plz suggest a tube preamp to match Parasound A21 amp

Hi, I'd like to add some tube attitude to the signal entering my Parasound A21 amp. Plz suggest decent tube preamp under $2,500...New or used, but no 20-30 years old, vintage stuff plz. Fully balanced design is preferred. Combined XLR / RCA inputs/outputs are necessary. Recently tried Schiit Freya Plus, but didn't like it due to weird volume control function and delayed start. Tnx.

Check the output impedance of the preamp because the A21 has an input impedance of only 33kohms. I was in the same situation and the low frequencies were MIA
If Balanced input of A21 used the impedance is 66 kΩ..... 33kΩ is for RCA input only. 
05-09-2020 8:58pm
Don’t know about the AR Ref 2 with Pass amps, but I’m pairing the AR Ref 3 and AR Ref 5SE with Parasound Halo A21 and JC2 monoblocks with incredible results - hard to believe. Just incredible clarity, detail, resolution, imaging and soundstage with superb tone, tenor, texture and bass control - a very holographic, live sound.

I’ve been surprised by this combination - though, I suppose some of the credit must go to the Bryston BDP-3 & Schitt Yggdrasil DAC, which sound superb, even without the AR tube line stage - but, the tube line stage improved upon that combo even a great deal more. And... with either the Harbeth 30.1’s with Townshend Super-Tweeters, or Linkwitz Orion’s - to the point, that I doubt I could improve upon the sound a lot more. I’ve also been surprised that this combo has really awakened the 30.1’s, which initially hadn’t impressed me, but now have much better highs, resolution, and bass control with the Harbeth rich, organic sound.