Conference napalm::commusic_v1

    I wonder if they're the sync tones for the tape copiers? Musicassettes
    often have 'thud thud thud' noises at the end (the result of high-speed
    bleeps replayed at 1 7/8), so perhaps ECM's natural speed copiers
    produce natural frequency bleeps?
    
    Richard.

	I've noticed the same thing on a number of my newer tapes.  I'd be 
interested in any inside scoop as well.

	Dan

    I have it on a Carla Bley tape, also an ECM...
    
    Maybe it's designed to melt down your deck if you try to copy it....
    or better yet to send signals to the PRMC that you listen to
    *unacceptable* music......

    Here's the scoop from Dr. Duplication:
    
    Commercially dubbed cassettes are done various ways, in the shell
    (slow, espesivo) and 'pancakes'.. the pancakes are actually the
    1/8" tape, recorded on all four tracks at once, but many thousand
    of feet long.. i.e. many many cassettes' worth of music, end-to-end.
    
    Then the pancake is mounted into an automatic shell loading machine.
    This pulls half a cassette shell in, reels off one cassette's worth
    of tape, terminates it, and mounts the top half of the shell.
    
    Now, older loaders used a 6 cycle per second tone to delineate the
    tape sections.. check it out, some of your commercial cassettes
    will have a low rumble at the beginning.. these days the ascending
    tones perform the same function, separating the copies from one
    another on the 'pancake'.
    
    karl moeller

    
    I thought they copied tapes *backwards* so that there were
    fewer (if any!) transients. This means duping at very fast
    speeds. 

    have I been duped?
    

    Never heard that tapes were duped backwards.. but you're right,
    it would nearly eliminate hard transients.. the tones we're discussing
    would also work backwards, I suppose.
    
    k_the_intern

    Wait a minute guys - are you trying to tell me that acceleration
    kills but deceleration doesn't?  And edge is an edge, whether it's
    rising or falling.  You want to explain to me how the frequency
    content of a signal changes depending on what direction you scan
    it?
    
    len.
    

    uhh.. far be it from me to argue with a Software Engineer Person..
    and please remember it wasn't me who said that commercial dubbing
    was done backwards..
    
    As a person who has recorded really intense piano whacks, then played
    them backwards, I recall the backwards tone smoothly building up
    to... silence !  And this 'smooth buildup' fooled me into believing
    that duping a tape backwards (not MY idea) might minimize 
    leading-edge-transient distortion and maximize tape headroom..
    
    no way, huh ?
    
    karl
    

    Uh, no way that I can see.  And my response was not meant ad hominem
    but rather to the conference in general (my apologies to the female
    "guys" out there).
    
    And to properly (dis)establish my "credentials", I am no longer really
    a Software Engineer Person (the only code I write these days is
    Amiga Basic to generate weird graphics); I've "progressed" to the
    smoke and mirrors realm of architectural strategy.
    
    Like I said, an edge is an edge, rising or falling.
    
    len.
    

    OH. You're a 'concepts' guy. Me too. (can't DO anything, but know
    ABOUT a lot of things)
    
    Did YOU put the 'rat' in 'CIM StRATegy' ? 
    
    karl (where's KMI these days? packing for Europe? miffed? what?)