2. analog
  3. 124260-369

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
lewm
12,524 posts
 
Dear Fleib, I cannot resist commenting on your penultimate post, dated 05/05 at 8:51 PM.  A suspended plinth is not a "different story"; it is the same story, except in the case of a suspended plinth vs a stationary discrete arm pod, it is plain for you and me to see WHY the discrete arm pod is not a good idea.  To wit, there would be a great deal of movement of the LP surface, mediated by the suspension, that could not be followed by movement of the tonearm pivot, and this would generate spurious signals at the cartridge/LP interface. On a more micro level, this principle is operative in the relationship between any plinth, suspended or not, and any arm mounting system.

fleib
1,124 posts
 

Lew, That's BS for reasons already stated. Micro vibrations wouldn't make it from record or main bearing to the arm, with a massive plinth. With a flimsier plinth the movement of platter and arm must coincide perfectly for this principle to be valid, and that is not the case when vibrations originating from the platter are transmitted through the bearing, then the plinth and to the arm base.  Surely you jest.

Regards,

atmasphere's avatar
atmasphere
11,615 posts
 

A table with a suspension is a different story.

A suspension is irrelevant. The rigidity of the plinth is what is important. 


Unless that means something other than what it says, you're changing your story.

My 'story' has been 100% consistent through this debacle. However I suspect that my prior posts have not been read very well, or they have been interpreted in some way I could not predict.

To be clear here, the noise in our mastering environment is airborne. The vacuum system sits in a box (to suppress noise) at the other end of a rather long hose.

I understand your engineering principle, but I question the significance. Will a massive plinth transmit small main bearing movement to the arm base? Excite a tuning fork and touch it to a big rock and the vibration is turned to heat. Even if it does transmit it, the resultant arm movement will occur after the main bearing event.

You say you understand this basic engineering principle (not mine by any means BTW), but the rest of the paragraphs contradicts that statement. So I think that the first statement must be false.

FWIW, I think we can be unconcerned about the bearing noise in this conversation (although I do think its important), unless the bearing chosen has serious problems! Even the bearing system employed on a lowly 1970s BSR is relatively quiet and not a source of trouble unless it is damaged or in need of maintenance. Modern turntable bearings are usually pretty good (although I have seen some wankers in some +$20K machines, worse than those BSR bearings I just mentioned but likely that is a topic for another thread). So the real issue is airborne and structural borne vibration, which I have maintained since the inception of this thread. If you don't get that, then you've not been actually reading my posts. 

What about micro movements you allude to? Not likely, and with the same time consideration.

Sound pressure waves hitting the platter are also hitting the plinth and arm at virtually the same time. To say that a plinth will insure coincidental movement between cartridge and record also doesn't make sense with regard to time. The impact on the record player is instantaneous and rotation of the record is continuous.

If you don't understand the bit about micro movements here, then my supposition that you don't understand the basic engineering principle is confirmed. You might want to have a conversation with a mechanical engineer whilst maintaining an open mind.

If you look at your second paragraph here, obviously you understand the problem, and then like Raul did a few posts above (see 'My God!') arrive at a false conclusion not supported by logic. I find it perplexing- so I have to assume that an agenda is underlying this that causes you to veer away from what seems a rather obvious solution. BTW, the fact of the platter rotating has nothing to do with this! Again, we discovered the problem and made measurements that confirmed it; it seems that those that are proponents of arm pillars have no measurements whatsoever.


lewm
12,524 posts
 
Flieb, Exactly what part of what I wrote, specifically, is BS?  Would you use an outboard arm pod with a suspended turntable? I don't think so. You are arguing specifics (it might not work well because of this or that), and I am talking about the ideal goal.  As I also said somewhere further up the thread, the engineering problem is to make the tonearm/platter behave together.  I never said that was easy to do, but that should be the goal.  If you mount the tonearm on a separate structure, then you have abandoned hope of achieving that goal, or at the very least, you've made it more difficult than it needs to be.  Certainly, there are subpar executions of the integrated turntable/tonearm paradigm; that's one reason why turntables sound different from one another.
terry9
2,239 posts
 
I propose that Ralph be enrolled on the calendar of saints. His restraint is supernatural - a miracle thrice renewed!!

More to discover