Cartridge burn-in

I took a rebuilt Cart' to a friend, to use in their system and compare to their owned Cart'.

My friends Cart' was with a decent period of usage hours and was a model that was from the upper range of what the Brand offers.

My own Cart's was a lower down the range model but bespoke produced through a rebuild.

The interest was to see where these two Cart's were in comparison to each other.

I distinctly recollect the first visit with 20+ hours of usage on my owned model, the Bass was not quite gathered and not quite able to create a perception of believable envelope for notes from the lower frequencies.

At a visit with about 150ish hours of usage, my Cart' was to my assessment a much-improved performer in the Bass region and a very good comparison to the friends Cart'. I also distinctly recollect upper mid and top frequencies were projected further and detail retrieval from the Groove was more evident.

I was not wanting much more and was not pining for anything else that been heard during the demonstrations. 

Improvement was expected to be discovered after a period of Break In, that was the general overview, and not too different from contributions from other posts within this thread. 

Improvement was discovered to be occurring, but the unexpected was for it to become an improvement to the point it compared very favourably to another rated model, this was not anticipated to end up as such a close call. 

To get to this point, it was only important to use the Cartridge in a very careful manner. 

It has been a while since I have put a New Built Cartridge into my system and almost twice as long since I put an 'off the shelf' design New Cart' into my system.

Prior to the New Built Cart' I was using a SS Phonostage and Hybrid Valve Phonostage. Since the New Built Cart' has been added, it is working mainly with Valve Input/Output  Phonostage.

When using a New Cart' and assessing it, I recollect the Valves would 'Pop' to their prime performance quite noticeably after a period of use, and the Cart' would continue to show subtle changes towards what was to be the prime performance, from recollection it was the lower frequencies that were becoming more gathered and real in the capable of doing it right area.

I don't recollect the Cart' going backwards as the usage progressed, when the Valves 'Popped' the Cart' always seemed to be very close to the last recollected bass performance.

It was a later experience of demonstrating the Cart' in comparison to another Higher Up the Range Model from the same Brand, using the same Headshell>Tonearm>TT and HiFi System, that really showed how improved the Rebuilt Cart' had become.    

The only item in the assembly that is looking likely to need to show a change that is perceived as adding an improvement through the change is the Material used for Damper.

A Change to the Stylus is potentially wear only and this will be deemed detrimental as it progresses.

The Cantilever and Pivot are certainly not parts belonging to the assembly that would be wanted to change their inherent properties.

The Damper is a material that is a Compound of materials that will ultimately become a Type of Rubber, the constituents/formulations will vary to produce the Rubber Compound. Designers will select a substance that in many cases will be a unique material, that satisfies the designers need for the elastic and viscous properties of the material, and possibly the known environmental effect on the Compound.

The Rubber Compound selected as the Part, can have a multiple of ingredients and these can vary in the parts added per 100 parts of rubber. The final selection of the Rubber Compound and effects on the Compound of the added Elastomers will undoubtedly produce a Part, when selected that is to have a multifunction role.

One such role which will be for the managing of vibration will be best served from a Compound that has the correct Static and Dynamic Properties engineered into the Rubber Compound. Knowing such information will be critical in the selection process.

It does seem that a Damper is to change its properties through usage and possibly time. It does seem a most likely Damper Selection will be limited to a selected few, who will be qualified in making the choices for these changing in properties materials. 

It does seem a Damper has the potential to be impacted on by the environment it resides in, and through usage can change. It also seems likely a Damper that has been exposed to the environment/working environment for a long period can possibly undergo changes that become detrimental to the Cartridges performance. The question is do Dampers from a production have a uniform property or is there variances across samples, or is there Dampers used that might already be affected by the environment they are kept in. Is this a possibility a Quality Control issue and is contributing to the differences reported for Break In times. 

It is possibly a selection of a Damper Material, that is one, that can make or break a Design and how it is received in the Market Place, so a very big responsibility to get it correct for the end user. Keeping a Damper material as stock item for an extended period in a particular environment might have an effect on the material and change the performance of product as it produced over a period of time.

The Suspension is one I am not sure of, it is known to change its properties through usage, but I am not sure where the detriment to the overall performance manifests due to these changes. It is not uncommon to see a report where a Suspension required re-tensioning, the question is does the tensioning vary between models when new. Is this a quality control issue and can possibility be contributing to the differences reported for Break In times. 

