Need a power amp for a pair of ATC SCM 11's

FWIW, I'm currently using the same Wyred ST 500MKII which I found used. Love it a as great all around amp, flexible and easy to transport. I also have the STP-SE so it prob helps that I've kept things in the family and can run fully differential.

I've used it with a few pairs of speakers (incl bookshelfs) and it always sounded good. I used to right next to SYVANE 50 watt monoblocks and to my ear it was not outclassed. The bass seemed better than the tube gear, maybe a bit more definition with the Wyred but the tube amps seemed to have a slightly larger soundstage. The Wyred was not blown out of the water which was really what I wanted to check out. 

I was running a Forte Model 3 before this and the Wyred seems better all around for my use. Enjoy. 

The Quad 909 is a nice neutral amp slightly on the warm sound . It would be a nice match with the ATC . 
Another option used would be a Mccormack if you can find some on the market as they dont show up very often .
What ever you get remember the ATC need amps so go with a amplifier capable to give a lot of current . Dynamics will suffer if not .

Thanks so much everybody for the feedback, this is so helpful and informative. What a great community this is. 

Seems like both the Wyred and Quad options a solid, so it's just a question of whether I spring the extra for a brand new bit of kit.

I think I'll go with the Wyred ST 500MKII, just need to 'massage' the price down a little when presenting to the missus:)

Unpopular idea but I suggest you wait, save up to where you can spend
$2,200-$2,500 and buy a used ATC amp. Why? Equipment synergy is a very real thing. Those ATC speakers are ruthless when it comes to GIGO.
Just a thought. Patience is rewarded especially in this endeavor.