It is not uncommon for people to biamp with tubes and solid state, attempting to combine the advantages of both.
If you passively biamp, it is very important that the amps have the same gain. If the amps don't have the same gain, it would require a mod to one of the amps, which should be able to be done by any competent technician.
If you actively biamp, using an external, electronic crossover to bypass the speaker crossover, not only do you have to make sure that the gain matches, but you have to bypass the speaker crossover. This will require surgery to your speakers unless have something like Linn speakers, where you bypass the crossover by connecting to different speaker posts. Even if you did do such surgery on the speakers, it is possible that it could sound horrible. Speaker designers will match the crossover to the drivers and cabinet that they are using. If you bypass their crossover, who knows what will happen since the designer did not intend such a use when designing the rest of the speaker!
From your post, however, I am assuming that you are simply talking about passive biamplification, so it's just the amp gain that you have to watch.
Using Linn equipment, which is designed to biamped, I found passive biamping to make a small, but noticeable improvement. Active biamping, on the other hand, is a huge upgrade.
If you passively biamp, it is very important that the amps have the same gain. If the amps don't have the same gain, it would require a mod to one of the amps, which should be able to be done by any competent technician.
If you actively biamp, using an external, electronic crossover to bypass the speaker crossover, not only do you have to make sure that the gain matches, but you have to bypass the speaker crossover. This will require surgery to your speakers unless have something like Linn speakers, where you bypass the crossover by connecting to different speaker posts. Even if you did do such surgery on the speakers, it is possible that it could sound horrible. Speaker designers will match the crossover to the drivers and cabinet that they are using. If you bypass their crossover, who knows what will happen since the designer did not intend such a use when designing the rest of the speaker!
From your post, however, I am assuming that you are simply talking about passive biamplification, so it's just the amp gain that you have to watch.
Using Linn equipment, which is designed to biamped, I found passive biamping to make a small, but noticeable improvement. Active biamping, on the other hand, is a huge upgrade.