Strange subsonic rumble problem?

I am not sure what do you mean by grounding problem? I assume it is the ground lead from phono cable or is there something else? The FR has no problem when connecting through Thoeress preamp though so if it is a problem in the arm itself, I assume that the problem would occur with either phono.
In my Aesthetix Io Eclipse, I only have tubes in first 2 gain stages and not in the third so it gives about 50 dB of gain plus Audio Tekne SUT which gives just the right amount of gain for Ikeda. This combination works great with Ikeda on my
FR 64s for many months. I tried replacing Audio Tekne with Ikeda SUT and the problem is still there.

Will have to find tubes to put in the third stage and bypass SUT completely and see what happen.

Bad tubes are probably less likely as well as rumble occurs in both channels. Chance of tubes failing in the same way in both channels at the same time probably is pretty low.

I talked to my Aesthetix dealer and they will get back to me.

Suteetat

Well you have ruled out the Tekne SUT with the Aesthetix since it works with your other arm.

Perhaps the ground lead has come undone inside the arm. Check continuity with a meter.

Hmmm.. I think it is definitely the phono unit that is causing the problem. Ground on FR66s seems to be fine.
Today, I tried Reed/Lyra with Aesthetix and rumble occurs again (neither FR or Reed had rumble with Thoeress phono).
I put Kinetic Wave footers under Aesthetix and that seemed to reduce rumble a bit as woofers are not pumping as much but rumbles are still there (may be I am only imagining this). My Aesthetix dealer (also distributer) unfortunately left for CES a day after I talked to him so will have to wait until he comes back in a couple of weeks... oh well.