I 've owned both the Bedini 25/25 and currently the Atmasphere S30 though I have not heard either with Quad 57. I can say that the Bedini 25/25 is highly regarded by Quad 57 owners as I was deluged with offers when I sold it.
That being said, I would second the recommendation for an Atmasphere OTL. Would recommend the M60 but you could use the S30 if the stacked Quads were wired in series (increasing the overall impedance).
That being said, I would second the recommendation for an Atmasphere OTL. Would recommend the M60 but you could use the S30 if the stacked Quads were wired in series (increasing the overall impedance).