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Tonearm microphonics

When I have the volume at my normal level & tap the arm (not whilst playing vinyl) it is slightly amplified... Is it possible to significantly reduce/eliminate this?

Current set up - Roksan Xerxes 20plus, Origin Live Encounter tonearm (thin cork ring at the base) with Lyra Skala.

Apologies if this is a stupid question!
infection

Showing 3 responses by larryi

larryi
4,256 posts
 
If an arm is not stiff enough and/or it does not have enough self damping (does not effectivelyt dissipate the energy of its vibration as heat), the vibrations imparted by the cartridge will feed back excessively to the cartridge and this will affect the sound.  That is why, designers try hard to maximize stiffness and internal damping within the constraints of having to keep the arm from being too massive.

But, theory aside, not everyone likes the sound of those arms that maximize both stiffness and damping.  I have not heard it, but, a friend heard the SAT tonearm (exraordinarily stiff and damped) and thought it sounded a bit too clinical and lifeless.  Some tonearm manufacturers offer an assortment of different materials used in the tonearm shaft to tune the particular resonance of the arm to a particular cartridge or personal preference of the owner (e.g., Shroeder).

If you have ever played with liquid damping of tonearms (changing the level of fluid in a damping trough on an SME or the level in the bearing cup of an arm like the Basis Vector), it is quite easy to hear how changing the amount of damping affects the sound.  It is hardly the case that maximizing damping results in the best sound.

I know a lot of people would like improvement in audio to be a simple case of increase this or decrease that, but, it is actually far more complex than that.  So much of it involves "tuning" and matching things in a complementary fashion and making the right compromises.  
larryi
4,256 posts
 

bdp24,

Yes, I do think it is possible to overdo damping.  Specifically with tonearms, I have experimented with the damping fluid level in my Basis Vector arm and heard the difference with the fluid level in the damping trough of an SME arm.  Too much damping results in a lifeless sound. 

I think tuning of resonance and damping of vibrations in all parts of the reproduction chain is NOT a matter of trying to minimize vibration to the utmost.  I was in attendance when a representative from Symposium tried different shelves under a CD player.  The very top model that Symposium offered, that does the most to dissipate vibrations as heat, actually sounded quite bad--dry and thin.  The representative agreed with this assessment; there can be too much damping.

I've heard the same with devices for placing under speakers, exotic racks, etc.  I spoke with someone in the high end industry that has heard hundreds of different systems.  He said that he has NEVER liked the sound of a system employing exotic and extremely expensive vibration damping rack/shelves.

larryi
4,256 posts
 

If I understand how viscous damping works, resistance increases with velocity of movement.  As an example, if you put your hand in water and move it very slowly, there is very little resistance to movement.  But, try to move it fast, and the resistance increases dramatically.  When a tone arm has to make large lateral movements (e.g., off center record) , it is forced to move at a much higher velocity than its normal movement, which is quite slow.  I don't know if this added resistance is enough to create excessive strain on the cantilever or the suspension, but, I would guess that fluid damping is not a help in these situations. 

But, some resistance to movement laterally might be a help when it comes to bass response.  Deep bass is often cut monophonically so that all of the movement is laterally.  If the movement is large enough, the whole arm will move instead of the arm being held steady (stead would mean all of the movement of the cantilever is translated into signal).  Thus, movement of the arm to follow the groove results in reduced bass response.  If damping helps to resist such movement, bass response would be more powerful and faithful to the signal on the record.  The Moerch DP9 anisotropic arm does this by increasing the effective mass of the arm in the lateral plane of movement; I bet damping would provide similar resistance as well.

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