Is it time for some clothes.....ππβ
Five years ago I went nude...but don't tell my kids...
Three years ago I went nuder...kind of 'Punk Mad Max'....
Sound was good. Inspired some fellow converts and adherents but a small problem arose.
Whilst my solid cast bronze armpods at 25lbs each would never move......the rather lightweight cradle could often be nudged in the process of cartridge swapping and the spikes could slide along the hard laminate on the cantilevered wall shelf..π©
Tired of re-checking the alignments of three arms, I decided to drill through the laminate at the positions of the three spikes to prevent any further sliding.
Mission accomplished but small problem now became BIG problem..π
The tips of the spikes now made contact with the shelf substrate and its inherent stresses. These subsonic tensile stresses now induced a resonant frequency response in the stainless steel cradle which transferred to the platter/record interface and could be amplified by the stationary stylus at maximum volume settings.
Most turntable designs deal with structure-borne feedback in a combination of various methods with mixed results.
Suspending the plinth on springs or trying to isolate it with rubber or other compliant feet or various types of air-inflated supports is one method.
Mass is another. Real mass is still another...
I have chosen to try a 'mass' solution...π
The idea behind the 'mass' approach is the hope that physical vibrations can be absorbed and dissipated as heat within the plinth/platter instead of allowing resonant response characteristics.
Sometimes this works and sometimes not....
With the space restrictions of my 'nude' setup I can only create a cylinder of either granite or gunmetal/bronze (wood is simply not massive enough in this small structure).
Bronze would weigh 3 times more than granite (19Kg vs 7Kg) but also costs 3 times more...π²
So at this time....somewhere in China, there is a CNC machine routing and polishing my turntable 'plinth' cylinder out of a solid block of black granite..π
Gosh I hope it works.....
Five years ago I went nude...but don't tell my kids...
Three years ago I went nuder...kind of 'Punk Mad Max'....
Sound was good. Inspired some fellow converts and adherents but a small problem arose.
Whilst my solid cast bronze armpods at 25lbs each would never move......the rather lightweight cradle could often be nudged in the process of cartridge swapping and the spikes could slide along the hard laminate on the cantilevered wall shelf..π©
Tired of re-checking the alignments of three arms, I decided to drill through the laminate at the positions of the three spikes to prevent any further sliding.
Mission accomplished but small problem now became BIG problem..π
The tips of the spikes now made contact with the shelf substrate and its inherent stresses. These subsonic tensile stresses now induced a resonant frequency response in the stainless steel cradle which transferred to the platter/record interface and could be amplified by the stationary stylus at maximum volume settings.
Most turntable designs deal with structure-borne feedback in a combination of various methods with mixed results.
Suspending the plinth on springs or trying to isolate it with rubber or other compliant feet or various types of air-inflated supports is one method.
Mass is another. Real mass is still another...
I have chosen to try a 'mass' solution...π
The idea behind the 'mass' approach is the hope that physical vibrations can be absorbed and dissipated as heat within the plinth/platter instead of allowing resonant response characteristics.
Sometimes this works and sometimes not....
With the space restrictions of my 'nude' setup I can only create a cylinder of either granite or gunmetal/bronze (wood is simply not massive enough in this small structure).
Bronze would weigh 3 times more than granite (19Kg vs 7Kg) but also costs 3 times more...π²
So at this time....somewhere in China, there is a CNC machine routing and polishing my turntable 'plinth' cylinder out of a solid block of black granite..π
Gosh I hope it works.....