Thanks for the input so far. Yes, I am looking for a bit of that “tube magic.” Switching to a tube preamp has made the music seem so much more alive, with more depth, possibly due to hearing more harmonics from the various instruments.
I now understand that I do not need anywhere near 100 wpc for the mids and highs, that probably 30 to 40 watts will be more than sufficient in our roughly 13 x 20 x 8 living room, open on one side to the dining room. A higher power tube amp would just give me power reserves I probably would never use; we like to listen at moderately loud levels—just beyond where the speakers “open up”—not very loud levels.
Someone commented that the crossover will handle gain matching between the two amplifiers, which was a major concern.
One thing I do not understand is the need to remove or disconnect internal crossovers when using an active external crossover. My speakers have two sets of binding posts, one for lower frequencies and one for mids and highs. When a manufacturer builds a speaker this way, do they not bypass at least the crossover divides the lows from the mids and the highs? (In the F702s, that would at 250 hz.). If not, what is the point of two sets of binding posts? Thus, it would seem to me that if I set the active crossover at 250 hz I am simply duplicating the internal crossover point and sending just frequencies below 250 Hz to the woofer, which is what the internal crossover does; frequencies above that are directed into the “upper” binding posts, and it seems to me that I would want to retain the internal crossover dividing the mids and highs (1.7 kHz in this case) because I am only bi-amping, not tri-amping. OR, are we getting into the “magic” of crossovers with the possibility of some undesirable interaction between the internal crossover at 1.7 kHz and the active crossover? Can someone explain.
As you can tell, I am new at this, and I greatly appreciate your advice. My current system is far beyond what air replaced in the past year—Infinity Modulus satellites (the 1992 quality model with EMIT tweeter before Infinity went mass market) and a NAD C356BEE used as a preamp feeding into a McIntosh MC2125, of which for the latter I was the original owner. I am looking at tubes for the upper end to see how much better I can make my system without spending gobs more money.
Many thanks, folks. Good listening to all.