Try Yaqin MS-12B. You can get it at somewhere between $250 and $400. ;-) It worked better than my friend's Bellari with Chinese stock tubes.
I changed the stock 12AX7s to old used mullards and 12AU7s to old RCAs (paid $80 for both), and the sound got much better. It now sounds quite close to my friend's Audio Electronics ae-3 mkii.