Hi Dan,
That post by Raquel is absolutely correct regarding the importance of high quaility transformers and power supplies, they matter greatly. His suggestion of the VAC 70/70 amplifier is spot on, this was one great all time tube amp. It used 300b tubes in a push pull circoit and simply sounds wonderderful. keep in mind this is a directly heated triode tube(DHT) and not a pentode tube like the two amps you mentioned. The main downside to the VAC amp is the tube replacement cost for multiple good quaility 300bs(they do have a long life span however) but man oh man the sound! I do believe that the EAR 890 amp would drive your speakers very well, it does have very good transformers and power supply, just a different sound using the KT88 pentode rather than DHT tubes.
That post by Raquel is absolutely correct regarding the importance of high quaility transformers and power supplies, they matter greatly. His suggestion of the VAC 70/70 amplifier is spot on, this was one great all time tube amp. It used 300b tubes in a push pull circoit and simply sounds wonderderful. keep in mind this is a directly heated triode tube(DHT) and not a pentode tube like the two amps you mentioned. The main downside to the VAC amp is the tube replacement cost for multiple good quaility 300bs(they do have a long life span however) but man oh man the sound! I do believe that the EAR 890 amp would drive your speakers very well, it does have very good transformers and power supply, just a different sound using the KT88 pentode rather than DHT tubes.