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View Full Version : Resonance of the Jelco SA-750L(B) / Denon 103R combination



kor952
01-05-2012, 16:32
Today I have meassured the resonance of the above combination with a (analog) amplified Voltmeter and a test record. The result was 8 Hz.
The mass of the Denon 103R is 8.5 g, the mass of the Jelco HS-25 headshell is 12 g, totals 20.5g. This results, due to several diagrams, in a eff. mass of the arm between 20 and 27 g (w/o headshell), presumed the compliance of the 103R is between 8.5 and 10 um/mN at 10 Hz.
I think the eff. mass of the 750L is rather high and it will be difficult to find other suitable cartridges for this arm, I think only the Denon 103/103R and Ortofon SPUs will suit. My Benz Micro Glider with a compliance of 14 um/mN already has a too high compliance for this arm.
Anyone any idea wich other carts would suit this arm?

Ronald.

gx502
02-05-2012, 03:14
I am using an Ortofon Kontrapunkt-B in combination with an Ortofon LH-6000 headshell with my Jelco SA-750D.

It seems to work fine, but I have no idea on the total effective mass, or what the arm/cart resonance value should be.

It works very well.

kor952
02-05-2012, 10:04
The eff. mass of the SA-750D will be (much?) lower as the 12" SA-750L. So you will be able to use a bigger variaty of cartridge/headshell combinations on the 750D.

Ronald

gx502
02-05-2012, 10:26
The eff. mass of the SA-750D will be (much?) lower as the 12" SA-750L. So you will be able to use a bigger variaty of cartridge/headshell combinations on the 750D.

Ronald

Apologies, I only realised later that you have the 750L -my bad oops!!!

Ivano
12-12-2012, 13:31
Interesting, that my combo Denon 103D (compliance 12 at 100Hz) and Jelco SA-750L (no damping fluid) has resonance at around 8 Hz as well according to test LP.

kor952
12-12-2012, 14:14
Later I did some static measurements trying to find the Jelco SA-750Ls effective mass w/o headshell.
With heavy counterweight it is 12.8 g and with default counterweight it is 10.24 g.
I did find a thread on Vinyl-Engine wich describes how to do it.

http://www.vinylengine.com/turntable_forum/viewtopic.php?t=24136

Due to these results I think the dynamic compliance of the Denon 103R at 10 Hz will be about 10-11 um/mN.

Ronald.