My only gripe with my Andra IIs is it requires a high current amp to make it sing so playing with low power amps is not an option. I came to the same conclusion as Ontjesr after auditioning several more expensive and efficient speakers.
Coxhaus, I find my Sonic Frontier Power 3SE+ works well with the Andra IIs. After the mod using Reissued GL KT88 and NOS Philip Holland e88cc SQ, it produces 268 watts and able to drive the Andra to satisfying levels.
Bass and dynamics were better with my Krell FPB600 but inferior in all other areas. I sold the Krell ahortly after the SE+ mod.