Cartridge loading

Dear @lewm  :  I understand what you move to post about and I know you that almost always you try to give and explanation/your explanation and this is fine.

Now, I posted that I know that exist no one that can " jump " with true evidence of that " limit trace ability on HF " and I know because in that older thread where I participated where the kind of gentlemans that have a really high technical knowledge levels and rigth there one of them proved to atmasphere that what he said about was and is: false and atmasphere just left with out answer or evidence on the issue, as a fact he stay " dead silence ".

Just like here when I asked to him a precise question to rpove what he is spreading any where for many years and he do that even that was proved to him that is: false.

I that thread no other persons " jump " to shows evidence to confirm that that assumption was not false.

My technical level is very low and that's why I still ask to him for evidence on that " limit trace.."  that like intactaudio I know just does not happens.

I know that you agree that can't happens and that's why you are looking for that " jumping person "  that you posted.

Of course that like you I will love that that person appearead here to tell us that we are wrong and that that " limit trace..." exist and he shows the evidence.

But due to whom is atmasphere and his cotinuos spreading on that issue and with all respect he has the responsability to show that true/live evidence or accept is a misunderstood from his part. He can do the last mantaining his " dead silence " attitude that is a confirmation of no evidence.

The issue/problem is that " limit trace..." I hope he can come back with the evidence where ( I hope ) we can duplicate in our system and be aware about.

R.

Hey Dave (Intactaudio), .001 ohms is still not zero ohms.  I'm just sayin'...But I'm also impressed.  That unit can do the purest "current gain" of any I know about so far.
And, since Chakster can move at light speed, rules fall apart.

Raul, I share your interest in this subject.  But I also know that Intactaudio is one of the smartest guys in the business, even including the persons you have in mind, and I know that he is still thinking on this subject of the effect of load on the motion of the stylus.  I see it as a very complex question, but maybe that is because I myself am so lacking in understanding.  However, as I understand you, your position is that it doesn't happen, because you can't hear it (and because you have the testimony of some other knowledgeable persons who also deny the phenomenon exists).  Is that a fair summation of your position?

Chak, Is THIS what you have?https://audiocubes.com/products/47-laboratory-4712-phonocube

What I experienced always is that at 100 ohms quality level cartridge performance is always better

If your phono section has RFI sensitivity what you state above will be the case as I’ve maintained also on these threads.


With regards to the load impedance affecting the cartridge, of course this happens. Moving coil cartridges work on the same principle as a loudspeaker; now think about a kid’s walkie-talkie that has the speaker also double as a microphone. In other words, the speaker can be driven by energy or it can make energy, because it is a **transducer**, and with any transducer motion is converted to electrical energy and vice-versa.


You can test this easily enough- remove the grill from your speaker and see how easy it is to move the woofer if nothing is attached to the speaker terminals. Then short out the speaker terminals and see how easy the woofer is to move then! With a cartridge its no different- the more you load it down (lower resistance loading resistor) the more work it will have to do and so the cantilever will be harder to move. Since this is also the idea of ’damping’ we can easily infer that mechanical damping of the cartridge will occur if the load impedance is reduced.


Anyone schooled in the electrical arts will understand this immediately; and thus also that high frequency output of the cartridge will be reduced as the cantilever is made to do more work. If this is not readily apparently please do more study of electrical theory.


Now there is one exception with regards to the input impedance of the phono circuit- the load impedance must be connected to the cartridge in such a way that it causes it to do more *work*. If the cartridge is not doing any work then it will be unaffected. Now refer to the article at this link previously given:
http://phonoclone.com/diy-pho4.html

We can see that the cartridge is actually being loaded by the input of the opamp; which if measured will be found to be quite high (most modern opamps are FET input). The idea is to replace the input resistor with the cartridge itself- so that the virtual ground (present in any opamp circuit) is the output of the cartridge itself. In this circuit the cartridge isn’t doing the sort of work as it would be if the cartridge were presented with an actual 0 ohms impedance!! IOW, zero ohms and *virtual ground* are not exactly the same thing! I refer you to OPAMP theory 101 as to why. As a hint, the closer the gain of the opamp is in open loop to infinity, the more the virtual ground will behave as it it is zero ohms **as far as the opamp is concerned**. This is more of a control theory thing which is far more text than I have time to put here, especially since you’ll need an EE degree to follow along. Just take it for now that a virtual ground isn’t the same thing as actual ground or zero ohms! If it were, no amplification could occur!

@lewm

Is THIS what you have?https://audiocubes.com/products/47-laboratory-4712-phonocube

Yes, it doesn’t work without special power supply, so there must be a power humpty (first in the list) and i have it with my phonocube.

If you’re buyin’ a Phonocube without power supply it looks like a good deal, but it doesn’t work. The power supply is 3 times bigger than the cube itself and superheavy. For superb results some people use 2 power supplies for 1 Phonocube (dual mono).

More images of this set with power supply and cube are all HERE (not mine).

And you can study about parts and its unique but very simple circuit HERE.
Let me know what you think now when that guy cracked it and explained why the input impedance is almost ZERO. But that guy is not the designer of the Phonocube, he just made a clone.

P.S. I think i posted all these in another thread long time ago.
The PhonoCube originally designed for Miyabi 47 Lab cartridge. 

Which current injection phono stage do you use ?