@handymann A year ago or so, I had the same problem as you, especially with LOMC cartridges. The solution was isolating the turntable. In my case, I used Anvil turntables excellent magnetic footers, but I'm sure there are other good solutions. These isolating footers works despite the fact that my table was in the front corner next to the speaker with a powered sub. Ultimately, further improvements to the sound of my system occurred when I moved the turntable out of the front corner to the rear of the room using a long XLR connection between amp and preamp.
FWIW, I tried the tap test on my Koetsu/FR-64S combo this am, with the pre at playback volume. I heard nothing through the speakers. Admittedly, I didn't have someone's ear right in front of the speaker.
FWIW, I tried the tap test on my Koetsu/FR-64S combo this am, with the pre at playback volume. I heard nothing through the speakers. Admittedly, I didn't have someone's ear right in front of the speaker.