Cartridge

I assume you want entry level price as you didnt mention the all important budget for your purchase, I have the Clear Audio Beta and I own a Dyna 20x, tho I dont know the 10X....in general the Dyna from what I know is a more musical cart, make sure it is high output.

The Grado Gold is not a bad little cartridge.
Typically it can be found for $150 or so new.
My brother and my brother-in-law both use it.
(Not the last word in resolution or the darkest of backgrounds, but it is pretty good, and a good bang for the buck cartridge.)

My two cents worth anyway.

A couple of comments. . .when I first got back into vinyl I used a pretty cheap ($75) Grado that didn't look like much but was enticing enough to keep me interested. I currently have the Clearaudio Virtuoso Wood which is a more expensive relative of the Beta and I'm completely pleased. The Beta was very well reviewed and I think is still considered to be a winner at it's own price level, as well as at even higher ranges.

Regarding the phono stage, your son may need one regardless. While MC cartridges generally are lower in output than MM cartridges, even MMs are not putting out line level voltages like that of CD and Tape.

Generally speaking, phono stages are far less common as 'built in' features than they were back in the day before CD. His pre-amp or receiver MAY have a phono input and if so, it's likely to have enough gain for an MM cart, but possibly not enough for an MC cart. In the event his rig does accommodate phono input, it might be useful to find out how much gain it has--this is usually expressed in dB. Hope this helps!

To answer some of the questions posed:

1. Yes I am looking for a budget cartridge. Less than 500.
2. He has a amp with phono stage that is MM 2.5mv. So most high output MC carts should work.

Thanks again for your advice. It is very helpful!

Thanks!!

One more thing I am also slighty interested (may be more money than I want to spend) in the Dynavector 20xH. Let me know the your compairsons between the 20xH and 10xH. Thanks again!