HiFi Subjectivist ¦ Audio Forum ¦ NVA User Group

karatestu wrote: ↑Tue Jan 17, 2023 3:02 pm I know this is from the manufacturer but here is what it says about cartridge life and suspension under exchange/rebuild. You may need to zoom in a bit.

NSNO2021 wrote: ↑Tue Jan 17, 2023 3:56 pm Copied directly from the Sumiko website, see https://sumikophonocartridges.com/what- ... cartridge/

So not theory but empirical and from a dedicated cartridge design and manufacturing company with 40 years experience of the subject matter. Hopefully thats enough evidence.


Suspension

A phono cartridge suspension is like the gatekeeper to success in a phono cartridge. The suspension is typically made with a compliant elastomer material that allows the cantilever to move freely in the dimensions the stylus requires, but also acts to damp resonance coming from the cantilever. It also to stave off micro jitters of stylus in the record groove, and holds the cantilever in its proper place relative to the generator. How much it moves is measure in ‘cu’ (compliance units). It is expressed as a number that looks like this: 10-6cm/dyne@100Hz, or in everyday speak, 10cu. The higher the first number, the more compliant the suspension. The lower the number, the stiffer the suspension (less compliant). The suspension is typically positioned along the cantilever so that it defines the pivot point of the cantilever assembly, and is located much closer to the generator than to the stylus. If designed incorrectly (too stiff, not stiff enough, too much rebound, too long a memory, or treated incorrectly), sound quality as well as stylus/record life will be negatively impacted. Tracking force and even room temperature are further considerations for a properly performing suspension. A correctly designed and applied suspension system perpetuates a stylus that can smoothly and effortlessly follow the record groove, allowing the moving structure at the opposite end of the stylus to interact with the generator in a uniform way. As the suspension is typically made from a variety of rubber, it is susceptible to degradation over time due to shear use, but also due to environmental conditions. A suspension system in a hot and humid environment will not last as long as one in a mild climate, just as a cartridge in a very hot and dry climate will also be adversely affected. If the turntable is in direct sunlight, it will shorten the life. Advances in materials over the years have provided more robust rubber compounds that hold up better, but the very small amount of material relative to the amount of vibrational energy it deals in makes for a very difficult design brief for engineers. In terms of performance, a consistent ambient temperature is the single greatest key to getting a consistently great result from a properly set up phono cartridge. Some audiophiles even place a lamp near the turntable to control the ambient temperature for the
cartridge, and many even keep a temperature gauge nearby. For practical purposes, a suspension too cold is not sufficiently compliant, a suspension too warm is excessively compliant.

karatestu wrote: ↑Tue Jan 17, 2023 5:08 pm It mentions shorter lifespan in hot and humid and hot and dry climates. Mine has been stored in a cupboard in an unheated bedroom of a 16th century solid stone farmhouse which stayed remarkably cool in that 40 degree heat we had in July. Even when I used it that was never in direct sunlight .

savvypaul wrote: ↑Tue Jan 17, 2023 7:07 pm Cartridges can be replaced.

I'm not so sure about record collections...