I have several thoughts on this discussion, but one thing stood out for me:
You are saying that you use this system as sort of a "mastering reference' for recording and mixing. I would keep in mind that the Klipsch speakers are very excellent and sound very "live" and "lively", however the horn drivers are very forgiving and soft in the high frequencies. This means they are not as clean/clear or as ruthlessly revealing as other speakers. This may not be what you want if you are "checking the master mix". You really want to make sure your mix sounds good on an extremely revealing system as well as a budget low end system (at least that's the goal, right?).
That being said, if you switch out the speakers, you may find that the Cambridge will sound rather solid-state and sterile in comparison to what you heard with the Klipsch horn speakers. So, it may come down to replacing both the speaker and the amp. It depends on how important the "enjoyment" of the system is to you. Or if you are just using it as a "tool for master mix check". Or, you may end up liking the Cambridge just fine with new speakers. I would also agree that tube amp is not the answer as tubes will generally be even slower and warmer sounding than solid state. As a listener, the combo with Klipsch may be very nice to listen to, but keep in mind that tubes can also be very colored sounding and will not be as revealing as solid-state.
He's got a set of studio monitors but often we need to check our work on this Klipsch Forte III hifi system.
You are saying that you use this system as sort of a "mastering reference' for recording and mixing. I would keep in mind that the Klipsch speakers are very excellent and sound very "live" and "lively", however the horn drivers are very forgiving and soft in the high frequencies. This means they are not as clean/clear or as ruthlessly revealing as other speakers. This may not be what you want if you are "checking the master mix". You really want to make sure your mix sounds good on an extremely revealing system as well as a budget low end system (at least that's the goal, right?).
That being said, if you switch out the speakers, you may find that the Cambridge will sound rather solid-state and sterile in comparison to what you heard with the Klipsch horn speakers. So, it may come down to replacing both the speaker and the amp. It depends on how important the "enjoyment" of the system is to you. Or if you are just using it as a "tool for master mix check". Or, you may end up liking the Cambridge just fine with new speakers. I would also agree that tube amp is not the answer as tubes will generally be even slower and warmer sounding than solid state. As a listener, the combo with Klipsch may be very nice to listen to, but keep in mind that tubes can also be very colored sounding and will not be as revealing as solid-state.