Need help with phono cartridge selection


I have 2 Dynavector phono cartridges. Ultimo 20C and Ultimo 10A. I know that the 20C is a low output MC and that the 10A is a high output cartridge. I have sampled half speed mastered vinyl with both mounted on a Denon DP 30L II turntable and have experienced pluses and minuses with each cartridge. I am using a Hafler DH500 amplifier with a PS Audio 5.6 Preamplifier for electronics and Snell Type A loudspeakers. Simple question...with this setup... which cartridge should I keep ? Ultimately my ears must be the judge and I understand that, just looking for opinions.
rettuc01
Retuc01 - charts and graphs mean very little. The cartridge sound is the important consideration. If you like it fine, however, the fact that it is so old is suspicious. Rubber parts deteriorate from ozone in the atmosphere...things harden and soften.... I would have it checked out by Dynavektor..it probably needs a rebuild.
You say you have heard plus and minus'with both cartridges. Neither will have value in the re-sale market.
Therefore the simple solution is KEEP BOTH OF THEM
Good answer. :)

They both exhibit wonderful sound reproduction.

My post was mainly for obtaining information from folks that have had system experience with the aforementioned products, so I can benefit from that knowledge and properly evaluate the cartridges.
If part of your question is how to get proper loading/matching for these cartridges:
1.) The low output should be run with the pre-amp set to the MC position for the phono input.
2.) Most high output MC carts were designed to mimic standard MM carts in terms of output level and load requirements - so try that one with the pre-amps phono input set to MM.
Assuming that your high output MC is actually high output (MM signal levels) - you don't want to run it into a MC input because you'll probably electrically overload the phono input - this will sound really awful. Years ago i had a customer repeatedly bring in his table/arm/cart complaining about mistracking - which we could never reproduce on the service bench setup. Finally visited his home and noticed he was running into a MC input with a high output MC - he thought he was getting more power because he didn't have to turn his V/C up as much in the MC input - but on louder passages the distortion was truly awful because of overloading the input.Switched to MM input and all was well.