You would be amazed at the number of Telex 300  Cassette duplicators banging out the  cheap n dirty  CC's.
They used in cassette duplication at  15/30 ips and  could duplicate from cassette or 1/4 inch reel masters, 2 or 4 tracks at same pass.
One company i service had 30 slaves running 16hrs/6 days week.
I would buy heads 100 at  a time from Nortronics... complete replacement every couple of  months with all the associated allignment, bias and drive adjustments  was a 2 day pain in the  toosh. 
I for one am glad this era is over, but at the time the money was good.
dnelson 


--- On Thu, 1/13/11, Michael Biel <[log in to unmask]> wrote:

> From: Michael Biel <[log in to unmask]>
> Subject: Re: [ARSCLIST] DATs DELETED but not LPs
> To: [log in to unmask]
> Date: Thursday, January 13, 2011, 6:21 PM
> On 1/13/2011 8:51 PM, George
> Brock-Nannestad wrote:
> > From: Patent Tactics, George Brock-Nannestad
> > 
> > 
> > Hello Michael [Shoshani],
> > 
> > you never understood high speed commercial dubbing.
> Well, it was a high speed
> > reproduction of the master 1/4 inch tape and dubbing
> it onto high speed
> > recording cassette tape,
> 
> The duplicators I saw here in the U.S. often used a 1/2
> inch master because it was four track -- both sets of stereo
> tracks were recorded at the same time.  The master was
> in a bin-loop which played over and over and over and over.
> >   collecting the recorded cassette tape
> in a cassette,
> > putting in an empty cassette and recycling the master.
> The cassette tape came
> > from a pancake and was cut.
> 
> They usually recorded the entire pancake from the
> continually repeating bin-loop master.  The recorded
> pancake was placed on the cassette loading machine, and a
> cue tone told the machine where to cut.  The fun part
> is watching the automatic splicing block splice the tape
> onto the middle of the C-0's leader.  Then the tape is
> wound into the cassette until the tone stops it, and then
> the automatic splicer tacks the other half of the leader
> onto the tape and is wound back into the cassette and it
> drops down a chute to the pile of cassettes.  I
> videotaped one of these machines and ought to put it on
> YouTube -- but I bet there already is one.
> 
> 
> >   It was very quick, but there was no
> loss of high
> > frequencies, because that is all dependent on the gap
> length, and that stayed
> > the same. It was a fully automated process, and LYREC
> of Denmark made very
> > good duplicating equipment. The electronic difficulty
> was in the bias
> > frequency, which was in the Megahertz range, and you
> had to be very careful
> > with your stray capacities.
> 
> 
> The interconnect cables were video cables because the
> frequencies were up in the video range.
> 
> > Mechanically it was a challenge, but LYREC did
> > solve that. LYREC machines are still in operation, I
> think, and their last
> > markets were in India and Russia.  Kind regards,
> George
> 
> I think there still might be some going here in the U.S.
> 
> 
> Mike Biel   [log in to unmask]
> > ---------------------------------------
> > 
> > 
> >> On Thu, 2011-01-13 at 19:21 -0500, Tom Fine
> wrote:
> >> 
> >>> But, none of this warm and fuzzy nostalgia
> will make those piece of
> >> garbage pre-duped tapes sold to
> >>> the Walkman Generation sound any better. They
> were disposable junk, and
> >> almost all of them ended up
> >>> in landfills in the 90's, replaced by much
> better sounding CD's. I never
> >> fell for the trap since I
> >>> could dub my own tapes.
> >> Same here. I never understood how high speed
> commercial dubbing worked
> >> in the first place; it seems that all the high
> frequencies would be well
> >> out of the reproduction and recording range of the
> equipment involved.
> >> I made my own LP to cassette dubs, carefully
> setting the recording level
> >> to kick just below -0 db on the loudest passages
> so as not to ride gain
> >> constantly.
> >> 
> >> My children will never know such geeky joys. :)
> >> 
> >> Michael Shoshani
> >> Chicago
> > 
>