There is not one. Just go for quality, best low end, best treble etc. You like tube high end, but maybe you like SS bass. Forget about power although the more you can afford the better.
What’s the Right Power Amp Ratio For Bi-Amping?
Is there a “golden rule” or rule of thumb when selecting amplifier power in a bi-amp setup? It seems to me that the power should be apportioned according to the demands. Since most of the energy consumption in sound reproduction is by lows, it stands to reason I should use a much more powerful amplifier for lows than highs, but what ratio of power? 2:1? 10:1? Is there a wrong answer?