Re: [ARSCLIST] NAB vs. DIN recordings

[Eric Jacobs <EricJ@xxxxxxxxxxxxxxxxxxx>]

Hi Richard,

What's your favorite tool for measuring recorded track width on 
a tape?  I use the Arnold B-1022 Magnetic Viewer, but it's not
the easiest tool on the planet to use - it's sometimes hard to
see the tracks.

FYI, the 2.8mm track width works out to 110.2 mils.  Do the 
standards for track widths specify them in millimeters or mils?

If I understand correctly from your email, mismatching track 
widths (head vs recorded track) primarily influences noise 
(fringing), but not EQ?

For the record:

I have a Studer A810 which originates from the Seattle area 
which has DIN heads.  I need to check if it was originally a 
CBC machine, but I don't think so.

I also have a Studer A810 from Universal Studios - in great
shape, low mileage, high serial number - with NAB TC.

My other Studer A810, which is a CBC machine, has NAB (no TC).

My Studer A820 is NAB TC.  It originates from Newfoundland
and has an Ontario power sticker on it.

It's rumored that the DIN heads reduce the need to swap head
stacks when switching between full-track mono and half-track
stereo recordings.  If so, might this flexibility be a 
potential explanation for the prevalence of the DIN heads?
Might there be other performance advantages to the DIN heads
that made them popular?

Eric Jacobs
The Audio Archive
tel: 408.221.2128
fax: 408.549.9867
mailto:EricJ@xxxxxxxxxxxxxxxxxxx



-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:ARSCLIST@xxxxxxx]On Behalf Of Richard L. Hess
Sent: Sunday, March 25, 2007 4:34 PM
To: ARSCLIST@xxxxxxxxxxxx
Subject: Re: [ARSCLIST] NAB vs. DIN recordings


<SNIP>

If you use a too-narrow track, you get low-frequency fringing 
effects. The worst case of signal-to-noise degradation would be
10 log (1.9/2.8) or about - 1.7 dB.

I am interested in David Lennick's comments as to the wide 
utilization of the DIN heads (2.8 mm tracks) throughout CBC).

I wonder if the EQ was NAB or IEC?

I just cleaned a couple of moldy CBC Toronto tapes and they are 
indeed DIN track width. They sound like NAB EQ, however.

I tend to ignore the 1.9 vs 2.1 mm track width. I prefer to think in 
mils (thousandths of an inch). So we have roughly 75 mils for the 
Ampex original stereo heads (the original half-track mono heads were 
always about 82 mils). Then the 82 mils became standardized for 
half-track mono AND stereo in the NAB standard I think about 1965. 
Then, of course, we have the 100 mil (102?) DIN standard.

I did come across one "half-track" recording that had 60 mil tracks 
on it. Joy. I just used the 82 mil normal head (I don't have any 
Ampexes so I don't have any 75 mil heads).

Anyway, I just dug out my butterfly head assembly and I'll put it on 
my A810 and align it.

I'd love more discussion on the pervasiveness of this. I have some 
machines from CBC-TV in Montreal and they were all NAB Timecode, no 
DIN heads there.

Cheers,

Richard


Richard L. Hess                   email: richard@xxxxxxxxxxxxxxx
Aurora, Ontario, Canada       (905) 713 6733     1-877-TAPE-FIX
Detailed contact information: http://www.richardhess.com/tape/contact.htm
Quality tape transfers -- even from hard-to-play tapes.