VPI ARIES and Lyra Helikon SL

First thing, check the overhang and mount hole alignment. If that is perfect, be sure you have the proper resistance load for the Helikon. I have not experimented, but bet it is well below 47K, probably near 22K.

Next, lower the VTA to a few degrees below level at the rear of the Graham arm. This may be as much as one fourth of an inch, must be determined by ear. This should clean up the highs and improve bass. You turntable must be absolutely level, the Graham hates being out of level.

Set tracking at heaviest setting suggested by Helikon, check cartridge centering and parallel alignment within the Graham head shell, and be sure the suspension system is free of any encumbrances. The azimuth is critical as well, set a red sable artists brush gently against the side weights of the Graham to hear changes while listening. This is dangerous if you lack the delicate touch, obviously do not try it if you have concerns.

Let us know how the experiment goes.

On break in, probably minimum of 100 hours.

The sound of unbroken-in cartridge should not be distorted.
It shouldn't be distorted neither from VTA nor from load. The common error can occur when misplacing green with blue wire.
Otherwise you should contact Immedia and if necessary follow the exchange procedure.

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.

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

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

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,