Cartridge impedance loading question

A LOMC cartridge without a core is going to have a lower inductance value as compared to one that does have a core. A core has a way of increasing the inductance, all other variables being equal.

As Jcarr points out in one of the links I provided, and IME, as you load the cartridge more and more the output goes down, which makes for more noise from the phono section. Generally speaking, the greater amount of noise the less low level detail due to the ear's masking principle.

In our preamps you really don't hear any difference with 500 ohms or 47K; our preamps are pretty immune to RFI. I've not been contesting that you don't hear an improvement- in fact I am quite sure you do. All I am saying (and all I have ever said in this thread) is that if so this indicates that your preamp has a problem with RFI. So in your case loading is important. But what works for you is not going to be the same for someone else with the same cartridge if they have a different preamp and tone arm cable. That was brought out in the links I provided.

I load everything at 47k these days as I now use an Atma-Sphere MP-3. I have tried different loading for my MC cartridges but hear no difference. I remember talking to Keith Herron several years ago at a RMAF show. I asked why his phonostgae did not have loading options. He pretty much gave the same answer as Ralph. Ironically though the next version of his phonostage did come with load options, but While he never admitted as much to me I think he did that for marketing reasons.

Atmasphere,
A coil with a magnetic core is more efficient so air core coils must be larger to get a usable output. The newer AT air core designs are the exception, probably using stronger magnets. Older designs like the DL-S1 have very low output and relatively high impedance/inductance.

OP has a Black Box, not a Herron or MP-1, and I would guess that some of what you say about to the higher usable value, might be appropriate, but it's not a rule.
One of my solid state phonos' has a much higher S/N, and it's obvious your loading "rules" are not always correct.
Regards,

The larger you make an air coil, the lower its inductance.
https://en.wikipedia.org/wiki/Inductor

The noise that a phono section has is usually not a function of loading. There are a lot of factors that have to do with noise- it is an immense topic.

The 'rules' are simply the laws of physics- and are impossible to violate.

All I was saying is that if you load a cartridge (like any other source), the result *can be* reduced output which will mean that the noise floor is higher.

Apropos of Atma's last two posts, last night I auditioned for the first time a newly acquired Ortofon MC2000 cartridge, one of the lowest of the "LO" MCs ever made. The MC2000 is said to have an internal resistance of 3 ohms, so a 100R load would seem to be quite appropriate. However, I inadvertently loaded it at 47K, as I began my listening session. This is using the phono section of Atma-sphere's own MP1 full function preamplifier. My MP1 has more than ample gain to accept the output of the MC2000 directly. In any case, I was blown away by my initial results. The MC2000 is one great cartridge, certainly one of the best sounding LOMCs I ever have heard in my system. After about 30 minutes of bliss, I noticed that I was running it at 47K, instead of 100R, which would have been my first choice. So I switched it over to 100R. With that load, it's still very good, but I think the sound lost some magic. The bass response was a little sloppy at 47K compared to 100R, but every other facet of reproduction was at least a little if not a lot superior at 47K. Pending further evaluation, I am a convert to 47K for LOMC, or certainly for the MC2000. I may try 1000R just to see if that tames the bass a bit, compared to 47K.