I'm using a Marantz PM8004, and it drives them quite well, but the only comparison I have for them would be an old gutless Denon AVR unit I've since sold. So no help on the Cambridge in specific, though the Cambridge you mention and my Marantz are roughly even in terms of output. 75 vs 70w @ 8ohms. Which is more than enough.
I might spend a little more on an amp though since they generally last quite a while if upgrade-itus doesn't come into play.
And let's just hope it was only a spot of bad luck and nothing more with your 404s.
Cheers.






