"Paul B" wrote in message
...
Thus spake Adrian C:
Ian Bell wrote:

I am surprised there has been so little development of cartridges
beyond the two basic magnetic types and good old ceramic. What about
an optical cartridge for example?

Ian

I've wondered about that! If you take the electronics that is
currently used to read where a microsoft optical mouse is on its
surface, give its microcontroller a short sharp reprogramming
session, and hang the whole caboodle off a linear tracking arm, it
would work?
University final year project for some lucky student reading this!

Remember the Finnial deck? HFN used to mention it as vapourware from time
to time. I think it finally got made. Laser optics to allow LP archiving
non-destructively but prone to noise unless used in a cleanroom IIRC &
with a truly cosmic price. As for linear tracking, aren't records mastered
on a swinging cutter arm?

My brother had a Miniconic strain gauge cartridge 30yrs ago - had a supply
but can remember too much about it. I suspect cartridge development more
or less stopped shortly after March 1983. With the average manufacturing
quality of vinyl, was not a huge surprise to me at least. Records weren't
thin enough not to support a warp & not thick enough not have one either.



Don't forget the defunct Weathers FM cartridge as well. As Arnie mentioned
the Japanese ELP company also manufacture optical vinyl players. I
understand they've progressed a lot from that poor Finnial deck but they are
still very expensive. If you contact the company they'll send a CD so you
can hear their vinyl replay :- http://www.elpj.com/about/index.html

Mike

In article , Mike Gilmour
wrote:


Don't forget the defunct Weathers FM cartridge as well.

Aha! I was just trying to recall the name and details of a cartridge that
IIRC used capacitance sensors and an AC signal to detect stylus movements.
Was that the "Weathers FM"? I can recall hearing mentions of this years
ago, but not any details.

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

"Ian Bell" wrote in message
news:4419d747.0@entanet...
Serge Auckland wrote:

My question is why Moving Coils should be thought to be better than
moving
magnets. I can think of several reasons why they should be worse, lower
compliance and higher mass, but not why they should be better.
Trackability should be better on a MM, as should record wear due to lower
tracking weights.


I am surprised there has been so little development of cartridges beyond
the
two basic magnetic types and good old ceramic. What about an optical
cartridge for example?

**Goodness me. There have been many different types of cartridges used over
the years, but, like internal combustion engines in automobiles, the
replacements don't offer the same advantages the tired old technology.


--
Trevor Wilson
www.rageaudio.com.au

On Thu, 16 Mar 2006 21:21:59 +0000, Ian Bell wrote:


Serge Auckland wrote:

My question is why Moving Coils should be thought to be better than moving
magnets. I can think of several reasons why they should be worse, lower
compliance and higher mass, but not why they should be better.
Trackability should be better on a MM, as should record wear due to lower
tracking weights.


I am surprised there has been so little development of cartridges beyond the
two basic magnetic types and good old ceramic. What about an optical
cartridge for example?

Are you talking about bouncing a laser off the record groove? It was a failu
it was too expensive and worked worse than traditional methods as it was best
at reading the crud in the groove instead of just pushing it aside.

AZ Nomad wrote:

On Thu, 16 Mar 2006 21:21:59 +0000, Ian Bell

I am surprised there has been so little development of cartridges beyond
the two basic magnetic types and good old ceramic. What about an optical
cartridge for example?

Are you talking about bouncing a laser off the record groove? It was a
failu it was too expensive and worked worse than traditional methods as
it was best at reading the crud in the groove instead of just pushing it
aside.

No I was thinking more of a small low mass pair of mirrors in place of the
MM for example with perhaps fibre optics to carry the data - no hum issues
for a start.

Ian

On Fri, 17 Mar 2006 08:06:08 +0000, Ian Bell wrote:


AZ Nomad wrote:

On Thu, 16 Mar 2006 21:21:59 +0000, Ian Bell

I am surprised there has been so little development of cartridges beyond
the two basic magnetic types and good old ceramic. What about an optical
cartridge for example?

Are you talking about bouncing a laser off the record groove? It was a
failu it was too expensive and worked worse than traditional methods as
it was best at reading the crud in the groove instead of just pushing it
aside.

