[Tape Guy]

Seems that Tandberg or Nakamichi or Revox tape decks get all the press
when it comes to high end machines.

Are there any tech specs for them? Frequency and phase response, S/N
ratio?

I've got an Akai GX-A5X with Dolby B, C and DBX noise reduction, and was
wondering how such a deck compares to these so-called high-end machines?

Akai's specs list the frequency response at 20 to 19khz +/- 3db using
metal tape.

S/N listed as 60 db (metal) and 75-80 db with Dolby C. DBX is listed as
115 db (dynamic range, not S/N).

Wow and flutter: 0.05% (WRMS), 0.12% (DIN WTD).

Distortion: 0.65% (metal)

There seem to be quite a lot of Akai decks with model numbers starting
with GX. Why so many different models? Which Akai deck was the best?

[Scott Dorsey]

In article , Tape Guy wrote:
Seems that Tandberg or Nakamichi or Revox tape decks get all the press
when it comes to high end machines.

Are there any tech specs for them? Frequency and phase response, S/N
ratio?

Yes, they are on the data sheet.

For the most part, they all have godawful flutter specifications. And
unless you adjust the bias properly for the particular kind of tape
and set the Dolby levels correctly, the frequency response numbers on
the data sheet are meaningless.

One of the major differences between the high end machines and the
cheaper machines is that they allow you to actually set bias and level
properly for the tape you are using, without having to open the case.
They also allow you to adjust the azimuth properly for correct playback
in most cases, because it's always wrong.

i've got an Akai GX-A5X with Dolby B, C and DBX noise reduction, and was
wondering how such a deck compares to these so-called high-end machines?

Akai's specs list the frequency response at 20 to 19khz +/- 3db using
metal tape.

Those are not really meaningful, unless they are measured with precisely
the metal tape the test was done with. They also imply (especially that
-3dB at 19 KC part) that the azimuth is correct, which it never is.
So that's really not anything you should expect to see in the real world.

S/N listed as 60 db (metal) and 75-80 db with Dolby C. DBX is listed as
115 db (dynamic range, not S/N).

These also are very optimistic numbers, but again imply the levels are
set precisely so that the reference tone levels match up and the NR
system doesn't start pumping. Again in the real world this is never
the case.

Wow and flutter: 0.05% (WRMS), 0.12% (DIN WTD).

That's what I would consider to be intolerably high, but it's not out of
line for cassettes.

distortion: 0.65% (metal)

This is a meaningless number because it does not include a reference level.
At some point I hope the distortion is much lower than that, and at some
point you can increase the operating level so it is much higher. It also
is very dependant on the tape itself.

There seem to be quite a lot of Akai decks with model numbers starting
with GX. Why so many different models? Which Akai deck was the best?

Because Akai has been in business for something like fifty years now, and
they made a lot of products over that time period. I think asking
which cassette deck is best is like asking what kind of sewage tastes
best... they are all pretty dreadful.

In the real world, the cassette deck that sounds best is the one that
is most correctly adjusted. That means either automatic or vernier
azimuth control on playback, and it means bias and level controls on
the front panel.

The rest of the issues you just live with... cassettes have a whole lot
of flutter and you will never get a piano to sound right because of the
flutter modulation. Life's just like that. You live with it.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Mr.T]

"Scott Dorsey" wrote in message
...
There seem to be quite a lot of Akai decks with model numbers starting
with GX. Why so many different models?

Because Akai has been in business for something like fifty years now, and
they made a lot of products over that time period.

True, but misses the reason that "GX" was Akai's original term for their
"Glass and Crystal (Glass-Xtal) ferrite heads", and they seemed to stick
with it.
Similarly in the days of their R-R machines, the X model numbers came from
their designation of "Cross (X) Field Heads", a lot of those too.

MrT.

[Mr.T]

"Scott Dorsey" wrote in message
...
The rest of the issues you just live with... cassettes have a whole lot
of flutter and you will never get a piano to sound right because of the
flutter modulation. Life's just like that. You live with it.

Actually no, you dump them in the nearest garbage bin and move to CD
recording like many of us did over a decade ago.
And before then the people who wanted HiFi used R-R machines rather than
overpriced cassette machines like the Nakamichi's which were *far* inferior
in every way to a similar priced (and even far cheaper) R-R, except for
convenience, and tape cost.
The only real use of cassette I ever found was in car entertainment until
car CD players put an end to that, thank god!

MrT.

[Tape Guy]

Scott Dorsey wrote:

Akai's specs list the frequency response at 20 to 19khz +/- 3db
using metal tape.

Those are not really meaningful, unless they are measured with
precisely the metal tape the test was done with. They also
imply (especially that -3dB at 19 KC part) that the azimuth
is correct, which it never is.

If I'm only going to be playing back the tapes that were recorded by the
same deck, then how important or how critical is the azimuth setting in
that case? As long as I don't change it, it should be ajusted perfectly
when playing back the material that it recorded previously - no? (this
deck has a single play/record head).

