In article , Trevor
Wilson wrote:


Similarly, frequency response plots of moving magnets and moving coils
don't show any particular benefit to the MC, nor does stereo
separation or harmonic and intermodulation distortion. So why *are*
MC cartridges throught to be better?

**Er, not quite. The FR plots of MC carts, in some cases, CAN be shown
to be superior. The reason, of course, is blindingly simple. It's all
about inductance. The inductance of (LOW OUTPUT) MC carts is very low,
indeed. This enables them to produce a very flat, very wide (up to
around 60kHz) frequency response, with a correspondingly superior rise
time.

The problem with this is that the mechanical resonances will still exist.
:-)

Also bear in mind that with a decent MM cartridge you can arrange the
loading to give quite a flat response if that is your concern. I've not
personally had any worries on that score with my own Shure V15/III...

Alas, magazines and makers now tend to avoid giving any useful data on
cartridges. Hence we usually can't now assess the level of compliance, tip
mass, etc, etc. Nor, indeed the levels of distortion.

My recollection was that MC's became 'flavour of the year' with some
subjective reviewers precisely because the ones in question did *not* have
a flat response, and they liked the changes, but then ascribed this to
'magic'... :-)


The real benefit of such a system is that LC resonance effects
are often well outside the audible range. This means that a low output
MC cart may exhibit a very flat phase response within the audio band.
This may not be the case with high output MC carts nor with some MM
carts.

For the record: Many, well designed, MM carts do not exhibit any
resonance problems without the audio band.

Indeed. Thus this isn't really a reason for arguing that MCs as a class of
object are 'better' to MMs as a class. :-)

The reality is that there will be 'good' and 'bad' examples in each class,
and a 'good' one in either may deliver excellent results.

FWIW I don't know of any MCs that can provide the same levels of tracking,
etc, of something like a Shure V15. But this may be because no-one for
years can be bothered to even consider such things in 'reviews'. sic

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 message
...
In article , Trevor
Wilson wrote:


Similarly, frequency response plots of moving magnets and moving coils
don't show any particular benefit to the MC, nor does stereo
separation or harmonic and intermodulation distortion. So why *are*
MC cartridges throught to be better?

**Er, not quite. The FR plots of MC carts, in some cases, CAN be shown
to be superior. The reason, of course, is blindingly simple. It's all
about inductance. The inductance of (LOW OUTPUT) MC carts is very low,
indeed. This enables them to produce a very flat, very wide (up to
around 60kHz) frequency response, with a correspondingly superior rise
time.

The problem with this is that the mechanical resonances will still exist.
:-)

Also bear in mind that with a decent MM cartridge you can arrange the
loading to give quite a flat response if that is your concern. I've not
personally had any worries on that score with my own Shure V15/III...

Alas, magazines and makers now tend to avoid giving any useful data on
cartridges. Hence we usually can't now assess the level of compliance, tip
mass, etc, etc. Nor, indeed the levels of distortion.

My recollection was that MC's became 'flavour of the year' with some
subjective reviewers precisely because the ones in question did *not* have
a flat response, and they liked the changes, but then ascribed this to
'magic'... :-)



More and more these days, I'm finding there comes a time when it pays not to
read the ingredients when you are eating something.

Without any knowledge of the 'claimed specifications' of the kit in use, I
did indeed experience some 'magical' qualities with a number of 'nothing
special' old (freebie) MC carts a while back - *all* of which I would have
expected to be some way off claimed, original performance specifications,
due to age and infirmity.

The MC10 I mentioned in an earlier post actually had quite a badly bent
cantilever which had obviously had one or two attempts to straighten it
(including 2 attempts by me) which eventually slowly sank to its death,
still sounding quite unutterably *sublime* until the bodywork was actually
riding the vinyl! It was almost a tragical experience!! ('Sublime = 'sweet,
delicate, sonorous, detailed' and *captivating' in this instance...)

Not too 'scientific' I know, but there is more in it for me than just the
numbers. (Perhaps I'm more of a 'mystic' myself than I would care to admit!!
;-)

"Jim Lesurf" wrote in message
...
In article , Trevor
Wilson wrote:


Similarly, frequency response plots of moving magnets and moving coils
don't show any particular benefit to the MC, nor does stereo
separation or harmonic and intermodulation distortion. So why *are*
MC cartridges throught to be better?

**Er, not quite. The FR plots of MC carts, in some cases, CAN be shown
to be superior. The reason, of course, is blindingly simple. It's all
about inductance. The inductance of (LOW OUTPUT) MC carts is very low,
indeed. This enables them to produce a very flat, very wide (up to
around 60kHz) frequency response, with a correspondingly superior rise
time.

The problem with this is that the mechanical resonances will still exist.
:-)

**True. Some manufacturers go to extreme lengths to deal with such problems.


Also bear in mind that with a decent MM cartridge you can arrange the
loading to give quite a flat response if that is your concern. I've not
personally had any worries on that score with my own Shure V15/III...

