SUT Hum

Good to know that there is nothing wrong with the SUT.
Thanks.

Yes - this suggests that in your SUT the chassis is not grounded unless you connect a wire to the preamp from the earth post of the SUT. If the SUT chassis is not grounded then all the soldered connections inside are unshielded and prone to RF and this is why the noise reduces further when you connect the SUT ground to the preamp.

I connected the ground cable from the turntable to SUT and a wire from the SUT to the phono preamp.
Then, most of the hums were gone. The level of hum was further reduced compared to the ground cable connected to the phono preamp or the preamp.

Is it normal?

Yes- that is normal.

Don't get this thread. Ground connected to preamp, NO hum. No problem.
I'm just say'n ✌️

Thanks for all response.
I connected the ground cable from the turntable to SUT and a wire from the SUT to the phono preamp.
Then, most of the hums were gone. The level of hum was further reduced compared to the ground cable connected to the phono preamp or the preamp.

Is it normal?
Previously I had a cinemag SUT and I only connected the ground cable from the turntable to the SUT, and the hum level was very low.

What happens when you tie the ground of the SUT to the preamp While the phono ground is also at the same point? Still get the hum?

The point is to have a hum free SUT. Whether that is accomplished with or without a ground wire, or where that ground wire gets placed, doesn't matter.

Have you tried connecting the ground cable from the table to the SUT, and then from the SUT to the preamp?

No. I don't think so. I think you just create a ground loop. My tables and preamps work the same way: some on, some off.