Simaudio MOON 610LP with Lyra Kleos

With a step up transformer, you will take a significant hit in sound quality.

I suggest that you check Bob's devices web site for his article on grounding problems and how to solve them. It is the best piece I have seen on the subject. You probably don't need a step up transformer with a .5mv cartridge but I can tell you from experience with many cartridges that a good step up transformer helps
the sound stage significantly on low input MC cartridges. 

Finally, I would bet that you have a ground loop hum somewhere in the system. Make certain that all of your phono cables are far away form electrical components with transformers. 

Thank you 

Dear @alexkrich: Your 610 is a very good unit and it performs better if you use it balanced because is the way was designed ( fully diferential. ). I agree with @hdm that you need nothing with, obviously not a SUT that only can degrades the quality level performance in the cartridge signal due the great 610 design and excecution design.

First than all balanced way is the way to use the 610, nothing on it can compares connected in non-balanced way.


""" I have the arm and bearings grounded ... """

what do you mean with that?. Which bearings are you talking about? because if tonearm is grounded then that’s all you need ( tonearm bearings are part of the tonearm. ) and additional you have to have grounded the TT.

I never had any issues with my Kleos and other Lyra cartridges as the one you have.

As @browndt said take care that the IC tonearm cable always stays away from electrical lines or transformers and if the IC has to stays near electrical lines/power amp cables then the IC tonearm cables must cross over those lectrical lines at 90°.

Could be too that somewhere the ground wire was disconnected/unsoldered, so you have to check to be sure all the ground wires are soldered to its terminals.

I repeat, with your 610 avoid to use any SUT.

regards and enjoy the MUSIC NOT DISTORTIONS,
R.