"Jim Lesurf" wrote in message
...
In article , fred
bloggs wrote:



It tells you that when you have to align the machine, you should use a
NAB calibration tape to set it up for a flat replay response. It is
usually independent of tape type (although there are minor differences
in the bias level for different tapes), but having said that you should
try to use the same tape type as the one used during the recording
calibration.

You should also bear in mind that since the replay curves are different
you
will find that:

1) Should tapes recorded on your NAB machine be played back on an IEC
machine, the frequency response will be incorrect.

2) Should you play tapes recorded on an IEC machine, the frequency
response
may be incorrect.

Provided that the tapes are not Dolby encoded, this may be a minor matter,
corrected by a tweak of something like a tone control.

IIRC the actual spec is in terms of a difference in the *replay* curves,
and the recorder can then use whatever bias and record curves give the
required replay response for the chosen tape.

Afraid I don't have the curves to hand, and can't recall the details. So I
can't say how noticable the effect may be.

Thanks for that Jim, I have another 2 track revox which does not have the
NAB marking on the sticker.

I am right to conclude that the machine was intended for professional use
with NAB adaptors - possibly for mastering purposes?