**And one of my favourites happens to be the V15 VMR. An extremely neutral
cartridge. In fact, I did a recording of an LP from the V15 VMR onto a CD
and compared it to the CD, in uncontrolled conditions, but, apart from the
obvious surface noise, the result was bloody hard to pick.


Alas, magazines and makers now tend to avoid giving any useful data on
cartridges. Hence we usually can't now assess the level of compliance, tip
mass, etc, etc. Nor, indeed the levels of distortion.

My recollection was that MC's became 'flavour of the year' with some
subjective reviewers precisely because the ones in question did *not* have
a flat response, and they liked the changes, but then ascribed this to
'magic'... :-)

**Not necessarily, but maybe. Certainly, some MC carts, like the Linn Asak
had an appallingly bad response, which was preferred by many listeners. Same
deal with the onld Talisman S (sapphire cantilever). Ironically, the cheaper
Talisman B (Boron cantilever) was a more neutral cartidge. Not only was the
Talisman B very flat accross the audile range, but sample to sample
variations was very impressive. Best of all (IMO) was the fabulously neutral
Dynavector 17DII. Not only does/did the 17DII exhibit a very neutral
response, but it can do so over a wide temperature range (unlike almost
every other cartridge). Try your V15III in sub 10oC temps and get back to
me. The rubber suspension hardens, along with the sound. Not so the
Dynavector.



The real benefit of such a system is that LC resonance effects
are often well outside the audible range. This means that a low output
MC cart may exhibit a very flat phase response within the audio band.
This may not be the case with high output MC carts nor with some MM
carts.

For the record: Many, well designed, MM carts do not exhibit any
resonance problems without the audio band.

Indeed. Thus this isn't really a reason for arguing that MCs as a class of
object are 'better' to MMs as a class. :-)

**Perhaps. The fact that MCs can be made to operate well in the many tens of
kHz means their phase repsonse is very good in the audio range.


The reality is that there will be 'good' and 'bad' examples in each class,
and a 'good' one in either may deliver excellent results.

**Agreed. In fact, for an easy to live with, easy to tolerate (arm-wise) and
very accurate cart, it is hard to go past the (now deleted) V15 VMR.


FWIW I don't know of any MCs that can provide the same levels of tracking,
etc, of something like a Shure V15. But this may be because no-one for
years can be bothered to even consider such things in 'reviews'. sic

**Yep.


--
Trevor Wilson
www.rageaudio.com.au

"Trevor Wilson" wrote


**And one of my favourites happens to be the V15 VMR. An extremely neutral
cartridge. In fact, I did a recording of an LP from the V15 VMR onto a CD
and compared it to the CD, in uncontrolled conditions, but, apart from the
obvious surface noise, the result was bloody hard to pick.


Yep, been there, done that a number of times. The 'light touch' of the V15
Mk V xMR duplicates CD very well. The best and easiest comparison to make is
Brothers In Arms. I can set both running and switch between them - generally
listeners do not know which is which until there's a pop or a fart from the
LP (which is actually very quiet)....





Try your V15III in sub 10oC temps


???



**Perhaps. The fact that MCs can be made to operate well in the many tens
of kHz means their phase repsonse is very good in the audio range.


HFW Sept 2004 (re. MC carts):

"To minimise moving mass (tip mass) the signal coils must be light and
small, so they have few turns and give little output. Generator losses are
minimal though and frequency response flat as a result. Sound quality gains
in terms of transparency and detail, providing the stylus is up to the job
and damping sufficient to control tip mass resonance.

And:

"Frequency response can far exceed that of CD, by the way."

;-)


**Agreed. In fact, for an easy to live with, easy to tolerate (arm-wise)
and very accurate cart, it is hard to go past the (now deleted) V15 VMR.


Except that it's a bit too 'polite' (bass-light) to do a convincing *piano*
(lower register)....

In article , Keith G
wrote:

"Trevor Wilson" wrote


Try your V15III in sub 10oC temps


???

The V15/III carts (and some other Shures IIRC) have a suspension with a
compliance that varies quite markedly with temperature. Thus they work well
to spec at 20 degC, but if you have a colder room, they may well not! IIRC
this is because they use a 'rubber' gasket that becomes stiffer as the
temperature falls.

Fortunately, despite the current leaky roof, I can keep the room
temperature comfortable when listening to music - both for my benefit, and
for the audio equipment's. :-)


**Agreed. In fact, for an easy to live with, easy to tolerate
(arm-wise) and very accurate cart, it is hard to go past the (now
deleted) V15 VMR.


Except that it's a bit too 'polite' (bass-light) to do a convincing
*piano* (lower register)....

Depends on the loading and the arm mass, etc. In general, I worry more
about the speakers and the room acoustics for affecting this.

