Jadis JA30 Mk2, how great???

Got it. I'm not really a fan of 300B single ended amps. Not because I don't think they sound good, but more because they are so very limiting as to the speakers that you can match them to. Plus, I think in many cases the 300B tube is more susceptible to noise from microphonics. 
In that perspective, I much prefer an 845 ( which Jadis also makes).

Jadis is  one of those companies that just consistently has  the knack of  building beautiful sounding emotionally engaging amplifiers that connect the listener to the music. There's obviously something they understand  and are executing  right.  

I'm a 300b SET aficianodo through and through. I haven't the opportunity to hear the Jadis SET offerings but I'm confident that they got it right. I heard a Jadis el34 push pull integrated (Not even one of their higher level models)  and it was very good sounding.  It displayed that special ability to pull you deep into the music..

It they can achieve this level of sound quality with an el34, I can imagine what they're capable of with a 300b in their  upper level range of mono block amplifiers.  As daveyf noted you just need the appropriate speaker matchfor the amplifier. 
Jadis is exceptionally adept at reproducing music beautifully. 
Charles 

Indeed, Jadis does make beautiful sounding and emotionally engaging amplifiers. To that, I think their build quality is basically second to none.
IMO, if one is looking for a tube based amp, then these need to be on anyone's short list.

Thanks all for your comments! I have just found how good the JA30 sounds, so arouse me of much interest to get their 300B amp as well. But honestly it seems can't bring enough power for my Sony AR1 speaker which was also newly bought! Anyway I will run them well for the next couple of months to see how changes they will be! 

Hi samhvcc,
As I wrote earlier I’m a hugh fan of SET amplifiers. Matching them with the appropriate speaker is crucial for a successful outcome. Sam I don’t believe that the Sony SS AR1 is designed with the intention to be driven by SET amplifiers.

It a 3 way, 2 crossover (Multi slope per Sony)
4 ohm nominal load (Drops to 2.7 ohm in upper bass and part of the midrange per Stereophile).
88db sensitivity .

Now I’m a proponent of the "Listening is superior to relying on the measurements " philosophy . However specifications/measurements can be used to help develop some initial idea of potential compatibility of matching audio components.

The Sony seems to be a challenging speaker match for most SET/PSET amplifiers. It seems it was built to be driven by higher power/current capable type of amplifiers.
Charles