Doughboy

I've found out that my Gemini PT-2000 has a tonearm mass of 9g, which
is lower than the Technic SL1200's 12g.

Does this qualify it as a high mass tonearm, therefore making carts
such as the Ortofon 510 or 520, with their high dynamic compliance of
25 µm/mN, or the OM 5E (20 µm/mN), unsuitable for use with this
tonearm? (in which case, can I assume I'd be better of with something
like the Ortofon OM DJ E considering it's lower dynamic compliance
9µm/mN, not to mention it's better trackability)


Doughboy

James Boyk

Doughboy wrote:

> I've found out that my Gemini PT-2000 has a tonearm mass of 9g, which
> is lower than the Technic SL1200's 12g.

Is this the "effective" mass (diff. from total mass)? If so, that's fairly low.


> Does this qualify it as a high mass tonearm, therefore making carts
> such as the Ortofon 510 or 520, with their high dynamic compliance of
> 25 µm/mN, or the OM 5E (20 µm/mN), unsuitable for use with this
> tonearm? (in which case, can I assume I'd be better of with something
> like the Ortofon OM DJ E considering it's lower dynamic compliance
> 9µm/mN, not to mention it's better trackability)


Is µm/mN numerically equal to the old compliance unit of 10^(-6) dynes / cm ? (I seem to recall that it is; am too lazy to figure it out for myself now.)


What's the mass of these cartridges?


James Boyk

James Boyk

Doughboy wrote:

> I've found out that my Gemini PT-2000 has a tonearm mass of 9g, which
> is lower than the Technic SL1200's 12g.

Is this the "effective" mass (diff. from total mass)? If so, that's fairly low.


> Does this qualify it as a high mass tonearm, therefore making carts
> such as the Ortofon 510 or 520, with their high dynamic compliance of
> 25 µm/mN, or the OM 5E (20 µm/mN), unsuitable for use with this
> tonearm? (in which case, can I assume I'd be better of with something
> like the Ortofon OM DJ E considering it's lower dynamic compliance
> 9µm/mN, not to mention it's better trackability)


Is µm/mN numerically equal to the old compliance unit of 10^(-6) dynes / cm ? (I seem to recall that it is; am too lazy to figure it out for myself now.)


What's the mass of these cartridges?


James Boyk

Doughboy

On Tue, 02 Sep 2003 10:13:06 -0700, James Boyk <boyk@caltech.edu>
wrote:

>Doughboy wrote:
>
>> I've found out that my Gemini PT-2000 has a tonearm mass of 9g, which
>> is lower than the Technic SL1200's 12g.
>
>Is this the "effective" mass (diff. from total mass)? If so, that's fairly low.

Yes, Effective Mass (without cart) .

>> Does this qualify it as a high mass tonearm, therefore making carts
>> such as the Ortofon 510 or 520, with their high dynamic compliance of
>> 25 µm/mN, or the OM 5E (20 µm/mN), unsuitable for use with this
>> tonearm? (in which case, can I assume I'd be better of with something
>> like the Ortofon OM DJ E considering it's lower dynamic compliance
>> 9µm/mN, not to mention it's better trackability)
>
>
>Is µm/mN numerically equal to the old compliance unit of 10^(-6) dynes / cm ? (I seem to recall that it is; am too lazy to figure it out for myself now.)

I have no idea. I did notice that Grado still quote their carts in
CU's, and quotes figures around 20, so probably.

>What's the mass of these cartridges?

If cartridge weight is the same thing:

OM 5E - 5g
510MK II - 5g
520MK II - 5g
OM DJ E - 5g

Grado DJ100 - 5.5g



Doughboy

Doughboy

On Tue, 02 Sep 2003 10:13:06 -0700, James Boyk <boyk@caltech.edu>
wrote:

>Doughboy wrote:
>
>> I've found out that my Gemini PT-2000 has a tonearm mass of 9g, which
>> is lower than the Technic SL1200's 12g.
>
>Is this the "effective" mass (diff. from total mass)? If so, that's fairly low.

Yes, Effective Mass (without cart) .

>> Does this qualify it as a high mass tonearm, therefore making carts
>> such as the Ortofon 510 or 520, with their high dynamic compliance of
>> 25 µm/mN, or the OM 5E (20 µm/mN), unsuitable for use with this
>> tonearm? (in which case, can I assume I'd be better of with something
>> like the Ortofon OM DJ E considering it's lower dynamic compliance
>> 9µm/mN, not to mention it's better trackability)
>
>
>Is µm/mN numerically equal to the old compliance unit of 10^(-6) dynes / cm ? (I seem to recall that it is; am too lazy to figure it out for myself now.)

I have no idea. I did notice that Grado still quote their carts in
CU's, and quotes figures around 20, so probably.

>What's the mass of these cartridges?