[David Nebenzahl]

On 2/27/2009 7:51 PM Mr.T spake thus:

"Scott Dorsey" wrote in message
...

The rest of the issues you just live with... cassettes have a whole lot
of flutter and you will never get a piano to sound right because of the
flutter modulation. Life's just like that. You live with it.

Actually no, you dump them in the nearest garbage bin and move to CD
recording like many of us did over a decade ago.
And before then the people who wanted HiFi used R-R machines rather than
overpriced cassette machines like the Nakamichi's which were *far* inferior
in every way to a similar priced (and even far cheaper) R-R, except for
convenience, and tape cost.
The only real use of cassette I ever found was in car entertainment until
car CD players put an end to that, thank god!

Maybe not.

Years ago (long predating digital), some friends of mine in a local band
produced their EP[1] using a Teac Portastudio--you know, the little
4-track cassette recorder. It was done in a studio, with good mikes, but
using this minimalist equipment.

The record sounded great, and still measures up to similar recordings of
the time. So maybe a little less snobbery here, huh?


[1] For those who think a "record" is a CD, stands for "extended play",
a small 7" record revolving at 33-1/3.


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

[David Nebenzahl]

On 2/27/2009 8:00 PM Tape Guy spake thus:

Scott Dorsey wrote:

Akai's specs list the frequency response at 20 to 19khz +/- 3db
using metal tape.

Those are not really meaningful, unless they are measured with
precisely the metal tape the test was done with. They also
imply (especially that -3dB at 19 KC part) that the azimuth
is correct, which it never is.

If I'm only going to be playing back the tapes that were recorded by the
same deck, then how important or how critical is the azimuth setting in
that case? As long as I don't change it, it should be ajusted perfectly
when playing back the material that it recorded previously - no? (this
deck has a single play/record head).

True to some extent--it's bad if the record and playback azimuths
differ--but the azimuth still needs to be perpendicular to tape travel
for best results.

I can't believe that these Akais are somehow *more* prone to bad azimuth
settings than other cassette decks. I sense a bit of snobbery in some of
these responses. What cassette deck does *not* have azimuth-setting
problems? Basically, if any decent deck is properly adjusted, and is not
dropped or hammered upon, the azimuth setting should be fine. This is
normally done at the factory when the thing is assembled. (Unless
someone has evidence that Akai was lazy about azimuth adjustment.)


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

[Tape Guy]

David Nebenzahl wrote:

If I'm only going to be playing back the tapes that were recorded
by the same deck, then how important or how critical is the azimuth
setting in that case?

True to some extent--it's bad if the record and playback azimuths
differ-

How can they differ if they're both integrated into the same head?

-but the azimuth still needs to be perpendicular to tape travel
for best results.

Cosine law says that you can have a wide variance (in terms of degrees
away from 90) and still be essentially perpendicular.


--
Incidentally, my company motto is "If this stuff worked, you
wouldn't need me".
- lifted from sci.electronics.repair

Microsoft's motto: If it works, it's not complicated enough.

[[email protected]]

On Feb 27, 10:43*pm, "Mr.T" MrT@home wrote:
"Scott Dorsey" wrote in message

...

There seem to be quite a lot of Akai decks with model numbers starting
with GX. *Why so many different models?

Because Akai has been in business for something like fifty years now, and
they made a lot of products over that time period.

True, but misses the reason that "GX" was Akai's original term for their
"Glass and Crystal (Glass-Xtal) ferrite heads", and they seemed to stick
with it.
Similarly in the days of their R-R machines, the X model numbers came from
their designation of "Cross (X) Field Heads", a lot of those too.

MrT.

Yes, I think the glass crystal heads are the GXC machines, and I had
very good luck with one of those.. Mr Dorsey of course is correct,
in a cassette machine its all about the azimuth adj.

Ask someone about the machine (not Akai) with the auto azimuth adj, if
you have a lot of tapes to playback you might consider one of
those.....I never had one, I can't tell you about it.


Mark

[David Nebenzahl]

On 2/27/2009 8:44 PM Tape Guy spake thus:

David Nebenzahl wrote:

If I'm only going to be playing back the tapes that were recorded
by the same deck, then how important or how critical is the azimuth
setting in that case?

True to some extent--it's bad if the record and playback azimuths
differ-

How can they differ if they're both integrated into the same head?

They can differ if a tape is recorded on one machine and played back on
another with different azimuth; that's what I meant.

-but the azimuth still needs to be perpendicular to tape travel
for best results.

Cosine law says that you can have a wide variance (in terms of degrees
away from 90) and still be essentially perpendicular.

But perfectly perpendicular is still better. You can work it out on
paper: tape speed = 1-7/8 ips, frequency = 10K ... if azimuth is off,
high frequencies start disappearing, for one thing.


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

[David Nebenzahl]

On 2/27/2009 8:51 PM spake thus:

Ask someone about the machine (not Akai) with the auto azimuth adj, if
you have a lot of tapes to playback you might consider one of
those.....I never had one, I can't tell you about it.

