In message , Don Pearce
writes
On Thu, 19 Oct 2006 10:42:37 +0100, "Keith G"
wrote:


"Nick Gorham" wrote

Actually, the rolled-off bass may be to do with the amplifier. Many
phono stages incorporate a high-pass filter to remove subsonic bass.
This can help power handling by preventing the speakers from flapping
with unheard sounds.


'E's not daft that Don....!! ;-)



d


Which phono was that Keith, I must admit, that curve looks very like the
spice model I have for the WAD phono.


That's the little Pioneer SA-510's own onboard (SS) phono stage - my
'computer setup'..!!



I must get a new test disk, I have found traces I did several years ago,
with different arm/cartridge/deck and phono stage that still shows the HF
inbalance that the response I posted shows.



The HFS75 disk I have is the most *offcentre* pressing I have ever seen and
thus came to me virtually unused!!





The latest V15 plot is here now, with the rumble filter gone. It has
flattened out all the lower mid bounciness, although there is still
evidence of a low end cutoff - just not at frequencies anyone is going
to worry about.

The top end is interesting - it has grown a peak which I think I can
explain. I believe that removing the rumble filter has changed the
capacitive loading on the cartridge considerably, and what we are
seeing is what I predicted from my maths - extreme sensitivity of the
top end to resonance from capacitive loading. I produced plots that
looked exactly like this in my musings. This is all very interesting.

The general dropoff above 1kHz looks almost like a mis-set tone
control.

http://81.174.169.10/odds/dspkr/v15pink3.gif

Depending on by how much the capacitance has changed, I would say that
the V15-5 was the least sensitive of the V15's to capacitance loading.
The V15-3 being the most sensitive!
--
Kevin Seal
F800ST
{kevin at the hyphen seal hyphen house dot freeserve dot co dot uk}

On Thu, 19 Oct 2006 23:25:17 +0100, Kevin Seal wrote:

In message , Don Pearce
writes
On Thu, 19 Oct 2006 10:42:37 +0100, "Keith G"
wrote:


"Nick Gorham" wrote

Actually, the rolled-off bass may be to do with the amplifier. Many
phono stages incorporate a high-pass filter to remove subsonic bass.
This can help power handling by preventing the speakers from flapping
with unheard sounds.


'E's not daft that Don....!! ;-)



d


Which phono was that Keith, I must admit, that curve looks very like the
spice model I have for the WAD phono.


That's the little Pioneer SA-510's own onboard (SS) phono stage - my
'computer setup'..!!



I must get a new test disk, I have found traces I did several years ago,
with different arm/cartridge/deck and phono stage that still shows the HF
inbalance that the response I posted shows.



The HFS75 disk I have is the most *offcentre* pressing I have ever seen and
thus came to me virtually unused!!





The latest V15 plot is here now, with the rumble filter gone. It has
flattened out all the lower mid bounciness, although there is still
evidence of a low end cutoff - just not at frequencies anyone is going
to worry about.

The top end is interesting - it has grown a peak which I think I can
explain. I believe that removing the rumble filter has changed the
capacitive loading on the cartridge considerably, and what we are
seeing is what I predicted from my maths - extreme sensitivity of the
top end to resonance from capacitive loading. I produced plots that
looked exactly like this in my musings. This is all very interesting.

The general dropoff above 1kHz looks almost like a mis-set tone
control.

http://81.174.169.10/odds/dspkr/v15pink3.gif

Depending on by how much the capacitance has changed, I would say that
the V15-5 was the least sensitive of the V15's to capacitance loading.
The V15-3 being the most sensitive!

The numbers don't support you here. The V15-3 had an inductance of
500mH, and the V15-5 was much higher at 720mH. That would make the 5
far more sensitive to things capacitive than the other.

d

--
Pearce Consulting
http://www.pearce.uk.com

--
Posted via a free Usenet account from http://www.teranews.com

In message , Don Pearce
writes
On Thu, 19 Oct 2006 23:25:17 +0100, Kevin Seal wrote:

snip.

http://81.174.169.10/odds/dspkr/v15pink3.gif

Depending on by how much the capacitance has changed, I would say that
the V15-5 was the least sensitive of the V15's to capacitance loading.
The V15-3 being the most sensitive!

