Pre-amp worthwhile?? Denon AVR-4311 with B&W 703's

You will hear an immense, obvious, and very very worthwhile improvement going from your Denon multi-channel receiver to ANY integrated amp. The improvement is so vast you could sell your Denon and with whatever you get buy a new integrated and it will still sound a lot better. 

Don't take my word for it. Go and listen. DYODD!

The reason this works is very simply that when it comes to sound quality, QUALITY is a lot more important than quantity. Receivers try and cram way too much stuff into a box. So many parts the designer is forced to spend pennies on parts that require dollars to sound good. Then even if by some miracle a few good parts get in there they are still all crammed so close together it makes proper isolation impossible. On and on. Its just a mess. 

Buying a pre-amp in your case however would be a mistake. A pre-amp needs an amp. What you want is an integrated, a pre-amp and amp in the same box. A STEREO integrated. Because the exact same logic that applies to the receiver also applies to multi-channel. 

Thank you for your reply, I appreciate the time you have taken. I would like to clarify some of your statements as much of the terminology is unfamiliar to me.

You mention your preference for an 'intergrated amp' over a 'multi-channel amp'. Isn't my Denon AVR-4311 amp an 'integrated, multi-channel amp'? If not what is the difference between the two?

Is your main point that having separates i.e. pre-amp > power amp improves sound quality outcomes, rather than a multi-channel AVR as the addition technical requirement (and associated electronics) cause noise and signal degredation?

@uoaou 

Whenever people said integrated amp we always refer to a stereo integrated amp, not an AVR (AV receiver). Stereo integrated amp = stereo preamp + stereo power amp in a single chassis. Stereo means two-channels.


AVR (AV receiver) = multi-channel AV preamp surround processor + multi-channel power amps all cramped up in a single chassis, like your Denon receiver. And the AV preamp surround processor section contains onboard multi-channel DACs, DSP and other surround processings. Big compromises in audio performance and sound quality with using AV receivers as all the internal noisy components circuitry share same power supply and lack of isolations, etc. Lots of noise and interferences within AV receivers introduced by a lot of different things eg digital video processing circuitry, digital audio processings, DSP, multi-channel DACs, etc. And all these million things share same power supply with its onboard multi-channel amps section, preamp surround processing analog audio stages, etc, etc, etc. 
It's almost impossible to isolate the power supplies and million other individual components circuitry (both digital & analog). Everything are very crowded , jammed up and cramped up together inside the AV receiver. Big mess. That's why the audio performance and sound quality (sonic fidelity) is highly compromised especially when used for stereo music playbacks. 

You stated in your original post that you love listening to high quality stereo music and your Denon receiver is not capable of providing high quality musical sound for your stereo music listening. 
If you value more on your stereo listening to music than home theater (surround movies) I suggest you look for a good quality stereo integrated amp for your stereo music playbacks and keep your Denon AV receiver for 5.1 movies. Look for a stereo integrated amp that has a HT bypass feature or even the ones that do not have a dedicated HT bypass input you can always use any analog audio input on the stereo preamp (usually Aux input) and configure that input as unity gain or fixed gain for HT bypass. And connect the analog preamp output for front LR channels of your Denon receiver to this HT bypass analog input on the stereo preamp. So for stereo music playbacks just use the stereo integrated amp and you don't even have to turn on your Denon receiver. So the stereo power amp section on the stereo integrated amp will drive your main front LR speakers (B&W 703) and your center and surround speakers will still be run off your Denon receiver. And for surround movie playbacks (HT) you will have to use the volume control on your Denon receiver as the volume on the stereo integrated will be disabled (fixed gain) and the power amp section of the stereo integrated amp will still be driving your B&W 703 front LR speakers. 

There are many good choices to look for a stereo integrated amp. The Rotel RA-1592 ($2500) will be a great choice for your B&W 703 as Rotel amp would usually pair really well with B&W. This Rotel RA-1592 has a built-in good sounding DAC so you can connect your digital music file sources to the Rotel using a USB cable to the Rotel's USB DAC input. You can also connect a CD transport using a coax digital cable to the Rotel and utilize the Rotel's DAC for your stereo music playbacks.