Simaudio MOON 610LP with Lyra Kleos

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

Can't think of too much. I'm assuming you are using the single ended inputs and outputs on the 610 and that the balanced jumpers are inserted?

Apart from that I would be setting the gain initially at least at the 56 dB setting as the Kleos appears to have a relatively high output of around .5 mV.

It also has relatively low internal impedance around 5.5 ohms so I would initially experiment with the loading in the 75-150 range. But Lyra has a very wide range spec'd for loading (supposedly based on the capacitance of your phono cable) so you may end up experimenting with much higher ranges than that.

What what do you think about using a step-up transformer? Bobs Devices have couple of models all with a ground post and use the Moon in MM mode?

So..a new issue? Can you be more specific as to when you first noticed this issue?

It is a new issue. But each one of these components have been used in other combinations, including cables.