grk, that opinion article you mentioned above (very well written by the way), does not apply at all to the possible differences between the impedances of the phono EQ-500 and the Hana Umami cartridge.
(https://www.mysonic.space/phono-cartridge-impedance-loading)
These differences (as I was almost sure) are entirely irrelevant and do not apply to the one mentioned by the opinion article author.
I had already informed myself from knowledgeable people in the field that there would be no problem at all, which was confirmed by Luxman themselves.
Here you can see the answer that luxman sent me:
"The HANA-Umami quoted output of 0.4mV will be accommodated by the Luxman EQ-500 “low” MC input (0.18mV minimum sensitivity) required to drive EQ-500 to full output while preserving S/N ratio.
HANA-Umami’s quoted internal impedance of 6 Ohms would be best partnered via the EQ-500’s “low” input impedance. (i.e. 2.5 Ohms)
In this case, the 6 Ohm matching of HANA-Umami coil output impedance to “low” EQ-500 input impedance is within acceptable operational parameters.
While the HANA-Umami’s published specs calls for “recommended loading” of > 60 Ohms, this would not always apply. The 60+ Ohm recommendation would likely refer to “semiconductor/ fixed resistor based phono loading”. Along with its unique vacuum tube based circuitry, the EQ-500 features independent L+R channel “transformer based loading”, having unique electrical behaviors. The Luxman EQ-500 (internal) transformers can present ideal loading when they are at OR near the MC cartridge’s actual internal coil(s) impedance. In this case, 2.5 Ohms and 6 Ohms are very close and compatible.
The employed tonearm cabling and connectors will also provide slight/ additional series Ohms loading. (before signals reach the EQ-500 input, making the Ohms match even closer.) The various other front panel settings (Capacity, Impedance, etc.) on the EQ-500 are for use with Moving Magnet, Moving Iron, or Induced Magnet phono cartridge types. These do not factor into Moving Coil cartridge performance.
While many things can be written on the Internet, what is provided to you here are direct comments/answers from the Luxman engineering staff in Japan."
Thanks any way.