Tube + SS bi-amping B&W 803 D3s?

Best of both worlds if you can dial it in.  Tube rolling will likely become part of the fine tuning once your tube amps are in, but that's one of the benefits of having tubes.  You'll need the ability to adjust gain on both sets of amps.  

I'm running Dyna/VTA monoblocks from ~ 60hz up, and use a silver mica caps as an inline high pass filter so that the amps don't have to produce the bottom octaves.  

Good luck!


 

The mixing of amps is indeed another variable, but I don’t think I’d go as far as to say it almost never sounds right.  It depends, and it certainly can sound right...and even better, which is what makes it enticing to try.   

The crossover frequencies where the amps pass off the signal, gain matching, polarity shifts, and the characteristics of the amps themselves come into play.  You might hit the setup on the first attempt, or at least may find some satisfying improvements, but if not there are still a lot cards that can be played to dial it in.  Tube rolling can make a notable difference, but the real changes can  happen if you opt to start bypassing passive crossovers and implement active crossovers or inline filters.  

Point being, you won’t know until you try.  If you’re willing to make the effort, there are some spectacular potential results to be had.  It doesn’t have to happen all at once to be a fun and successful endeavor.  One step at a time.  

My bi-amping started with two identical modified Dyna/VTA stereo amps  in a vertical configuration...one on the left, one of the right, and it improved the separation quite a bit, and the clarity somewhat compared to a single stereo Dyna/VTA 70 amp.  It still had the bass that a modest tube amp driving a 4 ohm load offers, so later on I switched to a horizontal setup and added an integrated amp to handle the woofers, while the tube amps fed the midbass and tweeters.  That led to me bypassing the passive crossover of the woofers and adding an active low pass crossover, which allowed me to adjust the crossover frequency and vary the gain....a notable improvement in bass and overall clarity to the tube amps and midbass/tweeters too.  The next step was to install an inline high pass filter to the tube amps to eliminate their responsibility of producing the bottom octave or two to the midbass...another very notable gain in overall clarity to the whole frequency range above that (~60hz).   All in all, it is considerably improved in several areas compared to just a single stereo amp....at least in my case.  Different situations, and likely different approaches required, but the potential remains if you wish to pursue it. There are typically solutions for every perceived issue. You’ll learn as you go, and can take it as far as you want to.  

@emergingsoul 
I’ve read similar things, but haven’t researched it much, so don’t claim to  understand the technical ramifications of that.

My motivation was the potential for improved clarity by way of reducing the demand on the amps and the midbass drivers from producing the large and power sucking lower frequencies, but if it prevents the transformers for letting out the magic smoke, all the better!   

The active crossover could have provided the high pass filtration to the tube amps with some added flexibility, but was concerned about the noise floor.  The silver mica caps seemed the simplest approach with good signal integrity and low noise.  Really happy with that simple mod.