Curious about this: never heard of a cassette machine with auto azimuth
adjustment. On the fly? Some kind of servo mechanism? How does/did that
work?


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

[Paul Stamler[_2_]]

"Tape Guy" wrote in message ...
Seems that Tandberg or Nakamichi or Revox tape decks get all the press
when it comes to high end machines.

Are there any tech specs for them? Frequency and phase response, S/N
ratio?

I've got an Akai GX-A5X with Dolby B, C and DBX noise reduction, and was
wondering how such a deck compares to these so-called high-end machines?

Badly.

Here's the problem, and it doesn't show up in specs that any manufacturer
ever quotes. Cassettes suck in many ways, but one of the biggest is that
each cassette incorporates a pressure pad to hold the tape against the head.
This adds a large amount of "scrape flutter", aka "modulation noise" to the
signal -- the tape speed is altered, and the audio frequency modulated, by a
noise signal. You hear it as "roughness", which tracks the signal level.
It's measurable, for sure, but nobody ever quotes it, because cassettes do
such a lousy job at it.

Except Nakamichi 3-head twin-capstan decks. They have ridges on either side
of the head assenbly which push the pressure pad away from the tape,
drastically cutting down the scrape flutter. They maintain tape tension with
the dual capstans.

Nobody else did this, because Nakamichi either bought the patent or obtained
an exclusive license on it from the folks who invented it (Eumig).

As a result, there are two categories of cassette decks: Nakamichi
three-head decks and everything else.

Akai's specs list the frequency response at 20 to 19khz +/- 3db using
metal tape.

S/N listed as 60 db (metal) and 75-80 db with Dolby C. DBX is listed as
115 db (dynamic range, not S/N).

And it'll sound terrible, too.

Wow and flutter: 0.05% (WRMS), 0.12% (DIN WTD).

Distortion: 0.65% (metal)

At what frequency, at what level, what kind of test? A single distortion
number, unfortunately, tells little or nothing.

There seem to be quite a lot of Akai decks with model numbers starting
with GX. Why so many different models?

It's called marketing; they designed one for every possible price point.

Which Akai deck was the best?

None of them. See above.

Peace,
Paul

[Paul Stamler[_2_]]

"David Nebenzahl" wrote in message
.com...
On 2/27/2009 8:51 PM spake thus:

Ask someone about the machine (not Akai) with the auto azimuth adj, if
you have a lot of tapes to playback you might consider one of
those.....I never had one, I can't tell you about it.

Curious about this: never heard of a cassette machine with auto azimuth
adjustment. On the fly? Some kind of servo mechanism? How does/did that
work?

Nakamichi Dragon. One of the tracks on the playback head was split -- two
sections, each reading half of the track. A detector looked for phase
differences in the high frequencies due to azimuth errors, and a small motor
adjusted the head to the least phase difference.

Peace,
Paul

[Mr.T]

"David Nebenzahl" wrote in message
.com...
The only real use of cassette I ever found was in car entertainment
until
car CD players put an end to that, thank god!

Maybe not.

Years ago (long predating digital), some friends of mine in a local band
produced their EP[1] using a Teac Portastudio--you know, the little
4-track cassette recorder. It was done in a studio, with good mikes, but
using this minimalist equipment.

The record sounded great, and still measures up to similar recordings of
the time. So maybe a little less snobbery here, huh?

Nope, I had the misfortune to use a Teac Portastudio once, in fact a friend
still owns one which he never uses anymore since going digital a decade ago.
My current MOTU and M-Audio rigs outperform a Teac portastudio by several
orders of magnitude in all parameters, and are also far superior to my reel
to reel decks, so anyone claiming a Teac portastudio stands up these days is
talking out his ase!

MrT.

[David Nebenzahl]

On 2/28/2009 2:18 AM Mr.T spake thus:

"David Nebenzahl" wrote in message
.com...

The only real use of cassette I ever found was in car
entertainment until car CD players put an end to that, thank
god!

Maybe not.

Years ago (long predating digital), some friends of mine in a local band
produced their EP[1] using a Teac Portastudio--you know, the little
4-track cassette recorder. It was done in a studio, with good mikes, but
using this minimalist equipment.

The record sounded great, and still measures up to similar recordings of
the time. So maybe a little less snobbery here, huh?

Nope, I had the misfortune to use a Teac Portastudio once, in fact a friend
still owns one which he never uses anymore since going digital a decade ago.
My current MOTU and M-Audio rigs outperform a Teac portastudio by several
orders of magnitude in all parameters, and are also far superior to my reel
to reel decks, so anyone claiming a Teac portastudio stands up these days is
talking out his ase!

Reread my post: I didn't claim that a Portastudio would "stand up" to
today's equipment. I said it was more than adequate for a recording made
more than a couple decades ago.


