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Re: [ARSCLIST] NAB vs. DIN recordings
Hi Richard:
If the low-freq fringeing effects are common, that's one thing, but except for a classical music
master made in a very quiet room with a very quiet recording rig, I doubt 1.7dB s/n degradation is
very audible.
The worst thing I've encountered with half-tracks were a bunch of tapes where the guy made
recordings on "side A" on his first machine in the 1950's and then decided he'd record on "side B"
with his new machine in the late 60's. Neither was in "standard" azimuth per my MRL tape and they
weren't in azimuth to each other. Hence, twice the time needed to do a proper transfer than the
normal MO of ingesting both tracks at once and reversing "side B" in the computer. These recordings,
BTW, were off AM radio and sounded amazingly good. I couldn't believe that as late as the early
70's, AM radio had reasonably good fidelity, at least through this guy's tuner and tape recorder.
-- Tom Fine
----- Original Message -----
From: "Richard L. Hess" <arclists@xxxxxxxxxxxxxxx>
To: <ARSCLIST@xxxxxxxxxxxxxxxx>
Sent: Sunday, March 25, 2007 7:34 PM
Subject: Re: [ARSCLIST] NAB vs. DIN recordings
At 05:30 PM 2007-03-25, Tom Fine wrote:
How much quality/fidelity do you use if you play back something recorded with a 2.8mm head on a
1.9mm head? It would seem like you'd be safest using the narrowest track width as it should play
everything at least OK and not pick up any outside-of-track garbage from a tape, no?
Hi, Tom,
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.