[Guy 13]

Hi all Audio Circle members.
I've seen it several times on different makes of turntables
but don't know why they do it that way.
There must be a reason and/or and advantage.
The counter weight is not monted directly on the arm's tube,
but via a decoupling.
What's the reason/advantage.



Waiting for a logical reason.

Guy 13

[apollophono]

I've seen it too on other turntables and I'm not sure it makes any difference
SQ-wise.  Also it makes more of a chance on screwing up the chance that the
weight is not centered on the tonearm correctly.  That wouldn't matter much
either as most tonearms have a finger pick-up on the end also.  Another
gimmick to justify a higher price?

[MaxCast]

My guess it is a cost saving measure.  It is cheaper to mount the weight and slide the tone arm back and forth for balance and VTF vs. machining/threading a counterweight on the arm itself.  At least that is what I gather from the pic.

[Funnehaha]

Did anyone think about the physics involved here?

Lowering the center of gravity for the tonearm system probably increases its stability. The stylus and cartidge are actually underneath the main shaft of the tonearm, so if you didn't put the counterweight at the same level or about the same level, the slanted axis of balance would make the arm more unstable. Someone, balance your tonearm and see if the line between the tip of the stylus and the center of the counterweight shaft is level.

[jtwrace]

Did anyone think about the physics involved here?

Lowering the center of gravity for the tonearm system probably increases its stability. The stylus and cartidge are actually underneath the main shaft of the tonearm, so if you didn't put the counterweight at the same level or about the same level, the slanted axis of balance would make the arm more unstable. Someone, balance your tonearm and see if the line between the tip of the stylus and the center of the counterweight shaft is level.

Science in audio?   

Yes, that is the correct reason!

[Wayner]

Did anyone think about the physics involved here?

Lowering the center of gravity for the tonearm system probably increases its stability. The stylus and cartidge are actually underneath the main shaft of the tonearm, so if you didn't put the counterweight at the same level or about the same level, the slanted axis of balance would make the arm more unstable. Someone, balance your tonearm and see if the line between the tip of the stylus and the center of the counterweight shaft is level.

Bingo! Actually the arm is a uni-pivot, so it needs all the help it can get. AR-XA(XB) tonearms had a dropped counterweight as well, and as others have said, lowers the center of gravity of the arm and aligns the cartridge mass with the tonearm mass.

Wayner

[Funnehaha]

Yep, it's scientific....I may be a "junior member" [that seems somewhat arbitrary...], but I'm cute and a good dancer.   

By the way, I'm in the middle of modifying my second AR XA too.

[Guy 13]

Hi all Audio Circle members.
Are you tired of my boring and beaten up
and always the same introduction ?
Yes, well, I am not.
As a matter of fact I like it very much,
because I am sure it annoy some Audio Circle members.
I want to thank everyone that came up with explanation
about the tone arm of the Orbit.
If I can't convert my Rega P3 from 220V to 120V.
because I can't get the parts or because it's too expensive
and complicated, I might buy the Orbit.
At 65 years old, I am not as demanding as I was at 30 years old.
Therefore, the Orbit will make me happy I am sure.
I don't want to look for a used turntable,
(I prefer new stuff with warranty) however,
I will look anyway, just in case. 
I would like to keep my Rega P3 with it's Exact MM cartridge,
because it's paid for and it's O.K. for me.
However, if I win a few millions at the lottery I will buy a VPI Scout...  
Thanks again and have a nice day.

Guy 13