Hello all, I have a Revox B77 MKII. On the rear sticker it states 2 track
NAB, however I do not have any NAB adaptors and the machine is fitted with
the normal spring loaded clips for reel attachment.

I don't understand why the machine is labelled as NAB, as I thought this was
a reversible option depending on adaptors fitted.

The machine is high speed (7 / 15)

Can anybody shed some light on this?

Thanks

"Oddjob" wrote in message
...
Hello all, I have a Revox B77 MKII. On the rear sticker it states 2 track
NAB, however I do not have any NAB adaptors and the machine is fitted with
the normal spring loaded clips for reel attachment.

I don't understand why the machine is labelled as NAB, as I thought this
was
a reversible option depending on adaptors fitted.

The machine is high speed (7 / 15)

Can anybody shed some light on this?

Thanks

Hi Oddjob

this may be referring to the equalisation used for recording - there are two
major ones - IEC and NAB.

Cheers, Mike

In article , fred
bloggs writes

"Oddjob" wrote in message
.. .
Hello all, I have a Revox B77 MKII. On the rear sticker it states 2 track
NAB, however I do not have any NAB adaptors and the machine is fitted with
the normal spring loaded clips for reel attachment.

I don't understand why the machine is labelled as NAB, as I thought this
was
a reversible option depending on adaptors fitted.

The machine is high speed (7 / 15)

Can anybody shed some light on this?

Thanks

Hi Oddjob

this may be referring to the equalisation used for recording - there are two
major ones - IEC and NAB.

Cheers, Mike



Yes that's what its referring to. The NAB big hole reels are catered for
by NAB adapters.

Wasn't they called NARTB once?...
--
Tony Sayer

"fred bloggs" wrote in message
...

"Oddjob" wrote in message
...
Hello all, I have a Revox B77 MKII. On the rear sticker it states 2
track
NAB, however I do not have any NAB adaptors and the machine is fitted
with
the normal spring loaded clips for reel attachment.

I don't understand why the machine is labelled as NAB, as I thought this
was
a reversible option depending on adaptors fitted.

The machine is high speed (7 / 15)

Can anybody shed some light on this?

Thanks

Hi Oddjob

this may be referring to the equalisation used for recording - there are
two
major ones - IEC and NAB.

Thanks for that Mike, I was only aware of equalisation for different tape
types and thought that 1/2 inch tape was mostly ferric.

Does this mean that the machine is set-up for NAB tape type and will give
best results when this is used?

"Oddjob" wrote in message
...

"fred bloggs" wrote in message
...

"Oddjob" wrote in message
...
Hello all, I have a Revox B77 MKII. On the rear sticker it states 2
track
NAB, however I do not have any NAB adaptors and the machine is fitted
with
the normal spring loaded clips for reel attachment.

I don't understand why the machine is labelled as NAB, as I thought
this
was
a reversible option depending on adaptors fitted.

The machine is high speed (7 / 15)

Can anybody shed some light on this?

Thanks

Hi Oddjob

this may be referring to the equalisation used for recording - there are
two
major ones - IEC and NAB.

Thanks for that Mike, I was only aware of equalisation for different tape
types and thought that 1/2 inch tape was mostly ferric.

Does this mean that the machine is set-up for NAB tape type and will give
best results when this is used?


Hi again,

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.

I hope that's clear
Cheers, Mike

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.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

In article ,
Oddjob wrote:
Hello all, I have a Revox B77 MKII. On the rear sticker it states 2
track NAB, however I do not have any NAB adaptors and the machine is
fitted with the normal spring loaded clips for reel attachment.

I don't understand why the machine is labelled as NAB, as I thought this
was a reversible option depending on adaptors fitted.

The machine is high speed (7 / 15)

Can anybody shed some light on this?

NAB refers to the recording equalisation. It should have switchable replay
eq - NAB or CCIR (IEC)

In the days of purchase tax, some A77 machines were sold with fixed NAB
adaptors with no PT - seems the tax people thought that meant pro use only.

--
*How do they get the deer to cross at that yellow road sign?

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Jim Lesurf wrote:
2) Should you play tapes recorded on an IEC machine, the frequency
response may be incorrect.

I'm pretty certain it has switchable replay eq.

--
*The most common name in the world is Mohammed *

Dave Plowman London SW
To e-mail, change noise into sound.

"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?

"Dave Plowman (News)" wrote in message
...
In article ,
Jim Lesurf wrote:
2) Should you play tapes recorded on an IEC machine, the frequency
response may be incorrect.

I'm pretty certain it has switchable replay eq.

Dave, the machine does not have any switch - well I can't find one.

Thanks to everyone who has contributed to this query.