Well frankly it's not how much power you throw at the 57's, which is where many go completely wrong....they can only handle so much to start with, I've tried 80wrms PP tube grunt which did not even remotely do any justice to what these remarkable speakers can impart...as previously mentioned the EAR amps are optimally suited to the Quad load, this is more important than mere watt figures will tell you.
My room is 4.5m w x 6m open ended continuing into an open plan area, the EAR 869 was more than sufficient and the bass was superb...dynamics is relatively limited on any Quads regardless of how much power you try to bludgeon them with !
Having said that, I've spoken with other owners who swear by the pairing of 57's with the EAR 861, which is a PP version of the 869, delivering twice the output power per channel.
Whatever you do, if you can have the opportunity to audition the 57's with any EAR amps, I'm sure you will be very impressed.
From personal experience I think the pairing of 57's with the right SET amp such as the 869 is one of the very rare combinations which allows you to enter the 4th dimension of sound such is the tangible palpability...I sat a friend down to listen to Jazz at the Pawn Shop and he literally stood up and looked all around for hidden speakers saying how freakily present the ambience was, as if one was sitting inside the actual venue and partaking at the bar...indeed it is profound how betwixt these two items of electronics from Huntingdon, UK, music is conjured.
