In article ,
Jim Lesurf wrote:
In article , Dave Plowman (News)
wrote:
The Compact Cassette was introduced as a mono format for dictation
machines, etc. Philips were sensible enough to allow it to be used
under license but free of charge. But did retain a degree of control
over the basics.

I'm not sure if this included the use of Dolby B or not. But did over
the basics like speed.

IIRC They mandated aspects like the physical dimensions (inc. things like
track widths and spacings), but I'm not sure about which 'electronic'
details they might have defined or limited.

Yes. But then they probably couldn't guess what might be developed down
the line. Like Dolby B and much better tape.

They did try to flog their own 'noise reduction' (DNS?) system which was
single-ended. But I don't recall that they could (or attempted to) block
or control the adoption of Dolby. If nothing else, they couldn't have
stopped anyone from buying a Bolby adaptor box, anyway! Given how good
Dolby was they probably twigged quite quickly it would be good for
sales, and hence their own deck/cassette royalties!

Ah - of course. DNS.

I've a feeling that the majority of music cassettes with Dolby B were
actually listened to - in the car etc - with Dolby switched off. ;-)

--
*Why do the two "sanction"s (noun and verb) mean opposites?*

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

On 28/01/2017 11:37, Dave Plowman (News) wrote:

I've a feeling that the majority of music cassettes with Dolby B were
actually listened to - in the car etc - with Dolby switched off. ;-)

I once had a car with both Dolby B and Dolby C!

--
Eiron.

In article ,
Eiron wrote:
On 28/01/2017 11:37, Dave Plowman (News) wrote:

I've a feeling that the majority of music cassettes with Dolby B were
actually listened to - in the car etc - with Dolby switched off. ;-)

I once had a car with both Dolby B and Dolby C!

Posh. ;-)

The last generation of analogue 1/4" pro tape machines I saw had Dolby SR.
I was very impressed with that. In practice, not far short of digital
noise wise.

--
*Everyone has a photographic memory. Some just don't have film*

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

Jim Lesurf:
In article , Dave Plowman (News)
wrote:
The Compact Cassette was introduced as a mono format for dictation
machines, etc. Philips were sensible enough to allow it to be used
under
license but free of charge. But did retain a degree of control over
the
basics.

I'm not sure if this included the use of Dolby B or not. But did
over
the basics like speed.

IIRC They mandated aspects like the physical dimensions (inc. things
like
track widths and spacings), but I'm not sure about which 'electronic'
details they might have defined or limited.

They did try to flog their own 'noise reduction' (DNS?) system which
was
single-ended. But I don't recall that they could (or attempted to)
block or
control the adoption of Dolby. If nothing else, they couldn't have
stopped
anyone from buying a Bolby adaptor box, anyway! Given how good Dolby
was
they probably twigged quite quickly it would be good for sales, and
hence
their own deck/cassette royalties!

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics
http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

It wasn't DNS but DNL for Dynamic Noise Limiting - it was single ended
(didn't do anyhting during recording) and didn't work that well
(according to my ears). You could use it with Dolby and get a further
improvement to signal to noise ratio and one or two cassetted decs
allowed this - it didn't catch on so I assume that my impression was not
untypical.

http://audiotools.com/noise.html

https://www.hifiengine.com/manual_li.../ad-1800.shtml

MK

In article , Michael Kellett
wrote:
Jim Lesurf:


They did try to flog their own 'noise reduction' (DNS?) system which
was
single-ended.


It wasn't DNS but DNL for Dynamic Noise Limiting - it was single ended
(didn't do anyhting during recording) and didn't work that well
(according to my ears). You could use it with Dolby and get a further
improvement to signal to noise ratio and one or two cassetted decs
allowed this - it didn't catch on so I assume that my impression was not
untypical.

Thanks. I couldn't recall the precise term. Too long ago! :-)

I never heard it in practice. It had essentially vanished before I got
around to buying a cassette deck. But I'm not amazed it didn't catch on.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

"Dave Plowman (News)" wrote in message
...
The last generation of analogue 1/4" pro tape machines I saw had Dolby SR.
I was very impressed with that. In practice, not far short of digital
noise wise.

