@audphile1
I’m curious to know what particular frequencies excite the phono stage chassis and PCB to impact the sound quality. I have no way to measure it though
I am just the poor interpreter / reporter here!
SoulNote would probably say you are using your frequency brain. Tapping is time dependent, not frequency dependent.
They would also say don't measure first, first use your ears. Almost all easy measurements are in the frequency domain, but they say these, when optimised for frequency, are often detrimental to the real sound quality which is always in the time domain.
100% with you on turntable / cartridge resonances. I often tap mine to see if my sorbothane hemispheres are calculated correctly, and / or are settling under 60-kgs load. There's probably some mythical burn-in time for them, and they need to keep away from the Holbo's resonances!
Massive panels store energy for longer. Lightweight panels dissipate it earlier (time domain brain).
I also find it interesting that SoulNote likes lightweight interconnects. Obviously they are less likely to transmit resonances than stiff, heavy interconnects.
After all, our entire universe and everything in it resonates