Matching cartridge for Grace 747 tonearm

[MDS]

Hello, looking to get into vinyl again
It has been ages

I have a Grace 747 tonearm which will be mounted on a friends Thorens 125 deck

I have a couple of cartridges available:
Goldring 2200 (new)
Hana EH
Rega Carbon

Would any of these fit ?

I recall the 747 as the older 707 arm, were not really happy with a number of low compliant cartridges, not that I have any proper tech knowledge in that direction but remember not everything was recommended

Any help appreciated

[Barry]

The Denon DL103 is a good match with the Grace 747 arm. It is a low compliance cartridge (~ 10cu), so I would imagine other cartridges having a similar compliance would suit.

I've always regarded the Grace 747 as being superior to the 707.


Leave it with me - I'll look up the relevant arm and cartridge data, do the sums and get back to you.

[Barry]

The relevant data for the Grace 747 remains elusive. At the moment, all I can ascertain is it is a low mass arm; usually classed as an arm with an effective mass of 10g or less. In the absence of a more accurate figure, I'll take a figure of 10g. I'll also assume a figure of 0.5g for the weight of the cartridge fixings.

Goldring 2200

This has a mass of 7.4g and a dynamic compliance (at 10Hz) of 16cu, so the calculated low frequency resonance is 9.4 Hz.


Hana EH

This has a mass of 5.0g and a dynamic compliance of 20cu, giving a calculated low frequency resonance of 9.0 Hz.


Rega 'Carbon'

Rega are exasperatingly laconic with the specification of this cartridge. However since it is strongly based on the Audio Technica AT91, I'll assume the Carbon has the same mass (5.7g) and dynamic compliance (at 100Hz) of 6.5cu. The dynamic compliance at 10Hz is ~ 1.5 - 1.75 x the compliance at 100Hz; so I'll take a figure of between 9.8 and 11.4cu. The calculated low frequency resonance is 11.7 - 12.7Hz.

All of these results lay within the 'safe zone' of 8 - 12Hz, so all three cartridges ought to be mechanically compatible with the 747 arm.

These are calculated results however, and I have made a fairly large assumption of the effective mass of the Grace 747 arm.

[MDS]

Thanks Barry

Unfortunately those figures are kryptic for me, guess I will just fit the Hana first off seeing how this goes

Thanks anyway

[Barry]

Hello Per,

Sorry if the calculated figures appear 'cryptic' to you. All they show is that all three cartridges ought to work satisfactorily in your Grace 747 arm.

This might help you understand the calculations: https://theartofsound.net/forum/showthread.php?22373-Arm-cartridge-resonance

Barry