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

[Scott Dorsey]

Mr.T MrT@home wrote:
"Scott Dorsey" wrote in message
...
There seem to be quite a lot of Akai decks with model numbers starting
with GX. Why so many different models?

Because Akai has been in business for something like fifty years now, and
they made a lot of products over that time period.

True, but misses the reason that "GX" was Akai's original term for their
"Glass and Crystal (Glass-Xtal) ferrite heads", and they seemed to stick
with it.

Yes, this is true. Although today we'd just call those ferrite heads.

Similarly in the days of their R-R machines, the X model numbers came from
their designation of "Cross (X) Field Heads", a lot of those too.

God, I hope I never see another one of those pieces of crap ever again...
I think I still have a few bins of Roberts parts in the warehouse.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Tape Guy]

Paul Stamler wrote:

I've got an Akai GX-A5X with Dolby B, C and DBX noise reduction,
and was wondering how such a deck compares to these so-called high-
end machines?

Badly.

each cassette incorporates a pressure pad to hold the tape against
the head. This adds a large amount of "scrape flutter", aka
"modulation noise" to the signal

Except Nakamichi 3-head twin-capstan decks.

That's cool.

How much time do you spend adjusting the play and record heads so they
track each other?

Akai's specs list the frequency response at 20 to 19khz +/-
3db using metal tape.

S/N listed as 60 db (metal) and 75-80 db with Dolby C. DBX
is listed as 115 db (dynamic range, not S/N).

And it'll sound terrible, too.

Sounds great. What's the Nakamichi's frequency response and S/N ratio?
Does it have DBX?

Wow and flutter: 0.05% (WRMS), 0.12% (DIN WTD).

Distortion: 0.65% (metal)

At what frequency, at what level, what kind of test? A single
distortion number, unfortunately, tells little or nothing.

Is Wow and flutter frequency dependent?

What are the Nakamichi's numbers?

[Scott Dorsey]

Mr.T MrT@home wrote:
"Scott Dorsey" wrote in message
The rest of the issues you just live with... cassettes have a whole lot
of flutter and you will never get a piano to sound right because of the
flutter modulation. Life's just like that. You live with it.

Actually no, you dump them in the nearest garbage bin and move to CD
recording like many of us did over a decade ago.

Unfortunately there's a lot of stuff recorded on cassette out there, and
folks need to transcribe it. That's why the high end cassette decks are
still fetching good money. And let me reiterate that if you are doing
transcription of old tapes, you absolutely need to be able to change the
head alignment and the reference levels.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

In article , Tape Guy wrote:
If I'm only going to be playing back the tapes that were recorded by the
same deck, then how important or how critical is the azimuth setting in
that case? As long as I don't change it, it should be ajusted perfectly
when playing back the material that it recorded previously - no? (this
deck has a single play/record head).

Indeed, if you're never going to interchange tapes, the need for accurate
azimuth is reduced. But if you're not going to interchange tapes, why
use cassette at all?
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

David Nebenzahl wrote:
I can't believe that these Akais are somehow *more* prone to bad azimuth
settings than other cassette decks. I sense a bit of snobbery in some of
these responses. What cassette deck does *not* have azimuth-setting
problems?

The Nak Dragon doesn't, since it has an automatic azimuth setting system.
Some Tascam models and a couple other Nak models don't since they have
vernier controls to accurately adjust the azimuth.

Basically, if any decent deck is properly adjusted, and is not
dropped or hammered upon, the azimuth setting should be fine.

I have never seen a cassette deck in my life with correct record azimuth.
And of course, once you use a different cassette shell than you set the
machine up with, it's different again. I very frequently get tapes for
transcription where the azimuth wanders from the beginning to the end of
the tape, and where the two sides seem to have different azimuth. It's
just not a stable transport mechanism.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

In article , Tape Guy wrote:

How can they differ if they're both integrated into the same head?

If the head gaps aren't parallel. But that's ANOTHER huge set of
nightmarish cassette issues.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

David Nebenzahl wrote:
On 2/27/2009 8:51 PM spake thus:

Ask someone about the machine (not Akai) with the auto azimuth adj, if
you have a lot of tapes to playback you might consider one of
those.....I never had one, I can't tell you about it.

Curious about this: never heard of a cassette machine with auto azimuth
adjustment. On the fly? Some kind of servo mechanism? How does/did that
work?

He's talking about the Nak Dragon or one of the imitators. They have
in addition to the normal head gaps, an alignment head with very narrow
tracks, two of which subtend the actual track recorded on the cassette.

There is a phase comparator circuit that looks at the theta between the
two tracks and moves the head back and forth until they are locked.

Not only does this set the azimuth correctly, but it keeps the azimuth
locked on as the tape rolls, which is a wonderful thing when you have
tapes with azimuth drift to deal with.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

David Nebenzahl wrote:

Reread my post: I didn't claim that a Portastudio would "stand up" to
today's equipment. I said it was more than adequate for a recording made
more than a couple decades ago.

