Turntable, where is my bass???

Hi, I've noticed a clearly diminished low frequency output with my analog gear lately but cannot put it in precise timely relation with a particular event since I have mainly been playing newly acquired records during the last few weeks or very old ones that I hadn't heard for years. But now, the familiar records surprised me with a lack of "something" (there was actually one recent change of IC)

The chain of the signal is Transfiguration Spirit III cart -> Well Tempered Reference arm with original wiring sitting on Well Tempered Reference table -> Synergistic Research Tricon analog IC -> Tidal Preos pre-amp.

Possible culprits I can think of:
1 (the one I hope it to be) The SR Tricon is only a few weeks old; before that the dealer had lent me a broken-in demo cable that I was allowed to keep several weeks until my newly ordered one arrived. So could this be a questin of break-in?
2 Could the arm somehow have "deregulated" itself, e.g. in respect of VTA?
3 Resistive load is fixed at 120 Ohm; could I just be growing aware that is the wrong value? Does anyone know the preferred value for the Spirit III ? (I can't experiment changing it myself, but the Tidal guys could fix another value if can tell them which one)

Does someone know of other possible causes that are perhaps subtle first and then just "snap"? It can't be my hearing since I don't notice any change in the digital department.

Thanks for your insight.
Karel