Simaudio MOON 610LP with Lyra Kleos

It’s more humming than hissing. And while we are st it, what’s the difference in the source and why it won’t go away?

60Hz hum is usually improper grounding or due to a ground loop. Not easy to solve. Make sure that the cartridge leads are snug. Tonearm has ground continuity all the way to the ground post. You may even try disconnecting the ground cable entirely as a test. 

There may be another component in the system that is causing a ground loop. Cable box is a very common culprit. Light dimmers. And just about everything else.

Hissing is input noise from the OP amplifier. In your case I believe it's a National part, LM4562. It's very low noise, but some hiss will be audible if the preamplifier's volume is turned up and no record is playing. There are quieter designs using discrete jfet inputs. 

When did this problem become evident? How long have you had these components? Is the SIM’s MC gain, compatible with the LYRA?

I can assume that if your using a Kleos, in order to maximize that investment, you'd need another phonostage.

It's a highly configurable $7500 phono stage so it should be capable of  working with the Kleos.

But how long the OP has had these, especially the phono stage, is a valid question as we can the deal with some possible setup issues.

Is this your first time using and setting up the Sim Alex?

Good mornig, WOW, a lot of replies came overnight :)
Thank you all for your suggestions! 
Just to clarify couple of things: I use Clearaudio Performance DC table with Satisfy Karbon arm (has tonearm cables hard-wired, including the ground wire). Table, arm and Kleos have been used before in a different setup and were quiet. I've also used 610LP in another setup for a few months and it was completely quiet - no hiss, no humm. 610LP is very flexible and is definately compatible with Lyra.
There are no cable boxes, light dimmers, etc anywhere near the setup. 
There is a passive speakers switch box, Luxman AS-55 but once again, it was used in a different setup before with no humming effect.
Speakers are set 12 feet away from the table. 
I've tried to use different cables, different inputs on my integrated amp, connecting and discommecting ground wires from the bearings and/or the arm, turning off (disconnecting mains) all other components in the system except table, phono preamp and integrated - all with no success.
Anything else I should try? But please, anything short of replacing 610LP or the cartridge :) 

Thanks again!
Alex