B&K 220M vs. Ref 7250 for 2 ch.

I have the B&K 4220Ms: monoblocks @ 250wpc; they are an exceptional value. However, the 7250 is excellent, as well. I recommend standing firm, unless your speakers are running out of amplifier. The 7250 generates 180wpcs, all channels driven. While this seems a lot, what you lose is the headroom of the 220M: B&K designs its monoblocks with high-peak capability.

In the end, it comes to the efficiency of your speakers, and the type (and volume) of load (HT vs. type of music).

My fronts are Dynaudio Contour 3.3, rated 89db/w, 4 ohm, for HT is fine, but have to up the volume a little for music(classic, jazz, vocal.), what's output of 7250 for 2 channels driven? higher than 180wpcs? how is the sound of you monoblock compare to other B&K models? thanks!

The 7250 will provide the rated amps (220wpc, I believe) into 2 channels @ 8 omhs; into 4, they'll go to 350, again, I believe. Offset this with the 89db, which is one or two below the 'norm'.

It works that you set the volume for clarity and articulation: fancy words for hearing all of the music. Also, it works that HT is less precise than music: we know the music: Beethoven's sixth or Brubeck's Take Five. As such we can tell when music is 'missing'. HT is not this way; other than voice, we would only miss the big stuff.

This becomes a financial question, although less so with the reasonably-priced B&K components. If you are serious about your music: sit quietly for hours listening to Miles and other wail, soulfully counterpointed by piano: then by all means go get some headroom and articulation.

One alternative is to get another 7250, then bi-amp the Contours (if you can) in a Passive, Horizontal manner: put a Y connector comming off your pre-amp for each channel, then run the 5 channel output from one amp to the LFs of the Contours, and run the other 5 channel output to the HF. This will improve imaging, as well as ensure that the LF & HF have enough juice (and the Contours have the necessary terminals). Again, it depends on your wallet.