XA 100 should drive the ESL 63 very well; likewise with the 9series.
I prefer the later 63s to the new series -- but keep in mind that the new Quads play louder and more extended than the 63s.
An old trick is to use two pairs of 63s one on top of the other, on either side... if you find cheap 63s it's worth it. Regards.
I prefer the later 63s to the new series -- but keep in mind that the new Quads play louder and more extended than the 63s.
An old trick is to use two pairs of 63s one on top of the other, on either side... if you find cheap 63s it's worth it. Regards.