The numbers don't support you here. The V15-3 had an inductance of
500mH, and the V15-5 was much higher at 720mH. That would make the 5
far more sensitive to things capacitive than the other.

From the Shure website.....

V15-V
Inductance 330mH
DC resistance 815 Ohms

V15-3
Inductance 500mH
DC resistance 1350 Ohms.

With regards to Arny's post, the V15-3's response would be affected from
about 1kHz upwards if loaded with only half it's required capacitance.
The response would droop from 1kHz then rise to a peak at around 8 to
10kHz, then drop off again as it approached 20Khz.
--
Kevin Seal
F800ST
{kevin at the hyphen seal hyphen house dot freeserve dot co dot uk}

On Fri, 20 Oct 2006 19:41:05 +0100, Kevin Seal wrote:

In message , Don Pearce
writes
On Thu, 19 Oct 2006 23:25:17 +0100, Kevin Seal wrote:

snip.

http://81.174.169.10/odds/dspkr/v15pink3.gif

Depending on by how much the capacitance has changed, I would say that
the V15-5 was the least sensitive of the V15's to capacitance loading.
The V15-3 being the most sensitive!

The numbers don't support you here. The V15-3 had an inductance of
500mH, and the V15-5 was much higher at 720mH. That would make the 5
far more sensitive to things capacitive than the other.

From the Shure website.....

V15-V
Inductance 330mH
DC resistance 815 Ohms

V15-3
Inductance 500mH
DC resistance 1350 Ohms.

With regards to Arny's post, the V15-3's response would be affected from
about 1kHz upwards if loaded with only half it's required capacitance.
The response would droop from 1kHz then rise to a peak at around 8 to
10kHz, then drop off again as it approached 20Khz.

I've done the maths for V15-III and V15-V using these numbers, and the
results are here. Note that they are relative only, and do not reflect
the actual flatness of the cartridge, which will also depend on
mechanical factors.

http://81.174.169.10/odds/v15iii/cartridge.html
http://81.174.169.10/odds/v15v/cartridge.html

The V15-V appears to be more heavily influenced by the load
capacitance.

d

--
Pearce Consulting
http://www.pearce.uk.com

--
Posted via a free Usenet account from http://www.teranews.com

"Don Pearce" wrote in message

On Fri, 20 Oct 2006 19:41:05 +0100, Kevin Seal
wrote:

In message , Don
Pearce writes
On Thu, 19 Oct 2006 23:25:17 +0100, Kevin Seal
wrote:

snip.

http://81.174.169.10/odds/dspkr/v15pink3.gif

Depending on by how much the capacitance has changed,
I would say that the V15-5 was the least sensitive of
the V15's to capacitance loading. The V15-3 being the
most sensitive!

The numbers don't support you here. The V15-3 had an
inductance of 500mH, and the V15-5 was much higher at
720mH. That would make the 5 far more sensitive to
things capacitive than the other.

From the Shure website.....

V15-V
Inductance 330mH
DC resistance 815 Ohms

V15-3
Inductance 500mH
DC resistance 1350 Ohms.

With regards to Arny's post, the V15-3's response would
be affected from about 1kHz upwards if loaded with only
half it's required capacitance. The response would droop
from 1kHz then rise to a peak at around 8 to 10kHz, then
drop off again as it approached 20Khz.

I've done the maths for V15-III and V15-V using these
numbers, and the results are here. Note that they are
relative only, and do not reflect the actual flatness of
the cartridge, which will also depend on mechanical
factors.

http://81.174.169.10/odds/v15iii/cartridge.html
http://81.174.169.10/odds/v15v/cartridge.html

The V15-V appears to be more heavily influenced by the
load capacitance.