Rubber Compounds are not a predictable material, the environments these are exposed to will impact on the Elastomers properties.

In general, there is a reaction to ambient temperature, if cold the Rubber Compound will reduce in compliance and could be a Hard Substance, alternatively the ambient Temperature being hot, can cause the Rubber Compound to soften, possibly to the point of being too compliant.

The relationship between the Rubber Compound and how it functions as a compliant elastomer, at an interface between the cantilever/generator, especially for allowing freedom of movement for the envelope of dimensions the stylus requires, is critical to the overall performance and designed in qualities for the Cartridge.

The Rubber Compound as said will be multipurpose in function and will manage Vibration being met from varying sources. Resonance coming from the cantilever, is just one. When a Rubber Compound used a Damper is in an environment that enables the Elastomer Properties to be at their optimum, it also serves to be a preventative for the production off micro jitters from the stylus when in contact with the LP. The Rubber Compound functioning as a Damper will also position the cantilever in its proper place, in relation to the optimised interface with the generator.

The Compliance of the Elastomer is measured (compliance units).

Compliance Units is a mathematical equation and is also to be combined with ambient temperature of the environment, as the 'CU' calculation for Rubber Compound with Elastomer Properties is dependent on ambient conditions to apply a standardisation for the equation. One would like to believe when having information like this made known, that the Manufacturer is choosing an Elastomer Property that is falling into the middle area of Temperatures that are expected to be encountered, or the reality is maybe they are not. Maybe they are using a material that yielded the best for the design in a chosen temperature used for testing the design. 

 Revisiting the Tension Wire, that is in general a part used on MC cartridges only. – A typical configuration for the attaching of the Tension Wire is to attach to the Coil local to the Damper at the generator end, and also attach the Wire to the Cantilever local to the Damper.

The Tension Wire can be pulled to create a tension of the coil assembly against the Damper Elastomer. The selection of tension applied, is critical for controlling the activation of the suspension in relation to the mass and tracking force of the cartridge. This adjustment is a critical adjustment when building the cartridge, it may even define the uniqueness of a particular Cartridge from a particular Model within a Brands range of Models.

If the tensioning is dependent on the compliance of the Damper Elastomer, then the tensioning is also dependent on ambient temperature, and if this is not of the correct Celsius, it is most likely the critical parts are not performing in their optimised condition and the mechanical interface of the critical components is also compromised.

It is not too difficult to achieve a consistent Temperature at the location where the Cartridge is in contact with a LP, it is also not too difficult to create an easy to change Temperature between 10 - 30 Degrees Celsius to learn where the critical items might appear to be at their optimised. 

There is more to consider than the accuracy of the electronic interfacing for a Cartridge to an amplification and the Cartridge > Arm Matching. Either of these are standardised and not a concealed science, so these are most likely the least of the concern, when attempting to achieve an overall optimised set up. Creating the optimised environment for the Critical Parts that enable the Cartridge to function, that takes a little more wizardry.    

Unfortunately, I don't see a Manufacturer revealing the 'Dyne Calculation' for the 'CU' of the Elastomer or inform on the optimised ambient environment, there might be a little too much 'IP' in that as reveal.

If of interest the above does possibly share a Place with Car Tyres and their Compounds Elastomer Properties.    

All the more reason why the ambient environment that enables these Elastomer Compounds to Damp at the optimised function for the chosen material, would be best if made known by the manufacturer.

Most importantly is that the Micro Jitters produced within the Groove are not being prevented to manifest to the most effective measure when the Elastomer Compound is not optimised through functioning in the ideal ambient environment.

The idea of having a Cart' costing Multi Thousands, that is Compliance Matched, Load Matched and then left to the chosen ambient by the user does not make sense, unless the chosen ambient is carefully worked out to be perceived as the best for the Cartridge in use. 

There is the potential for a poor Cart' performance, when the mechanical interface and mechanical operation of the Cart', is used in an ambient environment that is not ideal. It is a worthwhile venture to be confident the critical materials selected and the chosen settings for the relationship between the materials at the interfaces are at their optimised for the function intended through design.

As the TT>Tonearm>Cartridge is one Trilogy to have optimised for the overall replay of a Vinyl LP.

The not too commonly referred to Trilogy of Compliance>Loading>Ambient Environment has a place to ensure the LP produced signal is not compromised by the failings of the Damper and Damper Tensioning interface.