Cartridge incompatibility, Soundsmith and Luxman

Larry, If you read the responses, you will know that the problem is almost certainly the fact that the fixed value of the load resistance at the phono inputs of the Luxman is 100 ohms.  The Zephyr is a rare low output MI type, which has high inductance compared to a typical LOMC type.  Thus it needs a higher value load resistor.  The high inductance cartridge into a 100 ohm load would be expected to exhibit all the characteristics that the OP is not happy with, and justifiably so. That issue would have to be dealt with before one could fairly evaluate other elements in this system.

First, I'm not going to open up the amp and modify it. By the time I do that, I might just as well spend the money to get a different cartridge. Yes, I do like the Zephyr, but there are other good ones out there.

Larry, yes, I do love the sound of the 590axii. It's ONLY the phono that sounds extremely dark. Switching to a different cartridge (I have a spare MM cartridge) opens up the highs to be just like my streamer (or CD for that matter). It's a compatibility issue between the fixed load and the cartridge.

I have read the responses, and in fact, I suggested a cartridge with a source impedance below 10 ohms, in acknowledgment that that might be a way to avoid the incompatibility problem.  I just wanted to be sure that the OP did not get off on the wrong track.

I hesitate to offer specific recommendations because cartridge preference and system matching is so personal.  If I were to hazard a guess, a Lyra cartridge might be a good match--most have quite extended highs, a very clear sound, and have a fairly low source impedance that would be compatible with the 100 ohm loading of the phono stage.  I own an old Lyra Titan and I like its sound, although these days I run a Transfiguration Orpheus L.  

Larry, The low output Zephyr already has a low internal DCR of 10 ohms.  That's not the problem.  The problem is its inductance, which, at 2.5mH, is about mid way between a typical LOMC (about 50 microhenries) and a typical MM (500 millihenries, or about 10,000X more than the LOMC).  If the Luxman was mine, it would have been "modified" last week. I don't really view this as a modification in the usual sense that we use it, because the change does not alter the circuit or alter ("upgrade") the parts content.  I'm envious of your Orpheus, BTW.

audiojan, I realize the die is cast, but to say you "might as well spend the money to get a different cartridge" indicates money is not an object. Because changing the resistor, even if you must hire someone else with the expertise to do it, is bound to be the less expensive alternative.  Anyway, your problem is solved one way or the other. 

Yes, I agree completely.  I made the recommendation for low impedance cartridge because I thought the OP is set on finding a MC replacement for the Zephyr and I was trying to suggest staying with low impedance cartridges to avoid the same sort of loading issues.