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

On Thu, 16 Mar 2006 19:08:27 -0000, "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.

The quality of the stylus may be better on an expensive cartridge, but in my
own case, I have a Goldring 1042 and a Shure V15IIIMR. The stylus in the
Goldring is the Gyger S, I understand similar to the VdH, the Shure MR is a
Namiki profile, so they are as good as anything available on a moving coil.

Similarly, frequency response plots of moving magnets and moving coils don't
show any particular benefit to the MC, nor does stereo separation or
harmonic and intermodulation distortion. So why *are* MC cartridges throught
to be better?

If anyone knows of any good engineering reasons why this should be so, I
would be most interested to hear.

The only vaguely convincing explanation that I've heard is that MCs
can use less damping of the stylus assembly. Theoretically this
should allow better trackability at mid frequencies. I also have vague
recollections that the cantilever can more easily be made shorter,
which would help in keeping the effective tip mass down, which should
give better HF trackability. (Compliance only needs to be more than
about 10-12c.u. to track all records)

Not being a member of the MC owners club, I don't know if these
theories have any validity.

Bill

"Bill Taylor" wrote in message
...
On Thu, 16 Mar 2006 19:08:27 -0000, "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.

The quality of the stylus may be better on an expensive cartridge, but in
my
own case, I have a Goldring 1042 and a Shure V15IIIMR. The stylus in the
Goldring is the Gyger S, I understand similar to the VdH, the Shure MR is
a
Namiki profile, so they are as good as anything available on a moving
coil.

Similarly, frequency response plots of moving magnets and moving coils
don't
show any particular benefit to the MC, nor does stereo separation or
harmonic and intermodulation distortion. So why *are* MC cartridges
throught
to be better?

If anyone knows of any good engineering reasons why this should be so, I
would be most interested to hear.

The only vaguely convincing explanation that I've heard is that MCs
can use less damping of the stylus assembly. Theoretically this
should allow better trackability at mid frequencies. I also have vague
recollections that the cantilever can more easily be made shorter,
which would help in keeping the effective tip mass down, which should
give better HF trackability. (Compliance only needs to be more than
about 10-12c.u. to track all records)

Not being a member of the MC owners club, I don't know if these
theories have any validity.

Bill

Interesting theories. Can you tell me a bit more as to why a compliance of
10-12cu is sufficient for all records? Interesting that in vinyl's heyday,
some cartridges were providing 30-40 cu. It could be a marketing exercise
rather than having a sound engineering reason for it, but it would be useful
to know why such high compliances are not necessary.

Thanks

S.

On Thu, 16 Mar 2006 23:23:34 -0000, "Serge Auckland"
wrote:


"Bill Taylor" wrote in message
...
On Thu, 16 Mar 2006 19:08:27 -0000, "Serge Auckland"
wrote:


Similarly, frequency response plots of moving magnets and moving coils
don't
show any particular benefit to the MC, nor does stereo separation or
harmonic and intermodulation distortion. So why *are* MC cartridges
throught
to be better?

If anyone knows of any good engineering reasons why this should be so, I
would be most interested to hear.

The only vaguely convincing explanation that I've heard is that MCs
can use less damping of the stylus assembly. Theoretically this
should allow better trackability at mid frequencies. I also have vague
recollections that the cantilever can more easily be made shorter,
which would help in keeping the effective tip mass down, which should
give better HF trackability. (Compliance only needs to be more than
about 10-12c.u. to track all records)

Not being a member of the MC owners club, I don't know if these
theories have any validity.

Bill

Interesting theories. Can you tell me a bit more as to why a compliance of
10-12cu is sufficient for all records? Interesting that in vinyl's heyday,
some cartridges were providing 30-40 cu. It could be a marketing exercise
rather than having a sound engineering reason for it, but it would be useful
to know why such high compliances are not necessary.


According to J Walton in "Pickups - The Key to Hi Fi" (published 1968,
but the physics haven't changed): the maximum excursion on an LP is
about .005cm, "if compliance were the only factor involved a
compliance of 2 c.u. is quite sufficient to track the largest stereo
amplitude of .005 cm at 3 gm tracking weight". It's possible that a
small number of modern LPs have slightly higher excursions, and
tracking weights are a bit lower, so a slightly higher compliance is
needed, but not that much higher.

The very high compliances of the 70s were very much a marketing
excercise. The other important factor with compliance is the LF
resonance with the cartridge/arm mass. The ideal resonant frequency is
about 10-15 Hz, any lower than that and the cartridge system is liable
to become unstable and skip grooves with the slightest disturbance,
and the oscillations caused by these disturbances produce very audible
wow and tracking force variations. Some of the high compliance
cartridges needed a negative mass arm in order to get the LF resonance
up to a reasonable frequency.

