Tubes for UNICO Amplifier

I'd like to upgrade the tubes in my UNICO integrated amplifier. The UNICO has a 12AU7 triode-based twin-tube input.

Any recommendation on what tubes might take the UNICO to the next level, the cost, and where I might purchase them?

Many thanks!
Buy a pair of telfunken 12au7's and never worry again?
hello dsc.
i agree with elevick, telefunk's from the late 50's to 60's
production are amazing tubes for the unico.
i realy enjoyed some phillips miniwatts (ecc82) production
from holland like amperex and siemens,very reliable tubes
with a real good sense of musicality,you can get a new pair
for around 50$ u.s.
telefunk's are the sweetest but some of the priciest too!
a mtched pair will go for 120 somtimes more!
tube rolling is great but everyone has his sonic preferency's. i simply reccomend that you should
buy a few pairs of different tubes and give them a shot!
the one's you do not enjoy you can probably sell back here
on audiogon,there is a good demand for 12 au7's.
my reply is a bit late but tought i would put in my 2cents worth!
I've tried Mullards, RCA Cleartops and the Telefunkens in my Unico. Bass with the Mullards seemed really loose. The Cleartops weren't any better and lost the midrange beauty of Mullards. The Teles tighten the bass and still preserved a beautiful midrange presentation. Despite the high cost, I've been very pleased. Purchased them through Upscale Audio in CA.