My vote goes for the NAD. I have not heard Cambridge Audio but I do own Arcam.
I just received a 315bee to power Studio 40s v4. It's bit early to talk about it as the amp has been playing for only 15 hours, but I can say that, right out of the box, it is distinctively heavier on the bass / upper-bass frequencies compared to arcam (arcam maybe the same as cambridge audio with a higher price tag). Much much warmer. Another thing that striked me is how much more detail it reveals. Really, this little NAD could make the 3x more expensive arcam pass for a bestbuy superstore brand. In any case, burned-in or not burned-in, it plays loud without shouting, it is very musical, and it feels a lot more dynamic/powerful than 40wpc. Very nice indeed. I do not know yet if I need more power; I will make the decision to keep it or to get the 326 next week.
I just received a 315bee to power Studio 40s v4. It's bit early to talk about it as the amp has been playing for only 15 hours, but I can say that, right out of the box, it is distinctively heavier on the bass / upper-bass frequencies compared to arcam (arcam maybe the same as cambridge audio with a higher price tag). Much much warmer. Another thing that striked me is how much more detail it reveals. Really, this little NAD could make the 3x more expensive arcam pass for a bestbuy superstore brand. In any case, burned-in or not burned-in, it plays loud without shouting, it is very musical, and it feels a lot more dynamic/powerful than 40wpc. Very nice indeed. I do not know yet if I need more power; I will make the decision to keep it or to get the 326 next week.