These curves look a lot like practical reality as I saw it, back in the days
when vinyl was all we had.

I would suggest that the performance of the mechanical system was not very
much influenced by the cartrdige loading at that these curves pretty well
added to its response a linear fashion like cascaded amplifier stages.

In message , Arny Krueger
writes
"Don Pearce" wrote in message

On Fri, 20 Oct 2006 19:41:05 +0100, Kevin Seal
wrote:

In message , Don
Pearce writes
On Thu, 19 Oct 2006 23:25:17 +0100, Kevin Seal
wrote:

snip.

http://81.174.169.10/odds/dspkr/v15pink3.gif

Depending on by how much the capacitance has changed,
I would say that the V15-5 was the least sensitive of
the V15's to capacitance loading. The V15-3 being the
most sensitive!

The numbers don't support you here. The V15-3 had an
inductance of 500mH, and the V15-5 was much higher at
720mH. That would make the 5 far more sensitive to
things capacitive than the other.

From the Shure website.....

V15-V
Inductance 330mH
DC resistance 815 Ohms

V15-3
Inductance 500mH
DC resistance 1350 Ohms.

With regards to Arny's post, the V15-3's response would
be affected from about 1kHz upwards if loaded with only
half it's required capacitance. The response would droop
from 1kHz then rise to a peak at around 8 to 10kHz, then
drop off again as it approached 20Khz.

I've done the maths for V15-III and V15-V using these
numbers, and the results are here. Note that they are
relative only, and do not reflect the actual flatness of
the cartridge, which will also depend on mechanical
factors.

http://81.174.169.10/odds/v15iii/cartridge.html
http://81.174.169.10/odds/v15v/cartridge.html

The V15-V appears to be more heavily influenced by the
load capacitance.

These curves look a lot like practical reality as I saw it, back in the days
when vinyl was all we had.

The top end is typical shape, but in reality, there should be a sag in
the mid range.

I would suggest that the performance of the mechanical system was not very
much influenced by the cartrdige loading at that these curves pretty well
added to its response a linear fashion like cascaded amplifier stages.

I'm sorry Arny, I've read it three times now, but I still am not sure
what you are saying!
--
Kevin Seal
F800ST
{kevin at the hyphen seal hyphen house dot freeserve dot co dot uk}

"Kevin Seal" wrote in message

In message
, Arny
Krueger writes
"Don Pearce" wrote in message

On Fri, 20 Oct 2006 19:41:05 +0100, Kevin Seal
wrote:

In message , Don
Pearce writes
On Thu, 19 Oct 2006 23:25:17 +0100, Kevin Seal
wrote:

snip.

http://81.174.169.10/odds/dspkr/v15pink3.gif

Depending on by how much the capacitance has changed,
I would say that the V15-5 was the least sensitive of
the V15's to capacitance loading. The V15-3 being the
most sensitive!

The numbers don't support you here. The V15-3 had an
inductance of 500mH, and the V15-5 was much higher at
720mH. That would make the 5 far more sensitive to
things capacitive than the other.

From the Shure website.....

V15-V
Inductance 330mH
DC resistance 815 Ohms

V15-3
Inductance 500mH
DC resistance 1350 Ohms.

With regards to Arny's post, the V15-3's response would
be affected from about 1kHz upwards if loaded with only
half it's required capacitance. The response would
droop from 1kHz then rise to a peak at around 8 to
10kHz, then drop off again as it approached 20Khz.

I've done the maths for V15-III and V15-V using these
numbers, and the results are here. Note that they are
relative only, and do not reflect the actual flatness of
the cartridge, which will also depend on mechanical
factors.

http://81.174.169.10/odds/v15iii/cartridge.html
http://81.174.169.10/odds/v15v/cartridge.html

The V15-V appears to be more heavily influenced by the
load capacitance.

These curves look a lot like practical reality as I saw
it, back in the days when vinyl was all we had.

The top end is typical shape, but in reality, there
should be a sag in the mid range.

