best preamp for a MC-252 for under $1500

It could be your power. New power lines usually only cost 2 to 400. Only you'll be able to tell if it's the power. You may consider getting a power conditioner like a Powervar or Oneac for the cd player and see if that helps. The power supply in the Mcintosh is no doubt excellent and may be why you're not hearing the problem with that amplifer.
When it comes to speakers you'll find alot of different tastes. Many companies these days make great speakers for the money. There's a few at audiocircle.com that are standouts as well as other companies that sell direct so they have no advertising or middle man markups. You'll have to find the reviews on these stars yourself. Ask here as well as audiocircle and audioasylum and then do some research. Most importantly take your time.

Great advice-hardest to heed. I looked at the JM Labs and the Thiels. Thier flagships were the ones that fit the requirements. The rest were 100w-150w or less, which would not be a good choice. I am afraid to ask what the prices were. When I hear something that sounds crisp and clean highs and tight, quick, full, lows...I want to hear it as loud as can be, without feeling that I am stressing any piece of eqiupment. One thing is for sure though...I CAN study.

Don't get hung up on the power requirements for speakers. The 100W-150W numbers don't really mean anything as long as your amp doesn't clip - which your won't (power guards keep it from ever happening).

The flagship JM Lab and Thiel speakers can get very VERY expensive so you may want to consider some of their lesser modesl that are actually higher value. Arthur

First let me qualify this by stating I've been a dealer for 2 mos but have owned VMPS speakers for 9+ years and have been recommending them as a must listen for years. Rather than take my word for it here's a list of current reviews:
http://www.audiocircle.com/circles/viewtopic.php?t=13112
Also the RM 40 won Best of High End at CES 2002 and runner up in 2003. These will handle all the power you have from the RM2 on up and sound excellent doing so.