Be mindful of the output impedance of any tube preamp you might consider. It needs to be relatively low (I'd suggest under 200 ohms) to produce deep, articulate bass from the XA-30.5.
I used a Lamm LL2 Deluxe with good results (and it's in your price range). Also, a Juicy Music Peach worked quite well.
I used a Lamm LL2 Deluxe with good results (and it's in your price range). Also, a Juicy Music Peach worked quite well.