temple audio mono blocks work really well with 57s and 63s-just a case of getting the impedance settings on the amp right.

The original temple audio bantam with both sounded gorgeous....not hifi flap your trousers-just delightful.

Colin Wonfors TQ Claymore and ewa m50 both worked really well.

OTA widgets helped with SS amps- took a bit of time to settle down though.