Tonearm mount on the plinth or on Pillar ?

Halcro, you ask if I run OTL. Well, I did, and they sounded fine, but I decided on home brew, where cost is less of an object. Before building anything, I decided to optimize the system (instead of the pieces thereof), and found that I could improve system performance by using solid state Class A, push-pull, with low voltage rails, which allowed me to safely remove the now-redundant protection circuits from the ESL's.

Amps better than OTL? Don't know - but the system sure is.

If you think air borne vibration is not a problem you are up against the issue of the real world. No matter how dead you think a thing might be, it will always have some motion, some vibration.

This is an uneducated assumption.
Most people follow this belief but if you had studied acoustics and the science of materials, you would know that materials react to air-borne sound by a mixture of:-

• Reflection
  
• Absorption (as heat)
  
• Transmission (passing directly through)
  

It is only when sound pressure of a sufficient volume (and that's important) at a material's Resonant Frequency occurs...that the material can 'vibrate'.
You do know of course that the Resonant Frequency of most tonearm/cartridge combinations is 6-15 Hz and this is well below the frequency reproduction ability of all commercial loudspeakers and almost all subwoofers as well?
It in only in this frequency band that any vibration of the tonearm/cartridge can be observed. There is no 'alternate' vibration phenomena unless you can direct us to the relevant scientific papers?
For the heavier plinth and platter components of the turntable system, a resonant frequency in the order of 2-6 Hz may apply.
You seem to use the term 'vibrate' as if somehow it were a different genus to 'resonate'?
Not only is your understanding of air-borne sound transmission and vibration factually inaccurate, it is logically impossible.
Were it true....every increase in the volume dial would degrade the sound.
Let me repeat that....
If air-borne sound pressure is a problem in the turntable playback system, then every increase in volume would of necessity degrade the sound.
Now there are many out there who will exclaim that this is indeed the case with their systems but as I explained previously...they are hearing the effects of structure-borne feedback...AMPLIFIED.
There are tens of millions of turntable systems where turning up the volume is heard to IMPROVE the sound quality noticeably.

Halcro


"It is only when sound pressure of a sufficient volume (and that's important) at a material's Resonant Frequency occurs...that the material can 'vibrate'."

I want to be sure that I have interpreted your statement here accurately.

What you are saying is this....A material will NOT vibrate as a result of acoustical excitation unless that acoustical excitation is at the resonant frequency of the material and that this acoustical excitation is of sufficient energy.

Is this a correct summation of what you just posted?

Cheers. 

Halcro
Further expansion of my last question....
Are you saying that, with accoustical excitation, the material will ONLY vibrate if the excitation frequency is the resonant frequency of the material?

IOW. Accoustical excitation at frequencies other than the materials resonant frequency will result in NO vibration in the material, regardless of the energy level of this excitation?

cheers.