Cartridge loading - does it matter?

I recently acquired a low output (0.2mV) moving coil cartridge
(Sumiko Talisman B), for which the manufacturers' recommend a load of
40-100 ohms. I am currently running it into a load of 47k as my standard
RIAA preamp has sufficient gain, albeit with a bit more noise than for
the earlier MM cartridge, but nevertheless, perfectly acceptable. My
question is:- as MC cartridges are voltage sources (and Sumiko's manual
also says) then why should the load matter once it is, say, 10x greater
than the source impedance of the generator, which in my case is 5.8
ohms. The sound I'm getting seems fine, so I would like to know what
change/improvement I should expect from a lower impedance load.

Thanks

S.

Serge Auckland wrote:

I recently acquired a low output (0.2mV) moving coil cartridge
(Sumiko Talisman B), for which the manufacturers' recommend a load of
40-100 ohms. I am currently running it into a load of 47k as my standard
RIAA preamp has sufficient gain, albeit with a bit more noise than for
the earlier MM cartridge, but nevertheless, perfectly acceptable. My
question is:- as MC cartridges are voltage sources (and Sumiko's manual
also says) then why should the load matter once it is, say, 10x greater
than the source impedance of the generator, which in my case is 5.8
ohms. The sound I'm getting seems fine, so I would like to know what
change/improvement I should expect from a lower impedance load.

Damping possibly. As in avoiding resonances.

Graham

"Serge Auckland" wrote in message
...


albeit with a bit more noise than for
the earlier MM cartridge,
Sumiko is a perfectionist and that is why.
--
John the West Ham fan

In article , Serge Auckland
wrote:

I recently acquired a low output (0.2mV) moving coil cartridge (Sumiko
Talisman B), for which the manufacturers' recommend a load of 40-100
ohms. I am currently running it into a load of 47k as my standard RIAA
preamp has sufficient gain, albeit with a bit more noise than for the
earlier MM cartridge, but nevertheless, perfectly acceptable. My
question is:- as MC cartridges are voltage sources (and Sumiko's manual
also says) then why should the load matter once it is, say, 10x greater
than the source impedance of the generator, which in my case is 5.8
ohms. The sound I'm getting seems fine, so I would like to know what
change/improvement I should expect from a lower impedance load.

Any changes would depend on details you have not given (and presumably are
unknown to you).

A lower amplifier input impedance might also provide lower noise.

Since no source will be an ideal 'voltage source' a lower load may also
change the frequency response, or distortion, or some other parameter.
Perhaps even alter the compliance to a small extent.

At some point the coil inductance, etc, may cause a resonance. Probably
well above audio, but might make something like RF pickup more possible in
some circumstances.

But none of the above may apply in your specific case.

Given the high output you could check by simply putting 100 Ohm shunts
across the amp inputs and see if this has any noticable effect.

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

Does it matter? Probably not.

I use a Denon 103s MC cartridge (0.385mV) and after several months of
testing/listening recently I finally settled on 47K ohms as its best
termination resistance.

I tried several values, 40, 100, 200, 1000, 2000 ohms and 47K ohms. The
lower values displayed a slight resonance in the upper bass, about 1 dB or
so somewhere around the 80-100 Hz I would estimate, just enough to skew the
frequency balance for the male voice. The 1000 and 2000 ohm values smoothes
this low freq rise but then produced a peak in the 6 KHz to 8 KHz region.
The 47K resistance offers the smoothest and most extended frequency response
with neither of these two peaks being audible.

I only tried the 47K loading out of frustration with the lower settings.
All seemed to introduce something not quite right. I must admit that I was
surprised that 47K loading sounded as good as it did -- and better than all
lower impedances as well. As an added bonus (I guess) the S/N ratio is
higher with the higher loading.




"Serge Auckland" wrote in message
...

I recently acquired a low output (0.2mV) moving coil cartridge
(Sumiko Talisman B), for which the manufacturers' recommend a load of
40-100 ohms. I am currently running it into a load of 47k as my standard
RIAA preamp has sufficient gain, albeit with a bit more noise than for the
earlier MM cartridge, but nevertheless, perfectly acceptable. My question
is:- as MC cartridges are voltage sources (and Sumiko's manual also says)
then why should the load matter once it is, say, 10x greater than the
source impedance of the generator, which in my case is 5.8 ohms. The
sound I'm getting seems fine, so I would like to know what
change/improvement I should expect from a lower impedance load.

Thanks

S.

In article , Dish Guy
wrote:
Does it matter? Probably not.

I use a Denon 103s MC cartridge (0.385mV) and after several months of
testing/listening recently I finally settled on 47K ohms as its best
termination resistance.

