Is this true?

/chuck

    Only sort of true.
    
    DAT recorders are capable of recording at three different sampling
    rates (~38, ~41, and ~48KHZ?).  CD's are recorded at 41KHz.
    
    The story filtered through my memory is that they will record from
    the analog inputs at any of the three (presumably selectable) rates,
    but will only record at 38 and 48KHz via the digital port.
    
    To record a CD, you must use the analog output of your CD into the
    analog input of the DAT.  Since (very) few CD's have digital outputs
    anyway, I doubt this has the same flame potential as copyguard.
    
    Which brings up another question.  What (existing) formats use
    the 38 and 48KHz rates?  They must intend to use the digital port
    for SOMETHING.

    Dave

>Which brings up another question.  What (existing) formats use
>the 38 and 48KHz rates?  They must intend to use the digital port
>for SOMETHING.
     ^^^^^^^^^
    
    Yo, Dave ! Other DAT units !!!!! .. if Nyquist was right, giving
    19KHz and 24Khz response, respectively... opens up a whole new
    world in me giving you a master-quality copy of MY ORIGINAL music.
    
    karl moeller

    Re .19
    
    DAT units can understand each other's bits and bytes.  That's cool.
    
    I assume the 41KHz rate is there to allow record companies to use
    their existing CD master 'tapes' and equipment to generate pre-recorded
    DAT tapes.

    But are there other devices that talk at 38 or 48 KHz?  What's the
    sampling standard for studio digital recorders -- 48?  Or the PCM
    adapters for VCR's?  Are these numbers magic or were they chosen
    for compatibility?
    
    Dave