I would tend to disagree. There was a pretty good market for 1" and 2"
studio decks back then....
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[[email protected]]

-but the azimuth still needs to be perpendicular to tape travel
for best results.

Cosine law says that you can have a wide variance (in terms of degrees
away from 90) and still be essentially perpendicular.



I disagreee with that, the gap is on the order of 1 micron, even a
slight mis-alignment of the angle in effect increases the gap width
which directly reduces the high frequency response limit.

THe azimuth setting on a cassette deck is one of the most critical
settings in all of electronics land. And it's even more critical if
you ever sum the L and R channels into mono.


Mark

[Paul Stamler[_2_]]

"Tape Guy" wrote in message ...
Paul Stamler wrote:

I've got an Akai GX-A5X with Dolby B, C and DBX noise reduction,
and was wondering how such a deck compares to these so-called high-
end machines?

Badly.

each cassette incorporates a pressure pad to hold the tape against
the head. This adds a large amount of "scrape flutter", aka
"modulation noise" to the signal

Except Nakamichi 3-head twin-capstan decks.

That's cool.

How much time do you spend adjusting the play and record heads so they
track each other?

None; they're mounted in a common housing.

Akai's specs list the frequency response at 20 to 19khz +/-
3db using metal tape.

S/N listed as 60 db (metal) and 75-80 db with Dolby C. DBX
is listed as 115 db (dynamic range, not S/N).

And it'll sound terrible, too.

Sounds great. What's the Nakamichi's frequency response and S/N ratio?
Does it have DBX?

There are quite a few different models of Nakamichi, all with different
specs. However, the frequency responses and S/N ratios vary all over the
place, depending on what type of tape is used. Because of that, published
specs for cassette decks are not comparable with one another.

So far as I know, Nakamichi never made a model with dbx.

Wow and flutter: 0.05% (WRMS), 0.12% (DIN WTD).

Distortion: 0.65% (metal)

At what frequency, at what level, what kind of test? A single
distortion number, unfortunately, tells little or nothing.

Is Wow and flutter frequency dependent?

Wow and flutter are measurements of mechanical imperfections in the
transport, and have nothing to do with the frequency on the tape except
inasmuch as they frequency-modulate it.

What are the Nakamichi's numbers?

There are so many Naks that you'd be better off looking up a particular
model's numbers on the net. Bear in mind, though, that comparisons between
published frequency responses and S/N ratios are meaningless, and
wow/flutter numbers can be deceiving unless you know exactly how the
performance is being measured and weighted. That says, essentially, that you
can profitably compare wow/flutter numbers between the products of one
manufacturer, but not between different manufacturers.

Peace,
Paul

[Tape Guy]

wrote:

I disagreee with that, the gap is on the order of 1 micron, even a
slight mis-alignment of the angle in effect increases the gap width
which directly reduces the high frequency response limit.

Even though I've messed with the tape head adjustment screws on other
decks in the distance past, perhaps there's something I don't
understand.

If the magnetized region on the tape has a certain width, then I would
think that you want to do two things with the head adjustment:

a) move the head so that the coil gap is centered directly over the
center of the magnetized region.

b) adjust the head angle so that the coil gap is perpendicular to the
magnetized track.

I don't see how both (a) and (b) can be done with only a single screw
adjustment. If there is only 1 adjustment screw, then you can turn it
so that you achieve (a) but the result might not mean the gap in the
head is perpendicular to the track. If you turn the screw some more,
you might achieve (b), but the gap might not be centered over the track
(but it will be perpendicular to it).

Am I right, or am I missing something here?

And again, if I am mainly concerned with tapes that are recorded and
played back on the same deck, then how critical is this adjustment so
long as it doesn't change over the long term?

And to what extent is a mis-alignment built into heads that contain both
recording and playback coils?

Some of the comments here seem to indicate that a head with combined
record and playback coils can never be as perfectly aligned as a deck
with separate recording and playback heads. I can't see the logic in
that argument.

[D.M. Procida]

Tape Guy wrote:

Some of the comments here seem to indicate that a head with combined
record and playback coils can never be as perfectly aligned as a deck
with separate recording and playback heads. I can't see the logic in
that argument.

The issue there is that different characteristics are required for play
and record heads. Combined record/playback heads are a compromise.

Daniele
--
For sale: iBook G4 1.33MHz, 1.5GB RAM, super condition
http://search.ebay.co.uk/220368472534

[Scott Dorsey]

In article , Tape Guy wrote:

If the magnetized region on the tape has a certain width, then I would
think that you want to do two things with the head adjustment:

a) move the head so that the coil gap is centered directly over the
center of the magnetized region.

This is the head height adjustment.

b) adjust the head angle so that the coil gap is perpendicular to the
magnetized track.

This is the azimuth adjustment.

I don't see how both (a) and (b) can be done with only a single screw
adjustment. If there is only 1 adjustment screw, then you can turn it
so that you achieve (a) but the result might not mean the gap in the
head is perpendicular to the track. If you turn the screw some more,
you might achieve (b), but the gap might not be centered over the track
(but it will be perpendicular to it).