I would suggest that the performance of the mechanical
system was not very much influenced by the cartrdige
loading at that these curves pretty well added to its
response a linear fashion like cascaded amplifier
stages.
I'm sorry Arny, I've read it three times now, but I still
am not sure what you are saying!


OK - a cartridge can be thought of as being two subsytems - the mechanical
subsystem composed of the stylus, moving magnet and suspension, and the
electrical subsystem composed of the pickup coil, and the circuit that loads
it which is composed of a resistor and capacitor in parallel. They are
coupled by a varying magnetic field.

In general, the mechanical and electrical systems interact to some degree.
In this case it seems like the interaction is mostly one-way, from the
stylus assembly and moving magnet, to the pickup coil.

Both the mechanical subsystem and the electrical subsystem have frequency
response characteristics, like equalizers. Because there is very little
reverse coupling, the response of the whole system seems to be a lot like
two equalizers that are cascaded the usual way.

In message , Don Pearce
writes
On Fri, 20 Oct 2006 19:41:05 +0100, Kevin Seal wrote:

In message , Don Pearce
writes
On Thu, 19 Oct 2006 23:25:17 +0100, Kevin Seal wrote:

snip.

http://81.174.169.10/odds/dspkr/v15pink3.gif

Depending on by how much the capacitance has changed, I would say that
the V15-5 was the least sensitive of the V15's to capacitance loading.
The V15-3 being the most sensitive!

The numbers don't support you here. The V15-3 had an inductance of
500mH, and the V15-5 was much higher at 720mH. That would make the 5
far more sensitive to things capacitive than the other.

From the Shure website.....

V15-V
Inductance 330mH
DC resistance 815 Ohms

V15-3
Inductance 500mH
DC resistance 1350 Ohms.

With regards to Arny's post, the V15-3's response would be affected from
about 1kHz upwards if loaded with only half it's required capacitance.
The response would droop from 1kHz then rise to a peak at around 8 to
10kHz, then drop off again as it approached 20Khz.

I've done the maths for V15-III and V15-V using these numbers, and the
results are here. Note that they are relative only, and do not reflect
the actual flatness of the cartridge, which will also depend on
mechanical factors.

http://81.174.169.10/odds/v15iii/cartridge.html
http://81.174.169.10/odds/v15v/cartridge.html

The V15-V appears to be more heavily influenced by the load
capacitance.

I can only go by practical experience. Ten years testing cartridges
using an SME 3009S2 Improved tone arm, Thorens TD125 deck in SME plinth,
B & K test equipment and records.
The results were that the V15V was much less susceptible to capacitive
loading than the V15III.
And as I said above, the effects of too lower a capacitance was that the
response sagged from 1kHz by a good half to one dB before peaking as per
your plots.
I'm no good at maths on this scale, but all plots I ran all Shure
cartridges (and other brand MM cartridges) always showed a dip before
the peak.
--
Kevin Seal
F800ST
{kevin at the hyphen seal hyphen house dot freeserve dot co dot uk}

On Sun, 22 Oct 2006 16:29:12 +0100, Kevin Seal wrote:

In message , Don Pearce
writes
On Fri, 20 Oct 2006 19:41:05 +0100, Kevin Seal wrote:

In message , Don Pearce
writes
On Thu, 19 Oct 2006 23:25:17 +0100, Kevin Seal wrote:

snip.

http://81.174.169.10/odds/dspkr/v15pink3.gif

Depending on by how much the capacitance has changed, I would say that
the V15-5 was the least sensitive of the V15's to capacitance loading.
The V15-3 being the most sensitive!

The numbers don't support you here. The V15-3 had an inductance of
500mH, and the V15-5 was much higher at 720mH. That would make the 5
far more sensitive to things capacitive than the other.

From the Shure website.....

V15-V
Inductance 330mH
DC resistance 815 Ohms

V15-3
Inductance 500mH
DC resistance 1350 Ohms.

