You need to ask Zu owners, not amp owners. Unless you've matched amps with with Zu, which are totally unique, asking about amps is not just a waste of time here, you're actively seeking uneducated guesses.
I'm on my 3rd pair of Zu. I know what I'm talking about. Have tried many many amps on mine. Find Zu owners and pose that q to them. Better yet, ask Zu themselves when you buy yours.
I'm on my 3rd pair of Zu. I know what I'm talking about. Have tried many many amps on mine. Find Zu owners and pose that q to them. Better yet, ask Zu themselves when you buy yours.