[Vintage-Audio] 2Track Vs 4 Track

Thu Aug 5 07:58:41 EDT 2004

Bob, 	

I just happen to have the original tape and a copy of the manual. I got this
from a Ham friend on the west side of Michigan who saw it in a local shop. He
got it for a very small price. Because he is an excellent technician, he checked
it out prior to buying it. Other than some dirt, it looked new.	

he got it home and opened it up. Inside it looked like new. He doubted it had
ever been used, and if so, very very little. He cleaned all controls and the
front panel up, it looks like it just came out of the original box in the
seventies. 			

I did some checking and learned that the Teac AN-180 sold new for $350, no
inexpensive item for the seventies! 	

My cousin, Mr. If It Isn't Classical Or Opera, It Is Not Music, has the AN-60
for his Revox B77. (This Revox had no Dolby for those are wondering.) It looks
like a little toy compared to this complex machine with knobs, switches, meters,
jacks and so forth.	

It was tested and passed perfectly. Fully functional with all components within
tolerances.	

I do not truly understand what I am about to say, so know that at the outset! 	

I have heard that once upon a time commercial FM stations broadcast in a format
that required, or could use, a product like the Teac AN-180 to equalize the
incoming signal. This practice was shortlived though and was quickly dropped.
What was this all about? I know it was supposed to improve the frequency and/or
quality of the broadcast signal. Did it and if so, why was it dropped, and so
quickly? Simply not practical? More hype than fact? Cost too much for the
obvious improvement to temtp the consumers, as in passing fad? 		

It appears that one can add Dolby to anything you can plug into this item. 	

Duane W8DBF	

----------
From: wolfbob <wolfbob at csnsys.com>
To: Vintage home and professional audio equipment from 1975 back
<vintage-audio at mailman.qth.net>
Subject: Re: [Vintage-Audio] 2Track Vs 4 Track
Date: Thursday, August 05, 2004 1:58 AM

True, if nothing changes. The tape is an easy one to get. Someone with a
calibrated deck can make you a tape at 185nWb/m fluxivity and I believe 700
Hz. This is dB or the reference level for Dolby systems. dbx systems use
1000 Hz at 185 nWb/m. The frequency is the crossover point for the
compression and needs to be correct.

WBob

----- Original Message ----- 
From: "Duane Fischer, W8DBF" <dfischer at usol.com>
To: "Vintage home and professional audio equipment from 1975 back"
<vintage-audio at mailman.qth.net>
Sent: Wednesday, August 04, 2004 9:08 PM
Subject: Re: [Vintage-Audio] 2Track Vs 4 Track

> Bob,
>
> How does the calibration tape work for the Teac AN-180 external Dolby and
> equalization unit? It is my understanding that once it is calibrated, the
tape
> is not needed again. True or myth?
>
> Duane W8DBF
>
>
>
> ----------
> From: wolfbob <wolfbob at csnsys.com>
> To: Mark - AA6DX <aa6dx at pacbell.net>; Vintage home and professional audio
> equipment from 1975 back <vintage-audio at mailman.qth.net>
> Subject: Re: [Vintage-Audio] 2Track Vs 4 Track
> Date: Wednesday, August 04, 2004 11:30 PM
>
> No sorry but wrong again. All the test tapes I have (about 12) all are
full
> track and are not ever used to align the heads in any dinmension that
would
> influence crosstalk. That is done by mechanical alignment of the tape
edges
> and the head gaps. Test tapes are used for setting levels, aligning
azimuth
> and correcting equalization, not for setting where the tape goes by the
> heads. Again after aligning, testing and using about three different 1/4
> inch 4 track reel to reel decks per week for the last five years, that I
> have never heard ANY crosstalk on an aligned deck either with it's own or
> other decks tape or with prerecorded tapes (which I have about 100). You
> possibly are mistaking print through for crosstalk.
>
> If you think the gap spacing is tight in 1/4 inch 4 track, it is the same
as
> 1/2 inch 8 track and 1 inch 16 track, the very popular standards for the
> recording industry. Carrying it to an extreme look at the cassette where
you
> have 4 tracks in 1/8 inch or so. Yet the cassette is not driven by the
> appearance of any crosstalk.
>
> Now it was a problem in the decks made in the early 40s before they
figured
> out how to get some shielding between the gaps, but all of the Japanese,
> most of the US and all but some early European decks have never had this
> problem. Certainly any 4 track stereo deck used adequate shielding and
> therefore no crosstalk as they were all built after about 1950.
>
> WBob
>
>
> ----- Original Message ----- 
> From: "Mark - AA6DX" <aa6dx at pacbell.net>
> To: "Vintage home and professional audio equipment from 1975 back"
> <vintage-audio at mailman.qth.net>
> Sent: Wednesday, August 04, 2004 7:15 PM
> Subject: Re: [Vintage-Audio] 2Track Vs 4 Track
>
>
> > Cross talk is indeed an issue.  One may never hear crosstalk on a
properly
> > aligned 4 track, but, if you purchase pre- recorded tapes, or the
product
> > comes from a different recorder, you may well have your recording
invaded
> by
> > other way sound.  Industry standard test tapes are designed to eliminate
> > this problem, but a lot of audiophiles never bothered, because the tapes
> > played back swell on their own machine.  Signal to noise is very
> > important... but so is equalization and head room.  As an aside, most
home
> > users did not set their equalization to match their chosen brand and
> > specific blank tape, and lost much of the quality they hoped to gain by
> the
> > expenditure for the "high priced spread".
> >
> > Why do you suppose the broadcast industry universally uses half track?
> > Surely not so they can spend more money on tape!  If your local radio
> > station gets its ads (hopefully for your favorite presidential
candidate)
> > via ancient reel to reel tape, it will be half track.
> >
> > 15 IPS and half track was (or is, I don't know) the professional
standard
> > for high fidelity stereo content using 1/4" tape.  One inch tape if you
> were
> > serious, and could afford the hardware.
> >
> > I spent 10 years in the sales part of audio, and 10 years in Broadcast,
> and
> > throw in a few years in the advertising agency business.  But there are
> > those who know more than I.
> >
> > Far West Mark
> >
> >
> >
> > _______________________________________________
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> > List Administrator: Duane Fischer, W8DBF
> > ** For Assistance: dfischer at usol.com **
> >
> >
> >
>
>
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