Mcintosh vs Parasound

No pain, no gain.
Yeah, go for the Mac, 'cause it's pretty...

Sea2,
I've had the JC-1's and several Mac amps in my system. I could live with any of them. It's going to be which one draws you in more. Make the time to listen to both. People use analogies to cars and wine when comparing Amps. The one I use is: I've dated Pamela Anderson and Jessica Simpson. I prefered one, you might prefer the other. Nobody can tell you which one you will like best. If you get that, it will clear up alot of your confusion. I also see an amp and speaker sort of shaking hands together. Some amps and speakers like each other some don't. Doesn't mean one is bad. One thing about the Mac with it's autoformers, if you like its sound, you're probably covered with future speaker changes. Goof luck.

Here's the next question I have. As I said the YBA sounds wonderful. The sound is clear and transparent. It's only 100WPC. The speakers I have are about 90db. will these amps with their increased power make a big difference? My room size is about 14x16.

I had a pair of JC-1. I sold them. I think that 1000 hours break in is a lot of BS. This is electronics no mechanics...I think a lot of poeple can hear the hars parasound sound and then after 1000 hours they can tell de diference and then they feel that the amp "broke in". Non sense.
I bought a 602 and 252 in a bi amping setting with LS360. That sounds good!, Sweet, transparent, delicate. And punchy.
With a MX135.
Go for MC my friend

Actually, the break-in on JC-1's is more like 1400-1500 hours, and it's not BS.

My amps now have over 1600 hours on them and they are anything but harsh,
anyone who says these amps are harsh has problems elsewhere in their system, and that's not BS either.