Cartridge incompatibility, Soundsmith and Luxman

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.  
 

That's for sure. If he wants to let the tail (the 100 ohm resistors) wag the dog, then he must acquire a LOMC with typical LOMC inductance.  But also gain must be high enough to work well with the inherent gain of the MC section (plus the linestage gain) of that Luxman. (I don't know what that is in db but evidently it was not a problem with the 0.3mV output of the Zephyr.)