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Medium Mass or Low Mass Tonearms?

Many manufacturers of the tonearms used in audio today do not disclose effective mass of the arm.  How can you determine what cartridge will work with the arm if you do not know the effective mass of the arm?  Most VPI arms are low mass arms but many people still use medium to lower compliance moving coil cartridges on their arms.  Even the 3d arm on the Prime is a low effective mass arm, lower in mass than the JMW 9.  Wouldn't that increase the likelihood of excessive record wear?  I would imagine you would want to use high compliance moving magnet cartridges on most if not all of their arms.  What is the effective mass of Rega arms, Graham arms, SME arms?  Also on my VPI table for example a benz glider falls into the good resonance area on the resonance calculator but it is a medium compliance cartridge better suited on medium mass arm  Am I ruining my vinyl and not realizing it?
tzh21y
7 responses Add your response
harold-not-the-barrel
895 posts
 
SME III w/ its very light 5.0 g internally teak damp titanium nitride slightly S-shaped arm is the finest ever produced for high compliance MM (IM, MI) carts. Additionally you can use headshell weights 2.2 g or/and 4.4 g to fit lower compliance MC carts. The sound quality using SHURE´s top models and many other top MM carts is just superb. And it´s cheap, you can get one under $500. There´s one very special w/ Van den Hul MCS-300 silver wired direct-to-phono on eBay at the moment. Classics never die :)

https://www.ebay.de/itm/SME-III-Van-den-Hul-MCS-300-silver-wiring-direct-to-phono-EXCELLENT-orig-par...
yogiboy's avatar
yogiboy
5,661 posts
 
Here ya go! This will give you the information you are looking for!
https://www.vinylengine.com/tonearm_database.php
https://www.vinylengine.com/cartridge_resonance_evaluator.php
brf
1,715 posts
 
By some manufactures and other industry professionals, medium mass tonearms are defined as having an effective mass between 9-25 grams.  That would put VPI tonearms at the very low end of medium mass and that would account for their wide compatiblity with most modern MC cartridges.
tzh21y OP
1,654 posts
 
I have read that anything with an effective mass of 10 grams and lower is low mass.  Did somebody change these parameters
chakster's avatar
chakster
6,144 posts
 
@tzh21y all you need is a Test Record to physically measure the resonance frequency of your tonearm/cartridge combo, you will see when your cartridge/tonearm resonance, you can use this one https://www.needledoctor.com/Hi-Fi-News-Test-Record 

Make sure to find out the compliance of your cartridge @ 10Hz, not at 100Hz like with all Japanese cartridges. If you know the exact compliance of the cartridge @10Hz in CU then you can use this diagram: https://www.ortofon.com/support/support-hifi/resonance-frequency 


bdp24's avatar
bdp24
9,788 posts
 
tzh21y---Don't worry about your LP's; a mismatch between an arm's moving mass and a cartridge's compliance results in, not groove damage, but, as others are pointing to here, a too-high or too-low resonant frequency. What WILL cause groove damage is dirty records (you MUST have a good record cleaner, at least a VPI HW-16.5), stylus wear, and arm bearing friction.
tzh21y OP
1,654 posts
 
I have read that it is the way the cartridge resonates in the groove that causes the damage to the record.
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