I recently changed my turntable. The only reasonably priced one that I
felt that I could trust was the Technics DJ turntable (basically a
1970s HiFi turntable with a speed control). The supplied arm has
quite a high effective mass and with the Shure V15-V that I had to buy
as well the LF resonance is plainly much to low, this cartridge has a
more reasonable compliance of about 23c.u., but it is still too high.
Forunately the Shure damper more or less controls the resonance.

There is another advantage of MCs that was certainly true in the 60s
and 70s. It is much easier to create a large magnetic field with a big
static magnet in the body of the cartridge than it is with a small
magnet on the end of the cantilever, so in the days of less effective
magnets it would probably be possible to keep the effective tip mass
lower with MC rather than MM cartridges.

Bill

"Bill Taylor" wrote in message
...
On Thu, 16 Mar 2006 23:23:34 -0000, "Serge Auckland"
wrote:


"Bill Taylor" wrote in message
...
On Thu, 16 Mar 2006 19:08:27 -0000, "Serge Auckland"
wrote:



The only vaguely convincing explanation that I've heard is that MCs
can use less damping of the stylus assembly. Theoretically this
should allow better trackability at mid frequencies. I also have vague
recollections that the cantilever can more easily be made shorter,
which would help in keeping the effective tip mass down, which should
give better HF trackability. (Compliance only needs to be more than
about 10-12c.u. to track all records)

Bill

Interesting theories. Can you tell me a bit more as to why a compliance of
10-12cu is sufficient for all records? Interesting that in vinyl's heyday,
some cartridges were providing 30-40 cu. It could be a marketing exercise
rather than having a sound engineering reason for it, but it would be
useful
to know why such high compliances are not necessary.


According to J Walton in "Pickups - The Key to Hi Fi" (published 1968,
but the physics haven't changed): the maximum excursion on an LP is
about .005cm, "if compliance were the only factor involved a
compliance of 2 c.u. is quite sufficient to track the largest stereo
amplitude of .005 cm at 3 gm tracking weight". It's possible that a
small number of modern LPs have slightly higher excursions, and
tracking weights are a bit lower, so a slightly higher compliance is
needed, but not that much higher.

Thanks for the reference. I'll try and find one if possible.

The very high compliances of the 70s were very much a marketing
excercise. The other important factor with compliance is the LF
resonance with the cartridge/arm mass. The ideal resonant frequency is
about 10-15 Hz, any lower than that and the cartridge system is liable
to become unstable and skip grooves with the slightest disturbance,
and the oscillations caused by these disturbances produce very audible
wow and tracking force variations. Some of the high compliance
cartridges needed a negative mass arm in order to get the LF resonance
up to a reasonable frequency.

Yes, remember the ADC25? Compliance 50 units, cartridge mass 8.3 gm. Needed
a 0 mass arm!

"Bill Taylor" wrote in message
...
On Thu, 16 Mar 2006 23:23:34 -0000, "Serge Auckland"
wrote:


"Bill Taylor" wrote in message
...
On Thu, 16 Mar 2006 19:08:27 -0000, "Serge Auckland"
wrote:



The only vaguely convincing explanation that I've heard is that MCs
can use less damping of the stylus assembly. Theoretically this
should allow better trackability at mid frequencies. I also have vague
recollections that the cantilever can more easily be made shorter,
which would help in keeping the effective tip mass down, which should
give better HF trackability. (Compliance only needs to be more than
about 10-12c.u. to track all records)

Bill

Interesting theories. Can you tell me a bit more as to why a compliance of
10-12cu is sufficient for all records? Interesting that in vinyl's heyday,
some cartridges were providing 30-40 cu. It could be a marketing exercise
rather than having a sound engineering reason for it, but it would be
useful
to know why such high compliances are not necessary.


According to J Walton in "Pickups - The Key to Hi Fi" (published 1968,
but the physics haven't changed): the maximum excursion on an LP is
about .005cm, "if compliance were the only factor involved a
compliance of 2 c.u. is quite sufficient to track the largest stereo
amplitude of .005 cm at 3 gm tracking weight". It's possible that a
small number of modern LPs have slightly higher excursions, and
tracking weights are a bit lower, so a slightly higher compliance is
needed, but not that much higher.

Thanks for the reference. I'll try and find one if possible.

The very high compliances of the 70s were very much a marketing
excercise. The other important factor with compliance is the LF
resonance with the cartridge/arm mass. The ideal resonant frequency is
about 10-15 Hz, any lower than that and the cartridge system is liable
to become unstable and skip grooves with the slightest disturbance,
and the oscillations caused by these disturbances produce very audible
wow and tracking force variations. Some of the high compliance
cartridges needed a negative mass arm in order to get the LF resonance
up to a reasonable frequency.

Yes, remember the ADC25? Compliance 50 units, cartridge mass 8.3 gm. Needed
a 0 mass arm!