I tried several values, 40, 100, 200, 1000, 2000 ohms and 47K ohms. The
lower values displayed a slight resonance in the upper bass, about 1 dB
or so somewhere around the 80-100 Hz I would estimate, just enough to
skew the frequency balance for the male voice. The 1000 and 2000 ohm
values smoothes this low freq rise but then produced a peak in the 6
KHz to 8 KHz region. The 47K resistance offers the smoothest and most
extended frequency response with neither of these two peaks being
audible.

Is the above based on measurements? If so, I'd be interested to see the
details. Can you also say what level of cable/amp capacitance was used?

I only tried the 47K loading out of frustration with the lower settings.
All seemed to introduce something not quite right. I must admit that I
was surprised that 47K loading sounded as good as it did -- and better
than all lower impedances as well. As an added bonus (I guess) the S/N
ratio is higher with the higher loading.

I am not sure that a higher load impedance will mean a better SNR. This
will depend on the details of the noise generation mechanisms involved as
well as the source 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

Dish Guy wrote:
Does it matter? Probably not.

I use a Denon 103s MC cartridge (0.385mV) and after several months of
testing/listening recently I finally settled on 47K ohms as its best
termination resistance.

I tried several values, 40, 100, 200, 1000, 2000 ohms and 47K ohms. The
lower values displayed a slight resonance in the upper bass, about 1 dB or
so somewhere around the 80-100 Hz I would estimate, just enough to skew the
frequency balance for the male voice. The 1000 and 2000 ohm values smoothes
this low freq rise but then produced a peak in the 6 KHz to 8 KHz region.
The 47K resistance offers the smoothest and most extended frequency response
with neither of these two peaks being audible.

I only tried the 47K loading out of frustration with the lower settings.
All seemed to introduce something not quite right. I must admit that I was
surprised that 47K loading sounded as good as it did -- and better than all
lower impedances as well. As an added bonus (I guess) the S/N ratio is
higher with the higher loading.



Out of interest, what arm are you using? The 103 is better matched to
higher mass arms, being a lot lower compliance than most of todays
cartridges. It often gives better results with extra mass being added at
the headshell (6gm or so).

This may have contributed more the the bass problem than the loading.

--
Nick

Serge Auckland wrote:
I recently acquired a low output (0.2mV) moving coil cartridge
(Sumiko Talisman B), for which the manufacturers' recommend a load of
40-100 ohms. I am currently running it into a load of 47k as my standard
RIAA preamp has sufficient gain, albeit with a bit more noise than for
the earlier MM cartridge, but nevertheless, perfectly acceptable. My
question is:- as MC cartridges are voltage sources (and Sumiko's manual
also says) then why should the load matter once it is, say, 10x greater
than the source impedance of the generator, which in my case is 5.8
ohms. The sound I'm getting seems fine, so I would like to know what
change/improvement I should expect from a lower impedance load.

Thanks


I have a cartridge that is also recomended to be loaded at 100 ohms. My
preamp allows for variable loading. At 47k it sounds more lively but
that livelyness seems to be a form of glare. Some people like this. I
don't.


Scott

In article ,
Dish Guy wrote:
I only tried the 47K loading out of frustration with the lower settings.
All seemed to introduce something not quite right. I must admit that I
was surprised that 47K loading sounded as good as it did -- and better
than all lower impedances as well. As an added bonus (I guess) the S/N
ratio is higher with the higher loading.

What's the recommended load for the cart?

--
*When the going gets tough, the tough take a coffee break *

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

Rega Planar 3 turntable, (new) RB-300 arm and Denon 103s cartridge.


"Nick Gorham" wrote in message
...
Dish Guy wrote:
Does it matter? Probably not.

I use a Denon 103s MC cartridge (0.385mV) and after several months of
testing/listening recently I finally settled on 47K ohms as its best
termination resistance.

I tried several values, 40, 100, 200, 1000, 2000 ohms and 47K ohms. The
lower values displayed a slight resonance in the upper bass, about 1 dB
or so somewhere around the 80-100 Hz I would estimate, just enough to
skew the frequency balance for the male voice. The 1000 and 2000 ohm
values smoothes this low freq rise but then produced a peak in the 6 KHz
to 8 KHz region. The 47K resistance offers the smoothest and most
extended frequency response with neither of these two peaks being
audible.

I only tried the 47K loading out of frustration with the lower settings.
All seemed to introduce something not quite right. I must admit that I
was surprised that 47K loading sounded as good as it did -- and better
than all lower impedances as well. As an added bonus (I guess) the S/N
ratio is higher with the higher loading.



Out of interest, what arm are you using? The 103 is better matched to
higher mass arms, being a lot lower compliance than most of todays
cartridges. It often gives better results with extra mass being added at
the headshell (6gm or so).

This may have contributed more the the bass problem than the loading.

--
Nick