VPI ARIES and Lyra Helikon SL

What phono stage are you using? This could considerably effect the sound.

You didn't describe whether/how you set overhang and azimuth (a point that Albert raised above), but if that is not done correctly, you won't get the best performance from the arm/cartridge.

If you need some tools to help with setup (again, I don't know what you have), you might take a look at those available from a small company called Turntable Basics. They sell a very easy-to-use device to set overhang, etc., and a bubble level. Here's the Web site:
http://www.turntablebasics.com/

I also assume you have a tracking force gauge. If not, one of the cheapest and easiest to use is the Shure SFG-2, which you can buy from several audio shops for $20.

Is there distortion at all frequencies or only at the high end? If its only on top, I'd be patient and see if it becomes less as the cartridge is broken in. If its through the entire frequency spectrum, I'd follow all the steps very carefully as Albert has suggested and also read the advice page on the turntablebasics site, which Sdcampbell has pointed out. Cheers,

I found this to be helpful in setting up my mono Helikon:

http://www.audioasylum.com/audio/vinyl/messages/54417.html