Denon AH-D2000 Headphones

What would be a good tubed (I'll consider solid state) headphone amp for these 25 ohm phones?
Regards, Sam
When I spoke to someone at, the salesman told me that a lot of the crew use Denon AH-D2000s He even offered me a great price but I was looking for pricing on some Shure SRH-940s.

If anyone would know, they could probably give you some advice.