With regards to Arny's post, the V15-3's response would be affected from
about 1kHz upwards if loaded with only half it's required capacitance.
The response would droop from 1kHz then rise to a peak at around 8 to
10kHz, then drop off again as it approached 20Khz.

I've done the maths for V15-III and V15-V using these numbers, and the
results are here. Note that they are relative only, and do not reflect
the actual flatness of the cartridge, which will also depend on
mechanical factors.

http://81.174.169.10/odds/v15iii/cartridge.html
http://81.174.169.10/odds/v15v/cartridge.html

The V15-V appears to be more heavily influenced by the load
capacitance.

I can only go by practical experience. Ten years testing cartridges
using an SME 3009S2 Improved tone arm, Thorens TD125 deck in SME plinth,
B & K test equipment and records.
The results were that the V15V was much less susceptible to capacitive
loading than the V15III.
And as I said above, the effects of too lower a capacitance was that the
response sagged from 1kHz by a good half to one dB before peaking as per
your plots.
I'm no good at maths on this scale, but all plots I ran all Shure
cartridges (and other brand MM cartridges) always showed a dip before
the peak.

As I said, I am not saying these show the response of the cartridge,
which has many mechanical factors affecting it. What my posts show is
the way the response *changes* with capacitive loading. There could be
all sorts of lumps, bumps and sags in the actual response, but that is
not what I'm dealing with.

d

--
Pearce Consulting
http://www.pearce.uk.com

--
Posted via a free Usenet account from http://www.teranews.com

In message , Don Pearce
writes
On Sun, 22 Oct 2006 16:29:12 +0100, Kevin Seal wrote:

In message , Don Pearce
writes
On Fri, 20 Oct 2006 19:41:05 +0100, Kevin Seal wrote:

In message , Don Pearce
writes
On Thu, 19 Oct 2006 23:25:17 +0100, Kevin Seal wrote:

snip.

http://81.174.169.10/odds/dspkr/v15pink3.gif

Depending on by how much the capacitance has changed, I would say that
the V15-5 was the least sensitive of the V15's to capacitance loading.
The V15-3 being the most sensitive!

The numbers don't support you here. The V15-3 had an inductance of
500mH, and the V15-5 was much higher at 720mH. That would make the 5
far more sensitive to things capacitive than the other.

From the Shure website.....

V15-V
Inductance 330mH
DC resistance 815 Ohms

V15-3
Inductance 500mH
DC resistance 1350 Ohms.

With regards to Arny's post, the V15-3's response would be affected from
about 1kHz upwards if loaded with only half it's required capacitance.
The response would droop from 1kHz then rise to a peak at around 8 to
10kHz, then drop off again as it approached 20Khz.

I've done the maths for V15-III and V15-V using these numbers, and the
results are here. Note that they are relative only, and do not reflect
the actual flatness of the cartridge, which will also depend on
mechanical factors.

http://81.174.169.10/odds/v15iii/cartridge.html
http://81.174.169.10/odds/v15v/cartridge.html

The V15-V appears to be more heavily influenced by the load
capacitance.

I can only go by practical experience. Ten years testing cartridges
using an SME 3009S2 Improved tone arm, Thorens TD125 deck in SME plinth,
B & K test equipment and records.
The results were that the V15V was much less susceptible to capacitive
loading than the V15III.
And as I said above, the effects of too lower a capacitance was that the
response sagged from 1kHz by a good half to one dB before peaking as per
your plots.
I'm no good at maths on this scale, but all plots I ran all Shure
cartridges (and other brand MM cartridges) always showed a dip before
the peak.

As I said, I am not saying these show the response of the cartridge,
which has many mechanical factors affecting it. What my posts show is
the way the response *changes* with capacitive loading. There could be
all sorts of lumps, bumps and sags in the actual response, but that is
not what I'm dealing with.

But if your maths do not show what real world tests produce, surely
something is missing from the equation?
--
Kevin Seal
F800ST
{kevin at the hyphen seal hyphen house dot freeserve dot co dot uk}