Cartridge Loading.....Part II

Ok guys, I'm getting dizzy.

@rauliruegas , I already have that test record!

Channel D has received my wire transfer ($500 credit) and A friend says the Platinum Signatures will arrive any day. I might also get an Ortofon Verisimo., teeter tottering on that one. Since I can run the phono stage 4 different ways and I can record records to the computer I will be able to make 192/24 files of all the results which I can download so everyone can judge for themselves as long as your system can play files. If not then GET WITH IT. Digital is hear to stay (spelling intended). It allows you to do cool things you can not do otherwise and share the results with friends. 

@rauliruegas  I have no idea what is better but I will figure it out and I will be happy to email you the files so you can compare. Then you can tell me!

@mijostyn  : " Digital is hear to stay .."

With out single dude. Good.

R.

For the record (if you see what I did there) I've never stated that loading a cartridge would cause mistracking! That is simply Raul with his usual logical fallacies again (in this case, the classic Strawman).

What I have stated is that loading the cartridge will cause the cantilever to become stiffer. This fact is unavoidable as anyone grounded in generator and alternator theory knows. This does not mean that the cartridge will mistrack. It means what I said: the cantilever will be stiffer; whether that affects the performance of the cartridge is another matter and other than suggesting that it might affect high frequency tracing ability. I've also been careful to not state what frequency, which may well be ultrasonic; at any rate obviously is an unknown.

Raul, in his on-going quest to simply make me wrong, has been trying to put words in my mouth. Fortunately I'm way to far away for him to actually do that 😁

@atmasphere 

I gave up when Raul confused cantilever material with cantilever motion ( see quote from Raul below ).

The reality is that any change of loading will possibly have an impact on "tracing the groove". The Shure white papers explain this clearly with their testing on groove tracing and the impact of changes in compliance - at worst they describe scrubbing motion of the stylus/cantilever from mismatched arms/cartridges. It is the genesis of the use of their stabiliser brush. Tracking tests on records do not measure distortion - they only indicate a tracking ability ( crudely ).

In my view there may be no obvious mistracking from altering the loading, but there is the possibility of a change in tracing and distortion ( for better or worse ). 

If Raul loads all MC at 100ohms, then likely he cannot hear the impact of changes in loading, or he has a low resolution system - or both.

As an aside I agree with JCarr's and your comments that loading is more about taming poor quality phono stages with poor overload margins at ultra high frequencies. Folk need to understand that, like brick wall filters in early digital, problems at ultrasonic frequencies can generate artefacts down into the audible region. Perhaps Rauls home brew preamp is in this group which would explain why he needs to load all MC's at 100ohms - which is extremely low - particularly for cartridges with an internal impedance above 5-6 ohms. It's no wonder that Raul thought for years that he preferred MM cartridges most of which have large phase shifts and frequency aberrations in the audible region - necessarily tuned by loading R & C of course in order to get a reasonable facsimile of a linear phase coherent response. 

I did it.Over the years participated in no less that 8 threads about cartridge loading here and wbf and in one of them I posted something as:

stifness of cantilever it's a good thing because cartridge designers normally looks for the stiffer cantilever material as Boron, higher stifness the better in favor of better quality level listening performance.

The distinction between virtual and actual ground is a subtle one.

When an opamp inverting input is used, the virtual ground is extremely similar to a real ground as the action of negative feedback makes it so. The difference is in the error term- i.e. the output voltage divided by the open loop gain of the amplifier, together with any impairments added by the amplification system.

This difference can be extraordinarily small, so arguing that the virtual ground is not a real ground is largely facile. 

As far as the source is concerned there can be essentially negligible difference between a real ground and a virtual ground.

Claiming, arbitrarily, that it is prima facie audibly different as far as the source is concerned is not reasonable. 

@wynpalmer4 The virtual ground is one thing when it is driven by a resistance in series with the input (which might be a cartridge). Its a bit different when the cartridge itself is that resistance. WRT actual ground, I think we can both agree that a cartridge driving a dead short will not produce anything that can be amplified. A virtual ground is different in that manner 😉

One thing that has come up in this thread is the mention of Lenz's Law, which has to do with the radiation of a magnetic field from a conductor when conducting. Its been brought up in the context of 'back EMF'. I've not been able to discern how this is supposed to work; if driving a loudspeaker (which has significant inductance interacting with a magnetic field) you do get back EMF but in the case of the cartridge an impedance (for the most part) very little inductance in the load is present. So I would appreciate an explanation; as best I can make out the back EMF would be insignificant WRT the source.