Tonearm mass, cartridge compliance, and similarly confusing things!

[jls001]

I'd been reading up on what is the meaning and significance of tonearm mass and cartridge compliance. To summarise what I understood:

Tonearm Mass:
Low: less than or equal to 10 gms
Moderate: 11 to 25 gms
High: >25 gms

Cartridge Compliance seems to be measured in two units:
First
Low: 12x10^-6 cm/dyne
High: 13x10^-6 to 25x10^-6 cm/dyne

OR
Low: 5 to 10 um/mN
Moderate: 10 to 20
High: >35

I currently have only Shure cartridges (M44-7, M55E, M97xE) for which I could find effective cartridge masses and recommended tracking forces. But compliance ratings seems quite elusive. Any pointers where Shure cart compliances are published?

Further, my Pioneer PL 200 TT's spec says recommended cartridge weight is 4 to 9 gms so all the cartridges qualify on that count alone, but is silent on tonearm mass (not that I can change it). Any pointers on where I can find this info? Even the manual mentions only recommended cartridge weight.

Also, I have been trying to get my Thorens TD 160 B Mk II with an ADC carbon fiber LMF-2 tonearm (mass 6 gms), to sing. I have tried Shure M44-7 as well as M55E. I have tried my level best to balance the tonearm, set proper counterweight, set tracking force, etc, but I find that it tends to get stuck in the groove, irrespective of cartridge used or records played. But when it does sing ocassionally, it does sing a better tune than my PL200. A much better dynamics is quite apparent and music seems more immediate. I have tried quite a large number of records, including known good ones, just to rule out record problems.

On the Thorens, am I having a bad tonearm mass/cartridge compliance match? All pointers highly welcome.

Joshua

 

[murali_n]

Hi jlsoo1,

Here is the link for Shure M97xE Cartridge specs and user guide. I hope you have installed the cartridge properly and balanced the tonearm before adjusting the weight on the cartridge :

http://www.shure.com/idc/groups/tech_pubs/@global_managed/documents/webcontent/us_pro_m97xe_ug.pdf

N.Murali

 

[Rajiv]

Also, I have been trying to get my Thorens TD 160 B Mk II with an ADC carbon fiber LMF-2 tonearm (mass 6 gms), to sing. I have tried Shure M44-7 as well as M55E. I have tried my level best to balance the tonearm, set proper counterweight, set tracking force, etc, but I find that it tends to get stuck in the groove, irrespective of cartridge used or records played. But when it does sing ocassionally, it does sing a better tune than my PL200. A much better dynamics is quite apparent and music seems more immediate. I have tried quite a large number of records, including known good ones, just to rule out record problems.

Hi,

Check if the bearings in the arm are OK.

This can be detected by free-floating the arm and allowing it to swing over the playing area, damaged bearings tend to move in a 'notchy' way, e.g. tend to want to stick at several specific points in their travel.

You could try this test that was mentioned on another forum.

This is not very scientific, but it will give you an idea as to your tonearm's condition.

Cut a piece of paper about the size of a postage stamp. Next, adjust your tonearm, so that it free floats. Put the paper on top of the headshell, and gently blow on the paper from the side. If the tonearm travels without the paper blowing off, it is most likely in excellent condition. Obviously, a slight puff is all it takes, so don't be surprised if it requires several tries.

One more test.

Cut a 5cm wide strip from the long side of the paper. Cut this into 0.5x5cm, 1x5cm, 2x 5cm, 3x5cm etc sections.

Then balance the arm so it is free floating vertically with anti skate turned off.

Then you hold a strip of paper between thumb and first finger, pinch no more than 1cm down the paper, and then use the bottom of the paper to try and push the headshell across the deck without bending the paper more than few degrees.

A good gimball arm will go with the 1cm sheet, and a good uni will comfortably go with the .5cm. If it doesn't move with the 2cm then it's poor and if the 3cm can't move it then its knackered.

it's a little easier than dismantling it for the swing test, which tells you little other than you have a heavy headshell.

Try the following calculator to find the cartridges suitable for your tonearm.

Cartridge Resonance Evaluator


Regards
Rajiv

 

[Hiten]

Cut a piece of paper about the size of a postage stamp. Next, adjust your tonearm, so that it free floats. Put the paper on top of the headshell, and gently blow on the paper from the side. If the tonearm travels without the paper blowing off, it is most likely in excellent condition. Obviously, a slight puff is all it takes, so don't be surprised if it requires several tries.

This is interesting and helpful thanks.

 

[jls001]

Check if the bearings in the arm are OK.

Thanks, Rajiv.
Will try both the blow test and the 5cm strip test.

Thanks for the pointer to the resonance evaluator.

I browsed a bit and found on Vinyl Engine itself Cartridge Database Cartridge Database | Vinyl Engine. There is a mention of the compliance ratings if one enters the cart make and model. Thanks again.

Joshua

Problem resolved. Partially. For now. I'd totally forgotten I'd downloaded the manual for my Pioneer PL200. Read through all (13 pages) of it, learned the idea of how to balance the tonearm, and balanced the Pioneer. Applied the same process to ADC LMF-2 on the Thorens TD160 B Mark II. No more getting stuck in the groove, except once or twice.

A reading of the LMF-2 manual suggested a slight variation on balancing so did that too (afresh).

Also adjusted distance of stylus (using Shure M44-7) tip distance as suggested in ADC manual.

End result..
TD 160 seems better now in terms of ability to play on without getting stuck. Have observed it getting stuck only once post the balancing but I think it was due to the record itself and no longer because of the player. I played a couple of my reference records and they played without getting stuck. Longer term observation is required to know for sure.

..and side effects
the highs seem now rolled off compared to earlier. Also, there seems to be a new-found bloat in the mid bass.

Additional tweaks done - adjusted the azimuth of the headshell slightly as left channel sounds lower. But this does not improve the abovementioned highs and mid bass.

Any pointers?
Joshua

Tried changing cartridge to Shure M55E, but the muddy mids and rolled-off high still persists, and the bass definition is still less than sterling. So it's back to the good old Pioneer PL200 using the Shure M44-7. Need to try the new Shure M97xE, too.

PS: anyone's bought an Ortofon cart from Sound Of Music, Delhi? They are quite unresponsive.
Joshua