The closest approach...really

Mrtennis, yes, that would be a nice test for everyone -- I think we're deeply biased in the way we listen to our equipment. In the end what matters is the survival test: how long has amplifier x or speaker y lasted in my system? If it's more than 1 year, then it means our ears really like it. If after a few months I begin to question it, then it means there is something wrong. In my case, so far the two things that lasted the most are my EAR 868 power amp and my ESL 57.

In my prior post I meant my EAR 890...the 868 is something I am now considering.

Hearing "many" combinations does in no way, shape, or form mean that proper integration of panels and subwoofers cannot be achieved.

There are many combinations that do perform wonderfully.

In this particular case maybe more listening experience is required.

Generally the saga goes, that if tubes are used with the Quads, the subs would perform best with SS. Actually blending solid state driven subs with tube driven stators is very difficult indeed. It is much easier to use tubes also for the Gradient subs to get an excellent coalesced rendering, using Gradients own active x-over but only for the bottom end and letting the Quad 63s go all the way down. After much fiddling, listening and moving the whole shebang around ( for this purpose the Quad-Gradient combo was put on wheels and the listening position bolstered with cushions to get the ears in the right height) a practically perfect blend was achieved.

Detlof, your comment about using pillows to get the ear to the right height reminds me of my struggles to get it right. As I said in my prior comment, I ended up bending the 57 slightly forward. That changes the radiation pattern so that you don't have to use cushions or anything like that. By the way, I use a digital source to drive the gradients, and a tube amplifier to drive the quads. I don't think the gradients are terribly sensitive to the amplifier you use...just use something that is more than 50W per channel and you're ok.