most clear, crisp sound power amps, monoblocks ?

You want LIVE music, very easy. Buy or keep all your cables with the same manufacture. Don't ever mix your audio system with different brands or generation. Your amp watt ratio must be at least 1.6 more the speaker max rating. If you buy the speaker rated 50 to 350 watts. your amp must be 500 watts or more. High end sound does not have to be high price. Just don't mix them up. Set your budget and start shop for new brand that you can afford.

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Narciso, whenever vague questions appear, they are meaningless without revealing your budget. Let us know what your budgetary range is and you'll get specific answers. Your question is too broad and vague without knowing your budget.
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Compared to what, at what price, with what speakers?

Pass Xs 300's should fit the bill,but you should pair it up with the Pass Xs Preamp to get the full benefit!

It depends how much money you can spend. But money does not garantee you a good live sound. In almost 16 years of time I also encouterd many highend sets with a poor endresult.

The combination of the right tools togheter ( sources, speakers, amp, pre amp, cables, conditioner etc) can create a live and realistic sound.

Acoustics of a room are the biggest enemy of a set.

When you have a system with a bigger freq. response, you can create a more live like sound. It is all about making the perfect combination of tools. I call it the art of sound.

I wrote a personal view in how I see a blueprint of the absolute sound. I call it Total sound.

http://forum.audiogon.com/cgi-bin/fr.pl?rcabl&1393266431

In my personal opinion Pass Labs also make the most complete sounding poweramps.