Help My Krell amp is too big.

You must have forgotten the proper sequence to getting things done - You build your new home to fit your audio system and not the other way around :-).

I would suggest you not sell off your Krell but instead try to work with what you have. Firstly they are good amps and secondly it is not advisable to place your power amp in an enclosure. You'll going to have heating problem, regardless of whatever amps you are going to get. The only amp I know that does not get too hot are the McIntosh because they are class B amps. If you insist on fitting your amps in your cabinet and the McIntosh sound fits your taste, you might want to give it a shot.

Bust out the back of your stereo cabinet. Have a carpenter bust it out and expand it into the stud wall, there's atleast 4" hidden back there. I've seen it done for TV's, why not your amp?

Will the stereo cabinet allow for adequate ventilation of your Krell?

If you like Krell sound why not stay with Krell mono?

Unless you are in a shear-wall configuration it should be easy to get a few more inches in depth.

You you need to have a converation. Lots of suggestions hereabouts if you contractor can't think 'inside the box..'