No I was thinking more of a small low mass pair of mirrors in place of the
MM for example with perhaps fibre optics to carry the data - no hum issues
for a start.

No. You'd just have a 2lb brick with the electronics hanging off your
tonearm. :-)
Sure you could do better with today's microelectronics, but making custom
integrated circuits isn't a cheap endevor and I doubt any cartridge makers
forsee enough profits to cover development costs.

Besides, would a mirror really be lighter than a coil? If you wanted to
improve the noise problem, move the preamp into the turntable. The biggest
noise problem has always been the cables.

"AZ Nomad" wrote in message

On Fri, 17 Mar 2006 08:06:08 +0000, Ian Bell
wrote:


AZ Nomad wrote:

On Thu, 16 Mar 2006 21:21:59 +0000, Ian Bell


I am surprised there has been so little development of
cartridges beyond the two basic magnetic types and
good old ceramic. What about an optical cartridge for
example?

Are you talking about bouncing a laser off the record
groove? It was a failu it was too expensive and
worked worse than traditional methods as it was best at
reading the crud in the groove instead of just pushing
it aside.

No I was thinking more of a small low mass pair of
mirrors in place of the MM for example with perhaps
fibre optics to carry the data - no hum issues for a
start.

No. You'd just have a 2lb brick with the electronics
hanging off your tonearm. :-)

Not at all. It's painfully obvious to anybody conversant with modern
technology that such minimal electronics as would be required could be
extremely light.

Sure you could do better with today's microelectronics,
but making custom integrated circuits isn't a cheap
endevor and I doubt any cartridge makers forsee enough
profits to cover development costs.

There are zillions of kinds of optical transducers sitting on shelves all
over the world.

Besides, would a mirror really be lighter than a coil?

See my former comments about solid metalic magnets as opposed to tiny coils
of wire.

If you wanted to improve the noise problem, move the
preamp into the turntable. The biggest noise problem has
always been the cables.

Again, simply not true. The biggest noise problem has been stray field
pickup in magnetic cartridges by the coils. However this problem has been a
solved problem for about 35 years.

AZ Nomad wrote:

On Fri, 17 Mar 2006 08:06:08 +0000, Ian Bell

No I was thinking more of a small low mass pair of mirrors in place of the
MM for example with perhaps fibre optics to carry the data - no hum issues
for a start.

No. You'd just have a 2lb brick with the electronics hanging off your
tonearm. :-)
Sure you could do better with today's microelectronics, but making custom
integrated circuits isn't a cheap endevor and I doubt any cartridge makers
forsee enough profits to cover development costs.


Since when has cost been an issue for audiophiles ;-)

Besides, would a mirror really be lighter than a coil? If you wanted to
improve the noise problem, move the preamp into the turntable. The
biggest noise problem has always been the cables.

Coils have problems with rising impedance, parallel capacitance and
susceptibility to external radiation. Optics has none of these.

Ian

In article 441a6e41.0@entanet, Ian Bell wrote:
AZ Nomad wrote:

On Thu, 16 Mar 2006 21:21:59 +0000, Ian Bell

I am surprised there has been so little development of cartridges
beyond the two basic magnetic types and good old ceramic. What about
an optical cartridge for example?

Are you talking about bouncing a laser off the record groove? It was
a failu it was too expensive and worked worse than traditional
methods as it was best at reading the crud in the groove instead of
just pushing it aside.

No I was thinking more of a small low mass pair of mirrors in place of
the MM for example with perhaps fibre optics to carry the data - no hum
issues for a start.


IIRC Denon did this about 25 years ago, but the result was not a commercial
success.

People have tried various 'exotic' methods, but for whatever reasons, they
did not catch on. Bear in mind that audio is largely a 'fashion' industry
and people tend to consider what is recommened or repeatedly mentioned in
magazines.

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

Jim Lesurf wrote:

In article 441a6e41.0@entanet, Ian Bell wrote:

No I was thinking more of a small low mass pair of mirrors in place of
the MM for example with perhaps fibre optics to carry the data - no hum
issues for a start.


IIRC Denon did this about 25 years ago, but the result was not a
commercial success.


Optics were not common in consumer audio 25 years ago. A lot has changed
since then. Possibly time to look again.

Ian