Is anyone out there Biamping their Proacs?

Regarding the Proac match with tube amps, that's not necessarily true.
Stuart Tyler, the owner of Proac, uses Sugden Masterclass series to listen to his speakers at the Proac Factory. I'd buy a pre-owned Sugden Masterclass int-amp( around $3,5k) and be done with it.
Sugden is one of the few brands you never hear about, because they refuse to spend dough on kitschy advertizing.

excellent info- sounds like sticking with one real nice tube setup will be the way to go.

Biker, the D15 is just a small two-way where biamping is really unnecessary. The upper amplifier would just be driving the tweeters. Get ONE higher quality tube amplifier with 50 watts or more and biwire.

The only way to even have a chance at decent, coherent, sound when biamping a two-way where the crossover is in the critical human hearing range would be with identical amplifiers. But why bother? It's not only a waste with this speaker, but is more likely to do harm than good.

A few years ago, just for fun, I bi-amped my Resonse 2.5s with a Cary 2A3 5wt SET on the tweeters and a Transcendent Sound 30wt OTL tube amp on the woofers. My room is 11 x 13.5 x8ft high. It was quite interesting and music was actually very enjoyable.

I run my ProAc 140 Studios, bi-amp from four VAS mono blocks tubes amps (50/25 watts). I also run the 140 center channel from a Cayin A77 (45watts), one channel for the top and the other for the bottom. The 140's are rated 91 db sensitive, with the sides in 8 ohm, the center at 4 ohm. Room is small, 12x13, so I do not need a lot of power.

Sound is great.

I don't know how low on the watts, ultralinear/triode) you could go. I run all amps in ultralinerar mode.

Sound is much better on tubes. I was running six vintage monoblock Marantz m5's, which run in Class A, 25 watts.

Tubes have a 'softer' sound.