If your Arcam has pre-outs and main-ins, then you can use its preamp output with the Mac amp, and the Mac preamp with the Arcam amp. Might give you an idea what each of your new components sound like individually.
Second, you might play around with a couple of different output taps on the amp.
And I'll second other's advice about giving it some time . . . when you've spend a pile of hard-earned cash new electronics, mental expectations can be tricky to sort through. But on the other hand . . . if you don't like it, then you don't like it. McIntosh is very fine equipment, and their manufacturing quality is definately better than what you get from Arcam . . . but that doesn't mean that at the end of the day, YOU have to like it better.
At the very least, Mac stuff holds its value very well . . . so I wouldn't regret your purchase.
Second, you might play around with a couple of different output taps on the amp.
And I'll second other's advice about giving it some time . . . when you've spend a pile of hard-earned cash new electronics, mental expectations can be tricky to sort through. But on the other hand . . . if you don't like it, then you don't like it. McIntosh is very fine equipment, and their manufacturing quality is definately better than what you get from Arcam . . . but that doesn't mean that at the end of the day, YOU have to like it better.
At the very least, Mac stuff holds its value very well . . . so I wouldn't regret your purchase.