Mark:
The answer is yes, it can be done. You will need an active crossover and need to bi-pass the internal cross-over of your MLs when using two different types of amps. Undoubtedly the gain will be different. I have a pair of ML monolith IIs which I bi-amp--to great success. I'm using solid state on both top and bottom--but your idea is a good one. I have tried using a tube amp on top and it didn't work, but that was because of the great mis-match (in power) in the amps I was using. Your tube amp needs to have close to the same output and needs high current delivery to handle the panels (this is generally not a problem for most good quality tube amps). I would recommend no less than 100 watts per channel (per driver as well). In terms of cross-overs, Bryston 10B and the Marchand are both excellent. The Marchand is a bit more economical.
Lastly, if you are using a class A SS amp and the tubes--better have a good air conditioner or live in Canada--you are going to generate some heat.
The answer is yes, it can be done. You will need an active crossover and need to bi-pass the internal cross-over of your MLs when using two different types of amps. Undoubtedly the gain will be different. I have a pair of ML monolith IIs which I bi-amp--to great success. I'm using solid state on both top and bottom--but your idea is a good one. I have tried using a tube amp on top and it didn't work, but that was because of the great mis-match (in power) in the amps I was using. Your tube amp needs to have close to the same output and needs high current delivery to handle the panels (this is generally not a problem for most good quality tube amps). I would recommend no less than 100 watts per channel (per driver as well). In terms of cross-overs, Bryston 10B and the Marchand are both excellent. The Marchand is a bit more economical.
Lastly, if you are using a class A SS amp and the tubes--better have a good air conditioner or live in Canada--you are going to generate some heat.