If cartridge weight is the same thing:

OM 5E - 5g
510MK II - 5g
520MK II - 5g
OM DJ E - 5g

Grado DJ100 - 5.5g



Doughboy

James Boyk

Doughboy wrote: ...my Gemini PT-2000 has a tonearm mass of 9g...

[cartridge mass & compliance]
OM 5E: 5g, 20 µm/mN
510MK II: 5g, 25
520MK II: 5g, 25
OM DJ E - 5g, 9
Grado DJ100 - 5.5g, Compliance not given


**
Assuming

(a) the compliance units are the same as the old-fashioned one,

(b) I remember the formula correctly:

Res. Freq. = 1000 / 2* pi * [sqrt [M*C)],

then---



OM 5E: 1000 / [6.28 * sqrt (14*20)] = 9.5 Hz


510, 520: 1000 / [6.28 *sqrt (14*25)] = 8.5 Hz


OM DJ E: 1000 / [6.28 * sqrt (14*9)] = 14.2


Grado DJ100: can't calculate w/out compliance figure.


Comment: The ideal range varies according to commentator, but no one puts it outside the range 10-14 Hertz. My preference is for 12-14. None of these quite fall in that range, but the OM DJ E is probably the most usable as getting the farthest from record warp (ca. 8 Hz) and footfall vibrations. I would not use the 510 or 520.

Much depends on the isolation of your turntable. If it's not isolated from sound fields of the music its playing, then run the monitor level way down or use headphones.

Of course there's more to a cartridge's performance than just this aspect. For instance, you might get a Shure V-15V/MR and use its damping brush. Even though it has high dynamic compliance, you might get better overall results with it than with any of these.


At some point you used the word "transcription." In the old days, this implied super-duper quality. If that's what you want, I doubt that any of this gear will give it.


James Boyk

James Boyk

Doughboy wrote: ...my Gemini PT-2000 has a tonearm mass of 9g...

[cartridge mass & compliance]
OM 5E: 5g, 20 µm/mN
510MK II: 5g, 25
520MK II: 5g, 25
OM DJ E - 5g, 9
Grado DJ100 - 5.5g, Compliance not given


**
Assuming

(a) the compliance units are the same as the old-fashioned one,

(b) I remember the formula correctly:

Res. Freq. = 1000 / 2* pi * [sqrt [M*C)],

then---



OM 5E: 1000 / [6.28 * sqrt (14*20)] = 9.5 Hz


510, 520: 1000 / [6.28 *sqrt (14*25)] = 8.5 Hz


OM DJ E: 1000 / [6.28 * sqrt (14*9)] = 14.2


Grado DJ100: can't calculate w/out compliance figure.


Comment: The ideal range varies according to commentator, but no one puts it outside the range 10-14 Hertz. My preference is for 12-14. None of these quite fall in that range, but the OM DJ E is probably the most usable as getting the farthest from record warp (ca. 8 Hz) and footfall vibrations. I would not use the 510 or 520.

Much depends on the isolation of your turntable. If it's not isolated from sound fields of the music its playing, then run the monitor level way down or use headphones.

Of course there's more to a cartridge's performance than just this aspect. For instance, you might get a Shure V-15V/MR and use its damping brush. Even though it has high dynamic compliance, you might get better overall results with it than with any of these.


At some point you used the word "transcription." In the old days, this implied super-duper quality. If that's what you want, I doubt that any of this gear will give it.


James Boyk

Doughboy

On Tue, 02 Sep 2003 15:20:01 -0700, James Boyk <boyk@caltech.edu>
wrote:

>Doughboy wrote: ...my Gemini PT-2000 has a tonearm mass of 9g...
>
>[cartridge mass & compliance]
>OM 5E: 5g, 20 µm/mN
>510MK II: 5g, 25
>520MK II: 5g, 25
>OM DJ E - 5g, 9
>Grado DJ100 - 5.5g, Compliance not given
>
>
>**
>Assuming
>
>(a) the compliance units are the same as the old-fashioned one,
>
>(b) I remember the formula correctly:
>
> Res. Freq. = 1000 / 2* pi * [sqrt [M*C)],
>
>then---
>
>
>
>OM 5E: 1000 / [6.28 * sqrt (14*20)] = 9.5 Hz
>
>
>510, 520: 1000 / [6.28 *sqrt (14*25)] = 8.5 Hz
>
>
>OM DJ E: 1000 / [6.28 * sqrt (14*9)] = 14.2
>
>
>Grado DJ100: can't calculate w/out compliance figure.
>
>
>Comment: The ideal range varies according to commentator, but no one puts it outside the range 10-14 Hertz. My preference is for 12-14. None of these quite fall in that range, but the OM DJ E is probably the most usable as getting the farthest from record warp (ca. 8 Hz) and footfall vibrations. I would not use the 510 or 520.
>
>Much depends on the isolation of your turntable. If it's not isolated from sound fields of the music its playing, then run the monitor level way down or use headphones.
>
>Of course there's more to a cartridge's performance than just this aspect. For instance, you might get a Shure V-15V/MR and use its damping brush. Even though it has high dynamic compliance, you might get better overall results with it than with any of these.