The azimuth is the important part. The height can be off a little bit
and you can get away with it.

If you look at the mount on a regular studio tape recorder, you will
see at least four different adjustments. Sadly there isn't much room
in a cassette deck to built mounts like this.

And again, if I am mainly concerned with tapes that are recorded and
played back on the same deck, then how critical is this adjustment so
long as it doesn't change over the long term?

It changes over the long term. It changes from one part of the tape
to the next on a lot of these machines, even. Remember the whole
stability rests on the cassette shell and two little stamped-metal guides.

And to what extent is a mis-alignment built into heads that contain both
recording and playback coils?

Depends how well the heads were made. The folks at Nakamichi are better
at it than the folks at Tascam. Much of the reluctance of cassette
deck manufacturers to go to three-head designs was the difficulty of
aligning the two together.

Some of the comments here seem to indicate that a head with combined
record and playback coils can never be as perfectly aligned as a deck
with separate recording and playback heads. I can't see the logic in
that argument.

It's true, because as the head profile wears, the relative positions
change. Remember we're talking about tape with teeny-tiny tracks
running really slow here, so it doesn't take much change to have an
audible impact.

However, it's academic since there's no room to fit conventional
seperate heads into the shell... the shell design is the main limitation
here. The whole thing was intended as a cheap format for dictation
machines, it was never intended to do the kind of things people have
forced it into over the years.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

In article ,
D.M. Procida wrote:
Tape Guy wrote:

Some of the comments here seem to indicate that a head with combined
record and playback coils can never be as perfectly aligned as a deck
with separate recording and playback heads. I can't see the logic in
that argument.

The issue there is that different characteristics are required for play
and record heads. Combined record/playback heads are a compromise.

That's a third thing.

Your choices:

1. Separate record and play heads. Impossible for cassettes because of
the limited space in the shell opening. Gives you the ability to
adjust everything properly, although it requires doing the mechanical
alignment twice, obviously. This is how conventional studio machines
have worked for years.

2. A single record/play head. This means you lose confidence monitoring,
it means you are stuck with a gap that is really too wide for optimal
playback and too narrow for optimal recording. And it also means the
bias setting is a freaking nightmare of record, rewind, playback cycles.
Okay for cheap voice recording applications, not acceptable for anything
else because of the alignment difficulties.

3. The record and play heads in the same body. This is what most "3-head"
cassette decks do. Individual pole pieces for the record and play
sections, but mounted in the same package. This means your mechanical
alignment is only as good as the alignment of the pole pieces when the
assembly as made, since the two sides can't be adjusted individually.
It's pretty cheesy, but it gives you confidence monitoring and it fits
into the shell.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[D.M. Procida]

Scott Dorsey wrote:

The whole thing was intended as a cheap format for dictation
machines, it was never intended to do the kind of things people have
forced it into over the years.

And yet despite that, it worked pretty well, especially towards the end.
Sony's Walkman Pro hit a very useful compromise between affordability,
convenience and sound quality, as did some of the better Portastudio-
type machines, and both were used to record commercial albums.

Daniele
--
For sale: iBook G4 1.33MHz, 1.5GB RAM, super condition
http://search.ebay.co.uk/220368472534

[Scott Dorsey]

D.M. Procida wrote:
Scott Dorsey wrote:

The whole thing was intended as a cheap format for dictation
machines, it was never intended to do the kind of things people have
forced it into over the years.

And yet despite that, it worked pretty well, especially towards the end.
Sony's Walkman Pro hit a very useful compromise between affordability,
convenience and sound quality, as did some of the better Portastudio-
type machines, and both were used to record commercial albums.

Yes, it's something of a miracle that it worked as well as it did, and
you can thank a combination of the folks at Dolby who managed to adapt
their noise reduction system to a format with ragged low frequency
response and not have it mistrack severely, and the folks at Sony who
figured out how to make cheap tape guys that were mostly stable. Nobody
ever predicted it would wind up in as many different markets as it did.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Tape Guy]

Scott Dorsey wrote:

And yet despite that, it worked pretty well, especially towards
the end.

Yes, it's something of a miracle that it worked as well as it did,
and you can thank a combination of the folks at Dolby who managed
to adapt their noise reduction system to a format with ragged low
frequency response ...

I find that dbx gives better performance over dolby C on my Akai deck.
Was that a similar experience for Nakamichi owners?

[Scott Dorsey]

In article , Tape Guy wrote:
Scott Dorsey wrote:

And yet despite that, it worked pretty well, especially towards
the end.

Yes, it's something of a miracle that it worked as well as it did,
and you can thank a combination of the folks at Dolby who managed
to adapt their noise reduction system to a format with ragged low
frequency response ...

I find that dbx gives better performance over dolby C on my Akai deck.
Was that a similar experience for Nakamichi owners?

