If you don't have a balanced preamp, don't waste your time/money buying a balanced amp.
I personally think 2 Adcom 5500s would be fine driving these.
If I remember correctly, some of these Kappa speakers had a difficult to drive crossover scheme, that can be modified to make them easier to drive.
Adcom 5500s can be bought here regularly for under $500.00
each. Try to find later production with IEC power cords,
then you can tweak the sound easily...
I personally think 2 Adcom 5500s would be fine driving these.
If I remember correctly, some of these Kappa speakers had a difficult to drive crossover scheme, that can be modified to make them easier to drive.
Adcom 5500s can be bought here regularly for under $500.00
each. Try to find later production with IEC power cords,
then you can tweak the sound easily...