Cartridge Impedance


I just bought a phono pre-amp that allows me to adjust the impedance of a MC cartridge. I was using 100ohms. Now I want to experiment.
Could someone tell me the effect the trebles will have if I lower or raise the suggested impedance. For example, If I raise the impedance will the highs be more prominent or less prominent? 
Thank you.
128x128jmh128
@rauliruegas

The OP is talking about loading his cartridge at his phono stage. When you post, "LOMC cartridges are not sensitive to load impedance, are sensitive to inductance changes," you imply that impedance does not affect the sound. That is incorrect.

Perhaps you meant to say, "It is the preamp, not the cartridge which is sensitive to impedance." That statement would be true, but irrelevant, as the OP wants to know how to set up his system. Compare your statements to those of Lewm and Atmasphere, who contribute to the discussion by explaining the technical details as well as addressing the OP’s point.
Dear @terry9 : "" and whom react to load impedance in reality is not the LOMC but the phono stage performance. """

That’s what I posted.


""" and makes it stiffer, less able to track higher frequencies. """

that’s not proved, it’s theory. In a normal designed phono stage you can test the MC 2000 LOMC cartridge by Ortofon that has really good tracking abilities and changing load impedances you just can’t detect " less able to track higher frequencies ". For this could happens you need that a cartridge with over 30cu goes down to 6cu ( stiffer. ) and that just can´t be happened because a normal load impedance changes. Just common sense.

Btw, the OP says: """ I just bought a phono pre-amp that allows me to adjust the impedance of a MC cartridge. I was using 100ohms. Now I want to experiment. """

what he need is to experiment with because you or me or any one else here know exactly that phono stage circuit design.

Against that reality, all our posts are irrelevant because all of us own different phono stages and room/systems. Useless, he needs to has first hand experiences and that’s all:  he has in the OP the response. My bad explanation and other only can makes that this Agon new comer can have a mix up: maybe not, who knows?.

Testing is the name of the OP game.

R.


Hey guys, as the original poster I just want to say, "calm down"! In my original post, I made the error of saying I wanted to change the impedance of the cartridge. I meant I wanted to change the impedance setting on my phono stage, knowing that the response of the cartridge would change. Some of you understood that. And yes, I just want to know how to set up my system. I don’t give a rat’s tush about all the other stuff! It was a simple question and the first 3 responses told me exactly what I needed to know.
I’m not a regular poster here, but I do read a lot of things with interest. But one of the things I’ve found is that when someone asks a pretty straightforward question, the discussion quickly degenerates into a lot of things that are irrelevant. I’ve seen someone ask, "Am thinking of buying only either cartridge X or Y. Any recommendations?" Then someone will say, "I’ve not owned either, but you should try cartridge Z." I mean, WTF! All he wanted was a straight answer. Ok, end of rant and thanks to those of you who answered my question directly and maybe threw in some USEFUL information.
Yes, testing is the name of the OP game!
You've got three electrical parameters going on here to consider: Impedance (which depends on frequency), capacitance (from the phono cable to the preamp), and inductance from the MC coils. 

The combination effectively forms a broad band-pass filter. 

You indicate you can adjust the impedance that's basically like a slider on an graphic equalizer with a very wide band.

You can probably just tweak it so that it sounds "good".

To be more precise you would need a calibration record and adjust the impedance setting until you get a more-or-less flat frequency response sweep but that requires more equipment and time and effort that you're likely to want to do. 

Keep in mind that your phono preamp stage also applies RIAA equalization.
Dear friends. If what atmasphere posted: """  the cantilever to do more work and makes it stiffer, less able to track higher frequencies.  """

if that theory is a proved reality then it's welcomed because what a cartridge designer is looking ( between other characteristics. ) is that for cantilevers build materials on choice  its Young Modulus value be the higher  one and that's why the first/main choices are diamond and Boron over any other cantilever build materials that have the higher YM values.


""" Young's Modulus alt. Modulus of Elasticity - is a measure of stiffness of an elastic material. It is used to describe the elastic properties of objects like wires, rods or ...... """

So it's not wrong as he always says but at the end I never seen a white paper that proved that theory and again if already proved then welcomed !.

R.