Mcintosh vs Parasound

I second Perfectionist on this!
THEY DO TAKE UPWARDS OF 1,500 HOURS, and this is NOT BS!
Mine have also got about 1,600 hours on them, and they sound awesome.
To prove my case, I have a friend who owns a pair with only about 400 hours on them. We unhooked mine and put his in my system. Mine sounded MUCH BETTER! He totally agreed, and could not believe they were the same amps.
His sounded thin, in your face, and had virtually no image depth to speak of. Mine sounded much more neutral, faster, more transparent, more detailed, and had deeper, more powerful, and tighter bass response, and a much deeper soundstage.
They will reveal weaknesses in any of your other components, if they are not up to par. Better use quality components with these amps!

I don't know. But I'm sure if Bob Crump reads this, he will provide some insight.

more powerful YBA? you may miss the fine sound of the yba integrated when compared to Mac and Parasound.

I second the recommendation for the MC402, but it does need break-in time as well. My MC402 sounded steely in the highs for the first weeks with my Shahinian Diapason, only after easily 200 or 300 hours did it develop the natural, sweet sound that McIntosh is famous for, and which I enjoy for 2 years now.