Maybe something like push pull KT88 with some power behind them? The JBL you mention is very efficient but the large, stiff woofer is what needs the 100 watts the factory suggests.
Your Crown amps with their high damping factor would be great for controlling the JBL woofer, but as you said, pretty dismal for the horn drivers.
Depending on how loud you listen and how much control you need (personal taste) you could do with as little as Dynaco Mk 3 mono blocks with KT88 (60 watts), all the way up to Atma-Sphere MA 1.5 or VTL 450 mono blocks.
Of course there are much sweeter transistor amps than the Crown. I would not be surprised if the new Rowland might not sound really good with these old JBL's.
Your Crown amps with their high damping factor would be great for controlling the JBL woofer, but as you said, pretty dismal for the horn drivers.
Depending on how loud you listen and how much control you need (personal taste) you could do with as little as Dynaco Mk 3 mono blocks with KT88 (60 watts), all the way up to Atma-Sphere MA 1.5 or VTL 450 mono blocks.
Of course there are much sweeter transistor amps than the Crown. I would not be surprised if the new Rowland might not sound really good with these old JBL's.