Is your Akai deck aligned for the tape you're using? Response problems
and level issues will cause both Dolby and dbx to pump, but they pump
differently in ways that aren't necessarily predictable.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[david correia]

In article ,
"Paul Stamler" wrote:

Except Nakamichi 3-head twin-capstan decks. They have ridges on either side
of the head assenbly which push the pressure pad away from the tape,
drastically cutting down the scrape flutter. They maintain tape tension with
the dual capstans.

Nobody else did this, because Nakamichi either bought the patent or obtained
an exclusive license on it from the folks who invented it (Eumig).

As a result, there are two categories of cassette decks: Nakamichi
three-head decks and everything else.



Didn't the 2 head Naks also push away the pressure pads?

One of the weird things with Naks is that the cassette recordings they
made would sound like crap on some brand's decks.

We had to pull a $1,500 Nak 680zx out of our control room and replace it
with a Sony 3 head deck back in the day, cuz we would run into the
occasional client that would remark about how crappy our cassette of
rough mixes from the last session sounded.

Thank you thank you for recording onto CD.

btw I booted that 680zx recently and it no longer plays back. The
transport seems fine and the heads are clean and demag-ed. The deck
doesn't have too many miles on it either. Any recommendations on where
to send it that doesn't charge 2 arms and a leg?

Man, whoever thought Nakamichi would ever not make or service cassette
decks ...




David Correia
www.Celebrationsound.com

[Keith.]

"Paul Stamler" wrote in message
...
"Tape Guy" wrote in message
...
Paul Stamler wrote:

I've got an Akai GX-A5X with Dolby B, C and DBX noise reduction,
and was wondering how such a deck compares to these so-called high-
end machines?

Badly.

each cassette incorporates a pressure pad to hold the tape against
the head. This adds a large amount of "scrape flutter", aka
"modulation noise" to the signal

Except Nakamichi 3-head twin-capstan decks.

That's cool.

How much time do you spend adjusting the play and record heads so they
track each other?

None; they're mounted in a common housing.

Akai's specs list the frequency response at 20 to 19khz +/-
3db using metal tape.

S/N listed as 60 db (metal) and 75-80 db with Dolby C. DBX
is listed as 115 db (dynamic range, not S/N).

And it'll sound terrible, too.

Sounds great. What's the Nakamichi's frequency response and S/N ratio?
Does it have DBX?

There are quite a few different models of Nakamichi, all with different
specs. However, the frequency responses and S/N ratios vary all over the
place, depending on what type of tape is used. Because of that, published
specs for cassette decks are not comparable with one another.

So far as I know, Nakamichi never made a model with dbx.

Wow and flutter: 0.05% (WRMS), 0.12% (DIN WTD).

Distortion: 0.65% (metal)

At what frequency, at what level, what kind of test? A single
distortion number, unfortunately, tells little or nothing.

Is Wow and flutter frequency dependent?

Wow and flutter are measurements of mechanical imperfections in the
transport, and have nothing to do with the frequency on the tape except
inasmuch as they frequency-modulate it.

What are the Nakamichi's numbers?

There are so many Naks that you'd be better off looking up a particular
model's numbers on the net. Bear in mind, though, that comparisons between
published frequency responses and S/N ratios are meaningless, and
wow/flutter numbers can be deceiving unless you know exactly how the
performance is being measured and weighted. That says, essentially, that
you can profitably compare wow/flutter numbers between the products of one
manufacturer, but not between different manufacturers.

Peace,
Paul

I have a product and test report on a Nak. 1000 in an Australian Stereo
Buyers guide for Cassette and Tape recorders if there is interest.
Keith.

[Paul Stamler[_2_]]

"david correia" wrote in message
...
In article ,
"Paul Stamler" wrote:

Except Nakamichi 3-head twin-capstan decks. They have ridges on either
side
of the head assenbly which push the pressure pad away from the tape,
drastically cutting down the scrape flutter. They maintain tape tension
with
the dual capstans.

Nobody else did this, because Nakamichi either bought the patent or
obtained
an exclusive license on it from the folks who invented it (Eumig).

As a result, there are two categories of cassette decks: Nakamichi
three-head decks and everything else.

Didn't the 2 head Naks also push away the pressure pads?

Nope -- at least, mine didn't, and some others I saw didn't.

Peace,
Paul

[Serge Auckland[_2_]]

"Paul Stamler" wrote in message
...
"david correia" wrote in message
...
In article ,
"Paul Stamler" wrote:

Except Nakamichi 3-head twin-capstan decks. They have ridges on either
side
of the head assenbly which push the pressure pad away from the tape,
drastically cutting down the scrape flutter. They maintain tape tension
with
the dual capstans.

Nobody else did this, because Nakamichi either bought the patent or
obtained
an exclusive license on it from the folks who invented it (Eumig).

As a result, there are two categories of cassette decks: Nakamichi
three-head decks and everything else.

Didn't the 2 head Naks also push away the pressure pads?

