Cartridge and stylus being equal, the 30 year old Pioneer PL115D actually sound better than the more expensive and elaborate JVC QL y66F and I wonder why?

I have tested a Shure N75ED/2, a M70EJ, and the SC35C carts all using the same aftermarket stylus- the SC35 C is a DJ cart but I am not using the DJ stylus.

In every instance, the PL115D sounds, well, stronger and more robust, especially with the SC35C cart...The JVC seems to be subdued in comparison.

Why?

Is there a tonearm/cartridge/stylus compliance issue that I am screwing up?
The JVC was originally equipped with the JVC moving coil cartridge/stylus.

I would expect more performance from the JVC, not less...I set it up following the owner's manual instructions. And I set up the PL115 following its manual as well...any suggestions?

The pioneer turntables especially the older ones sound awesome. I have a PL-41 and its amazing. The newer JVC's are good but only with the newer cartridges like the ADC integra XLM's. Plus the shure are older school cartridges and the pioneer is an old school table. So they are a better match. Just my opinion though. You will get varied responses here some of which are table experts.

Probably the condition and parasitic capacitance in the cabling between the TT and the phono section. Try both with new headshell leads and a pair of new cables, then make your choice.

You are referring to the input cables from the turntable to the phono jacks on the receiver? This must be what you mean. I recall the leads from the tonearm make a direct connection to the output cable. There is no amplifier section...headshellleads. Not a bad job. But you know I would think the older pioneer would be the one to have that problem...age, deterioration etc...