MONO cartridges

I recently purchased a Lyra Helikon mono to play the many mono records in my lp collection. First record after break in
was excellent condition original Blue Note records "Art Blakley and the Jazz Messengers Vol. 2". Stunning presentation and detail even compared to my Airtight PC-l stereo cartridge. Several other Blue Notes produced similar results.
My phono pre is a balanced Einstein "The Turntables Choice".
I tried a Shelter 501 Mk 2 mono which has a single coil, but it's single coil design caused a low volume ground hum which is sometimes the result of using a modern phono pre with a single coil mono cartridge. Since the hum was pretty low, I was still able to ascertain that the Lyra presentation was clearer,larger,and more detailed and alive than the Shelter. Of course it's double the price too.
Got the same hum with my Einstein single ended phono pre
and my AHT Non-Signature phono pre [same design as the Walker phono pre without all the added tweaks,etc]
Be careful if you opt for a single coil pickup at the lower price point that it does not hum with your phono pre.

I have a question as to the best loading for the Helikon.
It's specs say 100ohms to 47k ohms. My Einstein has loading resisters of 40,85,100,150,300, and 940 ohms.
Is this cartridge load sensitive in anyone's experience?
What loading are the other owners using and the results?
None of the reviews of this cartridge comment on loading differences. The instructions talk about the potential difference, but I cannot clearly hear one in a quick initial comparison, but I didin't try very hard. Just wanted to sit and listen to the beautiful music I was finally hearing from those records. Waited a long time for this moment, so testing will have to wait. Thanks for any input.
I have mounted it on a Dynavector 507 Mk 2 arm on my TW Accoustic Raven one TT.

Thanks for your response Hevac.
I will try mine at 940 ohms which is the highest loading I have for the pre without ordering new resistor plugs.
Did you try yours at a higher loading before making final load decision? They state the higher the loading, the more open the result.

Syntax,
I am posting a reply that I made to another recent thread on the Shelter 501 mono cartridge.

06-10-09: Sabertouch
Davt,
I owned the Shelter II mono for a couple of months. It exhibited a low hum with the 3 high quality phono stages I own. Finally discovered it was a single coil design [not in specifications or description anywhere]. Install instructions were meager. It sounded pretty good even with the hum which was only there during quiet passages. Tried everything to get rid of the hum. Learned of another owner with the same hum problem.
Bottom line. Most of todays phono pre's have grounding designs which will cause hum with single coil mono pickups.
I bought a Lyra Helikon mono which has a two coil design and great instructions. It easily bettered the Shelter in detail, soundstage, realism, tick and pop resistance and dynamics. Quality is excellent.
The Shelter is good too and I would probably would have been happy with it if I could have found a way to eliminate the hum. In my research into the problem, I found not much is known about mono playback component compatibility in the vinly community since very few are sold.
Incidently, I was floored by how much better my mono lp's sounded with the helikon as compared to my very expensive and highly regarded stereo cartridges. To hear a Blue Note original from 1959 with a Helikon mono is an amazing sonic experience.
I don't know if the other expensive stereo cartridges which have been converted to mono output are better than the Lyra. They were originally designed for stereo output and not mono and have been converted to mono through internal wiring changes.
It is easy to find forum input on the Helikon if you dig a little. It appears quite a number have been sold. You can also find some good magazine reviews.