Cartridge incompatibility, Soundsmith and Luxman

@billwojo where do you get $1000 from?! By the time I sell the cartridge I have and get a different one, it’s pretty much a wash.

I think am guessing that the $1,000 comes from the amount you are willing to spend on a SUT, such that paying for a modification would have to be at or above that amount to be out of the running as an alternative.  Most repair places will charge for the modification by the hour, with one hour at a minimum.  I would expect that one hour’s labor would be charged, and the lowest charge I would guess is $120 per hour.  I would guess $160 per hour is more realistic, so expect $180 as the total cost. For future versatility, you should consider a very high value resistor (meaning LOW loading), with the use of loading plugs to set the particular value for your cartridge; that might mean paying the technician make loading plugs. The ideal approach would be having cheap plugs of various values (e.g. 80, 160, 320, 1,000), and after ascertaining the correct value, I would hard wire a quality resistor between the positive and ground of the back of the input jack (easy to do and safer than desoldering the resistor on a circuit board which may accidentally damage a trace).

The SUT approach would require not only the SUT, but also a decent interconnect (shielded interconnect to minimize noise pickup).  This is an expensive approach and you run some risk of noise problems that are hard to resolve by finding the right location of the SUT, but, I personally like the sound of them.

If the OP wants to sell his Zephyr cartridge, I am interested. Just saying. I don’t advise it, but I’m interested.

Let me repeat the option of buying a $289 Hagerman Piccolo2 as a "stopgap" for use with the Luxman MM stage - it will properly load the SoundSmith, and it will allow OP to discern if he likes the cartridge enough (I mean REALLY likes it) to keep pursuing its options. It can be sold to recoup funds at the end of experiment. Or it might sound good enough to keep in place for a while.

I used one on my Benz LPS and it handily beat SUTs which couldn’t optimally load that cartridge into my VAC Renaissance SE phono stage. No, on even ground its circuitry isn't gonna match the refinement of OP's Luxman or my VAC, but it will beat the crap out of any loading mismatch!

Mine arrived in a week from Hawaii. Like British Mullard tubes, it might not be what you settle on, but it’s a handy addition to your audiophile toolkit.

@audiojan , the finest 1% metal film 47K resistor costs maybe 75 cents. If you lived anywhere near me I would be happy to do it for you. I live in NH. Cost you a bottle of scotch. Lagavulin please.