I had used KSA 150 to drive Apogee Duetta Sig from 1989 to 1999 with satisfaction.
I also auditioned KSA 250 at dealer’s showroom but it was too heavy and beyond my budget on 1989.
But I ditched KSA150 after switching from Duetta to Avalon Ascent II.
It sounds too bright with Ascent II.
You had better check synergy with your speaker rather than blind purchase.
Also it may need re capping as mentioned by roxy54
I also auditioned KSA 250 at dealer’s showroom but it was too heavy and beyond my budget on 1989.
But I ditched KSA150 after switching from Duetta to Avalon Ascent II.
It sounds too bright with Ascent II.
You had better check synergy with your speaker rather than blind purchase.
Also it may need re capping as mentioned by roxy54