Mono Block tube amp or Stereo Tube amplifier?

Start with why you want tubes. Then think about how much you can spend. Personally I believe that tubes are for acoustic music. I see no reason why anyone would benefit from reproducing heavy metal at 95 db with tubes. That is SS territory. Tubes are for sensual, subtle sounds.

If you still think you want tubes, or if you now see bi-amping with SS works better for you, the rules are the same. Two chassis cost more than one. Monos enable you to shorten speaker runs. Monos, even if they share a chassis will have separate power supplies allowing for better separated channels. Then there are layout implications, bragging rights and forum topics.

Remember, though, that bi-amping is not a goal but a means to reaching one's goal. Unless you need to do it, don't bother.

Almandog in your current setup I would always look at keeping things simple therefore, a sweet midrange/treble stereo tube amp is preferred IMO. If your truly going to commit to a tube amp you really have to select an amplifer that will help bring synergy and sonics you truly want in the midrange/treble area. I agree, tube rolling will allow you to change the sonics for Legacy Audio 20/20 (nice speaker BTW).

I wonder how much you really gain with MONO amps in the midrange/treble in your current setup. Most great MONOS will cost a lot so look at price/performance ratio hence, stereo tube amp may be a better cost alternative. Tube rolling alone for my two MC275 run in mono...$800 plus to do it right.

The key here is the external crossover which has to deal with two different amplifiers and the potential gain mismatch. The independent output-level controls will have to balance the levels between the woofer and midrange/treble amplifiers.

Almandog, The Onix really is more a power amp than an integrated. I use a preamp in front of it and it sounds great.

Macrojack, is this why Rush uses tubes? My point is that watts is watts, and tubes do just fine with any type of music : )

Check out -Antique Sound Labs- Hurricane, 200 watts per channel in standard mode and 100 watts per channel in triode mode. They are monoblocks and should work well for your application. I have only heard them run full range and not on your speakers, but they sounded very nice in the triode mode.