Dynavector DV20x2H cart for MM phono stage ?

Provided the gain is at least 40 dB or so you should be OK.

My friend uses it with the built in MM phono pre of a Rega Brio R and it sounds great.

I had the 20XH and 20XL and I tried them both with the whest 2.0 phono stage. It offers MM and MC at I believe 70DB gain. With either the L or H version I preferred the MC input. It has always sounded weak and light with the MM input. So I don't know if it's my phono stage that is the culprit or the 20XH would like to see more than 40DB gain I can't say but in any cart situation I've been in I like more gain than less. I really don't like putting my volume knob at 3pm on the dial if possible

"Can I use a preamp with MM phono stage for this cart?"

Unless you have an exception like Ejlif and his Whest, you will need to use a MM phono stage. Otherwise, you will almost certainly get a lot of distortion. Being able to use a MM phono pre, in your situation, is a good thing. The less gain you need from the phono stage, the easier it is to get one at a lower price that sounds good.

Any good suggestion for preamp in my case? I have parasound A21 amp and Thiel CS2.4. My budget is ~ 2500.00

For that amount you could get a pretty great phono stage that should offer both MC and MM inputs and you can see what works best for that cart. You will also not be locked into only playing with MM carts, you could upgrade to the even the next step up in the Dynavector line the 17D which in my opinion is a lot better than the 20XH. The 20XL is even a noticeable imporvement on the 20XH at least it was for me. How about the Parasound JC3 phono stage? Looks like you are already a fan of Parasound products.

I think spending $2500 for a Phono pre with your TT is way over kill...You should look at a Musical Surroundings NOVA II. It is super quiet and will work very well. It costs around 1200 new.

What line stage are you currently using? Also, I agree with Ejlif. If you have $2500 to spend on a phono pre, it would make a lot of sense to go with a low output cart. I haven't heard the 17D but I have the low output version of your cart and its a very nice upgrade over the HO version.

I think he's talking about a full function with phono. The A21 an amplifier. There are a lot of great preamps out there available on the used market where you get a great amount for your money. ARC SP 16 or 17 is a great value used. You can often find a Joule LAP-100 for your budget. An Audible Illusions M3 series is a great starting place and that can be had for way less than your budget. Just be patient and wait for what you want to come up used. It will be well worth it. IMO those full function preamps outperform all those low cost solid state external phono stages like the NOVA or JC3 or PS Audio, etc.

Dhcod: Thanks. Yes, I am talking about a full function preamp with phono ...

If you do decide to go with a separate phono stage all you need for really great sound from a Dynevector 20X H is an MM level of gain.
I own one and use a Graham Amp 2 SE, and think it sounds fantastic. It is a dedicated MM stage but works really well with my HO MC cartridge. I wonder how much better the low output version could be given my satisfaction with my current albeit modest analog rig. It is just a VPI Scout with the regular JMW 9 arm and normal platter.

Since the A21 amp has balanced inputs, you may look for a used AtmaSphere MP-3 linestage with optional phono stage. They occasionally show up for sale at your budget and are quite good.