Need help with phono cartridge selection

How old are these carts? I haven't heard of either one. Are they similar in age to your Hafler and Snell (25+ years old)? If so, the rubber suspension has probably deteriorated. I'd have them checked out before using.

They are late 80's models...but I purchased them recently new in the box. I examined the stylus, cantilever and housing and they are spotless.

There is some blog info out there about the 10A...but precious little on the 20C. The 10A retailed for about $ 390.00 and the 20C was around $ 550.00. They both have very dynamic sound reproduction qualities and I have the orginal spec sheets and independent test metrics. I am just not that knowledgeable about high versus low outputs and their interactions with the equipment I own. The Preamplfier has a MM/MC switch in the rear that is tied to a phono stage in the chassis so I am able to utilize the MC cartridge...but I don't have the paperwork any longer for the Pre so I can compare specs for it against the cartridge.

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