Thanks for the useful info. It does seem that the OM DJ E is my best
bet. The Shure V-15V/MR (or even the M97xE) is too expensive for me.
As for the isolation issue, I'll just use headphones to monitor when
recording to avoid any complications, although I think the turntable's
feet offer quite good isolation.

>At some point you used the word "transcription." In the old days, this implied super-duper quality. If that's what you want, I doubt that any of this gear will give it.

I probably shouldn't have used that word. I was just trying to convey
that I want to purchase a cartridge suitable for making reasonably
high quality recordings.



Doughboy

Doughboy

On Tue, 02 Sep 2003 15:20:01 -0700, James Boyk <boyk@caltech.edu>
wrote:

>Doughboy wrote: ...my Gemini PT-2000 has a tonearm mass of 9g...
>
>[cartridge mass & compliance]
>OM 5E: 5g, 20 µm/mN
>510MK II: 5g, 25
>520MK II: 5g, 25
>OM DJ E - 5g, 9
>Grado DJ100 - 5.5g, Compliance not given
>
>
>**
>Assuming
>
>(a) the compliance units are the same as the old-fashioned one,
>
>(b) I remember the formula correctly:
>
> Res. Freq. = 1000 / 2* pi * [sqrt [M*C)],
>
>then---
>
>
>
>OM 5E: 1000 / [6.28 * sqrt (14*20)] = 9.5 Hz
>
>
>510, 520: 1000 / [6.28 *sqrt (14*25)] = 8.5 Hz
>
>
>OM DJ E: 1000 / [6.28 * sqrt (14*9)] = 14.2
>
>
>Grado DJ100: can't calculate w/out compliance figure.
>
>
>Comment: The ideal range varies according to commentator, but no one puts it outside the range 10-14 Hertz. My preference is for 12-14. None of these quite fall in that range, but the OM DJ E is probably the most usable as getting the farthest from record warp (ca. 8 Hz) and footfall vibrations. I would not use the 510 or 520.
>
>Much depends on the isolation of your turntable. If it's not isolated from sound fields of the music its playing, then run the monitor level way down or use headphones.
>
>Of course there's more to a cartridge's performance than just this aspect. For instance, you might get a Shure V-15V/MR and use its damping brush. Even though it has high dynamic compliance, you might get better overall results with it than with any of these.

Thanks for the useful info. It does seem that the OM DJ E is my best
bet. The Shure V-15V/MR (or even the M97xE) is too expensive for me.
As for the isolation issue, I'll just use headphones to monitor when
recording to avoid any complications, although I think the turntable's
feet offer quite good isolation.

>At some point you used the word "transcription." In the old days, this implied super-duper quality. If that's what you want, I doubt that any of this gear will give it.

I probably shouldn't have used that word. I was just trying to convey
that I want to purchase a cartridge suitable for making reasonably
high quality recordings.



Doughboy

James Boyk

Doughboy wrote: > Thanks for the useful info.


You're very welcome.



> ...It does seem that the OM DJ E is my best
> bet. The Shure V-15V/MR (or even the M97xE) is too expensive for me.
> As for the isolation issue, I'll just use headphones to monitor when
> recording to avoid any complications, although I think the turntable's
> feet offer quite good isolation.


This is *extremely* unlikely. I've never seen feet that did. The only good isolation I've ever seen has come from a subchassis suspension a la Linn Sondek, AR or other similar turntables. But if the support is solid and there's no sound field for the turntable to need isolation from, things should be copacetic, as we used to say here in the '70's.



> I probably shouldn't have used that word. I was just trying to convey
> that I want to purchase a cartridge suitable for making reasonably
> high quality recordings.


Of course I know nothing about these cartridges' sound quality, so you're on your own.


Good luck.


jb

James Boyk

Doughboy wrote: > Thanks for the useful info.


You're very welcome.



> ...It does seem that the OM DJ E is my best
> bet. The Shure V-15V/MR (or even the M97xE) is too expensive for me.
> As for the isolation issue, I'll just use headphones to monitor when
> recording to avoid any complications, although I think the turntable's
> feet offer quite good isolation.


This is *extremely* unlikely. I've never seen feet that did. The only good isolation I've ever seen has come from a subchassis suspension a la Linn Sondek, AR or other similar turntables. But if the support is solid and there's no sound field for the turntable to need isolation from, things should be copacetic, as we used to say here in the '70's.



> I probably shouldn't have used that word. I was just trying to convey
> that I want to purchase a cartridge suitable for making reasonably
> high quality recordings.


Of course I know nothing about these cartridges' sound quality, so you're on your own.


Good luck.


jb