Cartridge impedance loading question

I owned that excellent cartridge and loaded it at 100 Ohms.

The correct loading for the cartridge is 47K ?

There is no "correct" loading. Assuming you're going straight in, why don't you start at 100 ohms as suggested by Shelter and adjust it to taste?
http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1077125197&openfrom&1&4#1

I've used this cartridge for a number of years.
My various phono stages have all been of the moving magnet kind, 47Kohms at input. I have adjusted loading by means of different step up transformers.

For a long time I used an sut that reflected a load of 470 ohms back to the shelter, while stepping up its output voltage by 10 times. (aka 1:10 turns ratio)

And I enjoyed the cartridge quite a lot at this loading.

I have also loaded this cartridge at 209 ohms by using a sut with a turns ratio of 1:15.

With regard to your options with the Black Cube I'd try it at both 100 ohms and then 470 ohms. Choose between those.

I haven't tried it, but it has been suggested to me by someone who has that a 1000 ohm setting works very good with the 501-II. For me that would require an SUT with a 1:5 turns ratio.

My phono stages that I have used with the Shelter have been tubed, except for a couple that I tried for brief periods and returned. I haven't tried the Black Cube.
Current stage is a Hagerman Trumpet which I find quite ageeable with the rest of my signal chain.

And, of course, your mileage might (and probably will) vary.

-Steve

-Steve

There is no "correct" loading. Assuming you're going straight in, why don't you start at 100 ohms as suggested by Shelter and adjust it to taste?

I take it from this an other comments that my post was not read through completely! So, to reiterate in other words:

The correct loading for any cartridge will be such that it does not ring at audio frequencies- IOW if you run a squarewave through it, a squarewave will come out with no ringing.

With any LOMC cartridge ever made, this will be the case at 47K. So why do we hear differences? It has not so much to do with the cartridge and **everything** to do with the phono preamp. If the preamp is sensitive to Radio Frequency Interference, then loading the cartridge will affect tonality as it detunes the RF circuit formed thus:

The RFI (Radio Frequency Interference) is caused by the excitation of the RF circuit formed by the cartridge inductance and the capacitance of the interconnect cable. The loading detunes the circuit so the RF bursts cannot occur.

-as I mentioned earlier. IOW, if loading is audible in your system, your phono section is sensitive to RFI.

Please note that the correct loading value for such a preamp cannot be predetermined since the cable is part of the RF circuit and its capacitance will affect the value. If the manufacturer of the cartridge recommends a particular value, it simply means that *their* reference preamp has troubles with RF and nothing more. But you will find that most manufacturers recommend 47K as it is correct.

* The correct loading for any cartridge will be such that it does not ring at audio frequencies- IOW if you run a squarewave through it, a squarewave will come out with no ringing.*

Ringing at audio frequencies might be a your criteria for loading an MP-1, but there are certainly other considerations for the rest of us, and I would think for MP-1 users as well. That is the sound, irrespective of RFI.

That bit about squarewaves is cute, but would leave a lot of people scratching their chin and changing load. I'm not saying your criteria is irrelevant, but it's not the ONLY criteria.

* With any LOMC cartridge ever made, this will be the case at 47K. So why do we hear differences? It has not so much to do with the cartridge and **everything** to do with the phono preamp. If the preamp is sensitive to Radio Frequency Interference, then loading the cartridge will affect tonality as it detunes the RF circuit formed thus*

Changing load does not necessarily affect tonality. The highest value or 47K is often not the most desirable. BTW, why stop at 47K, why not 1M or infinite?