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Damping the analogue "setup"

Friends,
I am fighting this issue for the last 1 year or so with my TT setup. I am a beginner in analogue playback but I use some decent equipments to play music. My setup is:
Nouvelle Platine Verdier
Naim ARO Tonearm
Lyra Skala cartridge
RCM Sensor Prelude phonostage

All the equipments are placed on wooden rack (made of Ebony) with spikes. The problem is, the overall sound can vary vastly from lean-strident to round-warm very quickly based on what kind of spike base I use underneath the rack. A typical metal (aluminium, steel, brass) spike base makes the sound lean and fast to an extent where it really bites. Whereas using a softer metal (cast iron) or rubbery/woody substance below the rack makes for a slow and boring sound.

It is not just the turntable that reacts so severely but also the phonostage. Placing the phonostage on a softer or a more damped isolation footer immediately reduces the grit in the sound. I do not hear such drastic reactions from my preamp or power amp. My guess is, the complete analog front end needs some level of damping. How do you go about it ? How do you choose the platform that will support the turntable setup firmly so that the sound doesnt lose its energy but still damp it adequately ?

For the moment (thankfully) my ARO is an un-damped unipivot designed to work without any damping fluid.
pani

Showing 6 responses by halcro

halcro's avatar
halcro
2,664 posts
 
The short sweet answer is.......get the turntable off the floor and onto a wall-mounted shelf.
The structure-borne feedback in the suspended floor will continue to haunt you if you dally with stands, spikes, feet etc.
halcro's avatar
halcro
2,664 posts
 
Is your concrete floor on the ground or is there a room under it?
If it's not on the ground.....it is suspended.
Having a timber floor on top of the concrete can introduce many of the problems of suspended floors as well.
halcro's avatar
halcro
2,664 posts
 
I assumed it is not such a serious issue.
It is a most serious issue......
We have found that suspended concrete floors have intense inbuilt stresses because of the spans......and these stresses cause lower ever-present Structure-Borne sound than those present in suspended timber floors.
Modern high-rise apartment buildings are particularly susceptible because of the prevalent use of prestressed concrete floor slabs which allow for thinner thicknesses and less steel reinforcement.....but also permit greater movements, bounce and structure-borne sound between 2 Hz-10 Hz.
These frequencies are almost impossible to eliminate from floor-mounted stands and that is why your turntable and phonostage are sounding differently with each and every change in support material.
halcro's avatar
halcro
2,664 posts
 
Pani,
If you can find a concrete wall or column in your listening room......then you can mount a support shelf for the turntable.
The columns and supporting walls are not subject to the spanning stresses that the suspended floors are and thus do not carry the same low frequencies within.
halcro's avatar
halcro
2,664 posts
 
Seriously, a bowling ball on top of my washer or dryer provides a similar benefit.
Now there's an idea.....
Perhaps a cricket ball on top of the turntable will solve all structure-borne feedback problems?
halcro's avatar
halcro
2,664 posts
 
There is one problem with the use of ‘sand boxes’.
Their perceived benefit is not the sand itself….but the ‘voids’ between the sand.
In other words…..full sound transmission through the sand is hampered by the ‘air’ between the individual sand pellets.
Now initially this may work to some extent….but sand has a propensity to ‘compact’ due to gravity, heat, moisture, load and time and many of the ‘voids’ become smaller and tighter and many disappear altogether thus obviating the initial benefits.
When sand becomes fully compacted……its density approaches that of concrete. In fact before the discovery of cement…..compacted sand was used as a base for laying glass mosaics and with the discovery of volcanic ash and pumice by the Minoans, Greeks and then the Romans…..the addition of Pozzolanic lime to fill the voids in the sand mix together with water created the first ‘mortar’ and then concrete.
Even today…..a compacted mix of 10:1 sand to cement (to fill the voids) can often be used to bed brick, concrete and stone paving.
As there is no really successful method for preventing the slow but inevitable compaction of the sand within a sand box…….its efficacy will slowly deteriorate to become virtually zero.
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