Cartridge Loading- Low output M/C

Wyn, I am glad that JCarr finally mentioned the fact that most LOMCs I know about have a much lower nominal inductance than the 0.5mH, on which you based your first set of calculations, and thank you for re-calculating your results based on more realistic values of inductance.  I also want to thank you, Al, JCarr, Ralph, and others for this civil and erudite discussion.  Such educational interchanges are all too rare on audiophile websites.  I only recently experimented with reducing the load on my LOMC cartridges, which is to say I am running them at 47K ohms routinely now.  I find the sonics to be more open and airy that way, and I feel no impulse to move back to the more typical 100R value.  I am sure my results have most to do with the nature of my particular phono stage, my downstream components, and my two ears,

In my experience, a very low resistive load, which puts a correspondingly heavy load on the cartridge, acts like a tone control, which is to say that as you approach the internal resistance of the cartridge itself, the treble is rolled off progressively and eventually some gain is lost to ground.  In theory, if the internal R of the Cadenza is 5 ohms, the minimum load resistance would be around 47 ohms, or 10X that of the cartridge, as someone else already suggested above. But I have lately found that even LOMC cartridges sound their best when the cartridge is essentially un-loaded, at 47K ohms.  The treble is more "open" and airy.  Dynamics are also improved vs more traditional values of load resistance.  (LOMCs with low internal resistance, like the Cadenza, are traditionally loaded with 100 ohms, a set it and forget it value.)  Ralph Karsten (Atma-sphere) points out that not all phono stages behave properly when LOMCs are presented with a 47K load, so maybe I am just lucky.  I agree with the person who said that the "best" choice is phono stage AND cartridge dependent.

Al, Thanks for bringing up the question of metering. I do own a Sencore LC meter that can measure down to the pF level. If I want to measure the capacitance of a cable, do I just place the Sencore probes on the hot and ground of the cable, with the other ends (hot and ground) unterminated? That seems right, but I am not sure.

I also think this might be a good place to summarize the points made by Ralph, Al, Wyn, etc.  First, no one is saying that there is only one correct load for a typical LOMC cartridge with very low internal resistance.  Second, I think Wyn has conceded that his first model for the behavior of such a cartridge when driving a phono stage was based on some usually false assumptions: (1) that such cartridges have coil inductance as high as 0.5mH, and (2) active RIAA correction in the phono circuit, which is atypical of most of the “best” phono stages capable of working well with such cartridges without a SUT.  Assuming inductance in the low micro Henry range and passive RIAA, we should keep associated capacitance as low as possible.  Under all these conditions, it is not inconceivable that a high resistive load, e.g., 47K ohms, might sound better than the more typical values of load resistance used by us audiophiles, e.g., 100R.  In my case, I can say that the difference between 100R load an 47K is not huge by any means, but once I had tried 47K for at least 2 or 3 of my LOMC cartridges, I’ve developed a preference for it.  What I hear is as predicted, highs seem more open and extended.