Best multichannel amp for quality stereo listening


We recently adopted a teenage boy and I'd like to adjust our living room system to better accommodate his movie watching tastes. I'm pretty happy with our current two channel system for music as well as movies (no action based movies until now) so, in this modification, want to keep this level of quality for music.

For a preamp I'm currently using a Peachtree Audio Nova which I will keep for music sources because of its large number and types of input choices. The current amp is a Peachtree 220 and the speakers are the Martin Logan Ethos' which I will keep as the front pair. The decision I need to make, then, is which multi-channel (5 is enough) processor / amp to buy. I still have an old B&K AVR307 that I used for surround listening years ago and which I could adapt but I would like some assurance that I will not lose any of the sound quality that I presently enjoy.

I assume there is a way to keep the current power amp in the system for 2 channel music listening but am having difficulty trying to envision volume control in a split system such as this would end up being.
128x128broadstone
I apologize for changing the nature of my original post here, especially after having received well thought out responses, but I just discovered that the Nova does, indeed, have an HT bypass function at one of the aux connections. I didn't even know that there was such a thing before your post, Kr4, but that being the case, your recommendation makes sense and will be my approach.

My next move, then, is to get the B&K AVR307 out of storage and determine whether it has L/R line out connections. According to the manual it has several line out connections but I'm not sure that any of them are for delivering L/R channel signals. If so, even though it's old, the B&K is still a pretty good performer; if not, I'll look for one that does.

Anyway, I'm still open to and will appreciate all suggestions.
If the B&K does not work for you, consider looking at the Emotiva XMC-1 multi-channel preprocessor. This is a *very* capable unit and is only $1995. It can easily compete with units costing $10,00 - $12,000. Plus, it comes with a 30 day in-home trial and a 5 year warranty - w00t!!

https://emotiva.com/products/pres-and-pros/xmc-1

-RW-
If you're trying to simplify your system, I don't know if using the B&K is your best choice if it has no HDMI input as you may encounter some cumbersome video switching issues and you'll still need to buy a three channel amp. I think Kal's suggestion of a decent AVR would be your best option as it can handle all of your video/input switching while also giving you the amplification you need. I'd think something like a $200-$300 Yamaha AVR would solve all your problems and sound perfectly fine for movies. Best of luck.
Thanks, Soix but I think I'll be alright. I'll use the Peachtree Nova and Peachtree 220 for the audio inputs that I care about (CD, Apples TV and jukebox) and the B&K for video (TV tuner & DVD player). I think the only issue I'll have is that we'll have to watch movies purchased through Apple TV in stereo only.