Nope -- at least, mine didn't, and some others I saw didn't.

Peace,
Paul


My Nakamichi 3 head dual-capstan (482Z) had physically separate record and
replay heads, each with their own adjustments for position and azimuth. The
erase head fitted into one of the other gaps in the cassette mechanism.
Aligning the tape mechanism was a bit of a bugger, but it seemed to be
stable once done. I used to align bias and sensitivity fairly often, as I
found that tape formulations were less than consistent batch to batch even
from the same manufacturer and type. I used Maxell metal tape at first, but
then changed to Taiyo Yuden (That's Tape) as I found that to be much more
consistent. The Nakamichi dual-capstan transport largely isolated the tape
from the cassette mechanism and with decent cassettes I had few mechanical
problems.

Nakamichi cassette recorders, especially with Dolby C produced results at
least as good as my Revox A77 provided recording levels were kept sensible,
which was possible with Dolby C. Tape costs and convenience was much better
with the Nak, and it got a lot of use before computer recording became
possible.

S.
--
http://audiopages.googlepages.com

[Serge Auckland[_2_]]

"Tape Guy" wrote in message ...
Scott Dorsey wrote:

And yet despite that, it worked pretty well, especially towards
the end.

Yes, it's something of a miracle that it worked as well as it did,
and you can thank a combination of the folks at Dolby who managed
to adapt their noise reduction system to a format with ragged low
frequency response ...

I find that dbx gives better performance over dolby C on my Akai deck.
Was that a similar experience for Nakamichi owners?

Dolby C worked extremely well on my Nak, (never tried DBX) but the machine
had to be aligned very accurately. Dolby C was in effects two Dolby B
processors in series, (the first Dolby C ics were just that) and
consequently errors in alignment were compounded. If you were using a
different tape to the one the machine was specifically aligned for, there
was no chance of Dolby C working correctly. I'm convinced that the reason so
many people didn't like Dolby C was that their machines were inadequately
aligned for it to work properly. There was also two Dolby C
implementations:- the first was two B processors in series, the later one
was a dedicated Dolby C ic. Unfortunately, the Dolby tracking between these
two implementations was different, and tapes made on one were out when
replayed on the other. My Nak 482Z had the earlier implementation, as did
the 3 head AIWA (can't remember the model No) of the same era. For Dolby C
to work properly, the record/replay gains had to be adjusted to within 1 dB,
and it just wasn't possible for that to be maintained in the field, with
consumers that would buy tapes by type (Ferric, Chrome, Metal) rather than
by specific formulation. I used to buy tapes in batches of 20 cassettes,
then realign for each batch. Tedious, and I wasn't sad to give up tape for
PC recording when that became available.

S.

--
http://audiopages.googlepages.com

[Arny Krueger]

"David Nebenzahl" wrote in message
.com...

Reread my post: I didn't claim that a Portastudio would "stand up" to
today's equipment. I said it was more than adequate for a recording made
more than a couple decades ago.

It's been over 25 years since the audio CD became the standard for sound
quality in a distribution format. Even 2 decades ago, the only justification
for the Portastudio was that it was the best we had at the time, not that it
was really adequate.

IME audio cassette is a horrible medium by modern standards. Anybody who
cares to dispute this need only post an Audio Rightmark test based on a
cassette record/play cycle that comes within an order of magnitude of the
2-in, 8-out digital audio interface that comes "free" on a modern PC system
board $75 such as the Asus M3A78-CM.

[Scott Dorsey]

david correia wrote:

One of the weird things with Naks is that the cassette recordings they
made would sound like crap on some brand's decks.

Yeah, the problem is that the Nak actually met the published specifications
for track width, while most other machines used reduced track widths to
allow more alignment slop. A lot of cassette decks couldn't hold height
alignment well enough to keep the second side audio from leaking into the
first, and the narrower track width helps that.

This gives you the SAME problem that we had before with 1/4" 2-track and
"European Stereo" formats... but the fringe effect problems are far,
far worse because the tracks are so small. Much of the high frequencies
are on the edge of the track... so if you have a Sony machine that IS
perfectly aligned for height and has the head in the center of the
track, you lose much of the high end.

We had to pull a $1,500 Nak 680zx out of our control room and replace it
with a Sony 3 head deck back in the day, cuz we would run into the
occasional client that would remark about how crappy our cassette of
rough mixes from the last session sounded.

We got the Tascam 122 for that. The capstan belt drive on those was
kind of ingenious and did actually bring flutter down somewhat, but
you had to replace the belt every couple of years and the eject button
would break every six months or so.

btw I booted that 680zx recently and it no longer plays back. The
transport seems fine and the heads are clean and demag-ed. The deck
doesn't have too many miles on it either. Any recommendations on where
to send it that doesn't charge 2 arms and a leg?

Steve Sank is still doing Nakamichi repair, and he used to be a warranty
repair center for those machines. My bet is that you have some relay and
switch contacts that need cleaning.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."