And still in demand. The wide-frame version of the Studer A80/24track
has a compartment under the transport into which an SR rack fitted nicely.

Many producers like to have their project recorded on analogue multitrack
and then transferred to a DAW for editing, post and mixing - the best of
both worlds. Once transferred to and backed-up, the analogue tapes are
bulk-erased and used again. Usually there is only a nominal charge for
the use of the tape.

Iain

"Jim Lesurf" wrote in message
...
In article , Michael Kellett
wrote:
Jim Lesurf:


They did try to flog their own 'noise reduction' (DNS?) system which
was
single-ended.


It wasn't DNS but DNL for Dynamic Noise Limiting - it was single ended
(didn't do anyhting during recording) and didn't work that well
(according to my ears). You could use it with Dolby and get a further
improvement to signal to noise ratio and one or two cassetted decs
allowed this - it didn't catch on so I assume that my impression was not
untypical.

Thanks. I couldn't recall the precise term. Too long ago! :-)

I never heard it in practice. It had essentially vanished before I got
around to buying a cassette deck. But I'm not amazed it didn't catch on.


Prerecorded cassettes were always something of a compromise
(high-speed loop-bin duplication) but towards the end of that era,
chrome tape with Dolby B was starting to sound pretty good. RCA
issued some classical titles on chrome, as an in-car boxed set.
They were well received, and probably convinced people to buy
the vinyl and listen properly at home when then could. Just as people
nowadays who download and learn to like something may order the CD.
Ching,ching (cash register rings up a double sale:-)

Iain

In article , Iain Churches
wrote:
Prerecorded cassettes were always something of a compromise (high-speed
loop-bin duplication) but towards the end of that era, chrome tape with
Dolby B was starting to sound pretty good.

That reminds me that there was at least one company who did 'real time'
Cassette duplications for the sake of sound quality. I can't now recall
their name(s), though. Something like "White(something" perhaps was one of
them.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

"Jim Lesurf" wrote in message
...
In article , Iain Churches
wrote:
Prerecorded cassettes were always something of a compromise (high-speed
loop-bin duplication) but towards the end of that era, chrome tape with
Dolby B was starting to sound pretty good.

That reminds me that there was at least one company who did 'real time'
Cassette duplications for the sake of sound quality. I can't now recall
their name(s), though. Something like "White(something" perhaps was one of
them.

There were probably many. One I know of in North
London was called "SuperCassette" (original, eh?)
They had a large room with dexion shelves floor to
ceiling with two or three realtime high-end cassette
recorders (Nakamichi or something similar) on each
shelf. Each "aisle" was fed by its own "master
recorder" (Revox A77) with a studio copy of the
master running at 15 ips. The cassettes sounded
quite good!

Iain

On Sun, 12 Feb 2017 23:35:04 +0200, Iain Churches wrote:

"Jim Lesurf" wrote in message
...
In article , Iain Churches
wrote:
Prerecorded cassettes were always something of a compromise
(high-speed loop-bin duplication) but towards the end of that era,
chrome tape with Dolby B was starting to sound pretty good.

That reminds me that there was at least one company who did 'real time'
Cassette duplications for the sake of sound quality. I can't now recall
their name(s), though. Something like "White(something" perhaps was one
of them.

There were probably many. One I know of in North London was called
"SuperCassette" (original, eh?) They had a large room with dexion
shelves floor to ceiling with two or three realtime high-end cassette
recorders (Nakamichi or something similar) on each shelf. Each "aisle"
was fed by its own "master recorder" (Revox A77) with a studio copy of
the master running at 15 ips. The cassettes sounded quite good!


I wonder, seeing as they were going to such an extreme, whether they
also ran the master and slaves in reverse to mitigate the phase delay
'distortion' effect on low frequency square wave test signals which made
such test signals look like triangle waves on playback when viewed on an
oscilloscope, or did they just accept that despite this very visible
departure from the original waveshape, no one could distinguish the
direct versus the phase distorted magnetic recording playback by ear
alone anyway? :-)

--
Johnny B Good