Anyone listen to Zu Audio's Definition Mk3?

Spirit,
Here`s the pecking order.
1)CAST, Silver foil(uber expensive!)
2)CAST, copper foil(expensuve)
3)VSF Black, Silver or copper
4)VSF, Silver or copper
5)Alexander, entry level
Given the cost of your Zu DEF IV. and the level and cost of your system, I`d go with the CAST copper and be done with it. No 2nd guessing, CAST are made for high caliber systems,get the best.My Coincident speaker is very good but the CAST simply raises it to a higher performance level. You won`t regret this capacitor improvement.
Regards,

Charles, a pair of CAST Cu amount to about 10% the price off the spkrs, whereas CAST Ag appear to be special order everywhere, price TBA, my guess is maybe 2-3x the price.
You seem v. happy with the Cu, and I'm sure Sean of Zu will concur with you.
Unless he gives me a compelling reason to go down the Ag route, it seems that Cu will be it.

I went back almost a year's worth of Phil and other Zubie Def4 posts. I'm more than excited about the idea of the 4s I already own the Ibis so Zu will reterminate for free. Now it's time to work on the wife.

Warrenh, I can assure you, you WON'T be dissapointed. Whether you can smooth it over with the wife, that's another matter, the best of luck. You could always say it'll maintain your sanity in the twilight years making your relationship trouble free for years to come. Be prepared to buy her a bit of what she wants however.
Seriously, I stand by every word of my multi part review a few posts back, with the added comments that my indifference over the tweeter is fully resolved. The only down side is a tendency to bring out any OCD issues you may have - the 4s are such a transparent transducer that any changes you make will be fully heard, and of course this can go in the wrong as well as right direction. I'm finding toe in, bass adjustments on the spkr, and component supports/isolation (my choice is Symposium) making massive gains in SQ. I'm often 'in the zone' now, and I really feel this is one aspect of the upgrade merry-go-round I'm happy stepping off.

I like the wife strategy. Your posts, as well as Phils' are great. I should have read through them before I posted. It's really fete acomplais, but if you ever have additional info, please keep me posted. I'm sure Phil, though he may be busy chopping down his evergreen, will be perusing the Zu thread. Phil, it's been a very long while. You were my tube mentor. Took me over to the other side, and I am still greatful. Sounds like the Def4s will keep me in tubedom. love to hear from you. Thanks again.