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Tonearm mount on the plinth or on Pillar ?

Folks,
I am looking to buy a custom built turntable from Torqueo Audio (http://www.torqueo-audio.it/). They have two models, one with a wide base plinth where the tonearm would be mounted on the plinth (as usual) and the second is a compact plinth where they provide a seperate tonearm pillar to mount the tonearm. According to them the separate tonearm pillar version sounds more transparent and quieter because of the isolation of the tonearm from the TT. My concern is whether seperating the tonearm from the plinth would result in a lesser coherence in sound ? Isnt sharing the same platform results in a more well-timed, coherent presentation ? Any opinions ?
pani
chakster's avatar
chakster
6,144 posts
 
Lewn, it looks very attractive, i’m afraid this is vintage advertising.

There is only phone number on the poster!
Someone should call TEL/ (03) 908-0320 :))
Who can read/speak japanese?

Prices for Toho Player base Systems:

TM-10 (Technics) plinth weight 27kg, price 230 000 Yen
+TH-100 Arm base weight 5.9kg , price 88 000 Yen
and something called M-3, m4, m5, g23, g30, g41
(additional armboard?) starts from 12 000  to 68 000 Yen!

TC-20 (Denon) plinth weight 29kg, price 230 000 Yen
TV-30 (Victor) plinth weight 24kg, price 210 000 Yen
+TH-80 Arm base weight 7.6kg , price 33 000 Yen
and p23, p30, p41 (additional armboards?) for 6 800 Yen

If it was made in the 80s then the price is tough!
atmasphere's avatar
atmasphere
11,846 posts
 
In a typical cutting lathe is the cutting arm mounted on the same plinth as the platter or is it on a platform ?
The lathe platter and the cutter are mounted rigidly in the same assembly. Ours is made of cast-machined stainless! That assembly in turn resides on an anti-vibration platform which in turn rests on a table with adjustable pointed feet.

By having the cutter and platter rigidly coupled, vibration entering the system does not get cut onto the LP. The same principle must be applied in playback to insure a lack of coloration. Any deviation from this formula will result in -wait for it- deviation (of the stylus) and will result in coloration.

Whether that coloration is heard and accepted as such by the operator is another matter entirely!


sampsa55
73 posts
 
That TOHO stuff looks very interesting!

More info on TOHO:
https://audio16.com/2013/10/11/copernicus-was-right/
http:///audiocirc.com/2014/03/12/more-than-a-tonearm/
http://20cheaddatebase.web.fc2.com/needie/NDTOHO/TOHO.html
http://www.vinylengine.com/library/toho.shtml

Looks like they gave up on audio, but are still in business doing camera things.


halcro's avatar
halcro
2,664 posts
 
Interesting ToHo stuff.
I was aware of their tonearm pods (as Thuchan has one)...but I never saw their turntable cast-iron supports before.
Looks quite similar to my new support 👀
http://i.imgur.com/ddKNHVx.jpg
Interesting cutting lathe here
http://i.imgur.com/GB8oq5U.jpg
fleib
1,124 posts
 

***Now in a turntable how it plays out is that instead of being scary or dangerous, it works out as a coloration: the platter must be as tightly coupled to the plinth via its bearing as possible, in turn the plinth must be absolutely rigid and acoustically dead while coupling the platter bearing to the base of the arm (which in turn should have no play in its bearings). Any divergence from this formula results in coloration.

The reason is simple: if the platter has any other motion other than rotation (for example a slight up and down that might be imparted from the plinth due to room-borne vibration), if there is any difference between that and the base of the arm the cartridge will compensate (since the stylus has to stay in the groove) with stylus motion and therefore a coloration.

So if the arm is sitting on a separate structure from the plinth, it is open to motion in a different plane and/or frequency as opposed to the platter and plinth. You really want it to move in the same plane and frequency as the plinth so that whatever that motion is can't be interpreted by the cartridge.

I am often amazed at how poorly understood this concept is. ***


This concept is a gross oversimplification and isn't thought through.  Airborne vibrations will be imparted to the platter (record), plinth, and arm at roughly the same time. There will be a delay as these vibrations are then transmitted from one to the other. This results in additional smearing/coloration.  It could also result in greater amplitude and additional coloration.

This is not better. It's worse, assuming the pod approach is well done and resists cross coupling.  There will still be some cross coupling through the base, but it's less likely to produce cross coloration if the base resists vibration transmission and the pods are mass coupled.

It's a fallacy to assume that vibrations appearing at the main bearing are best transmitted to the arm.

***According to them the separate tonearm pillar version sounds more transparent and quieter because of the isolation of the tonearm from the TT.***

No good reason to assume this is false.

Regards, 



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