Separate Amp for AV receiver

What are you not happy with? If you love the sound quality but it doesn’t have enough oomph then maybe an external amp... but cheap anything usually doesn’t sound good. If the overall sound quality is not good... then most likely it is not going to be any better... and quit possibly worst..

i’d trade in for a NAD or some other high quality mid-FI solution.

Not happy with the sound from a receiver. What are the odds? That’s a joke son, there are no receivers that sound good. Most important lesson to learn from this is why: because they try and cram way too much stuff in way too small a package for way too little money.

Audiophiles love to overcomplicate everything but the fact of the matter is high end audio is very, very simple: high sound quality comes directly from high quality parts.

Yes it really is that simple. Works right down to the smallest detail, where each and every little part- each capacitor, diode, resistor, transformer, etc - the quality of each of those directly impacts the sound quality you get.

Not watts. Not frequency response. Not any of the other BS. It is all BS. Parts quality, that is where its at.

So now, what are the odds you are gonna get good sound quality from a cheap nine channel amp? Slim to none? Or just plain zero?  

Study the above information very carefully. It is written with wit and style but every word of it is true. So now, repeat after me: On second thought I do not want multichannel. I want a good stereo integrated amp.

Excellent.

What is the amp?  I mean if it is an old Krell or Bryston that the OP is calling cheap, it might make a difference.  The ultimate question here is the separation of pre amp and power amp.  For the sake of argument let’s say we are in the 2 channel world.  Someone has a cheap pre and a super duper power power amp.  Now in theory all that the pre is supposed to do is pass the signal unchanged from the source to the power amp, and the character of the latter will determine the sound.  In practice, we know that the pre matters very much, and most of us budget roughly equivalent for pre and pro.
  I would argue that the pre is even more important in multichannel, because the challenge of reproducing a realistic—as opposed to gimmicky—soundstage in multichannel.  So to cut to the OP specific question, and having actually owned that Denon for a brief time, I wouldn’t bother.  It will be the lipstick on the pig phenomenon.  The Denon is dry, desiccated, and it could be exhibit A in support of Millercarbon’s post.  No power amp will fix what is wrong with it.
  I disagree with MC in that while separates are to be preferred, it is possible to get pretty good sound from a receiver.  Good room correction helps, and again I think RC is more important in multichannel because some of those surround speakers can blow up a soundstage unless they are properly controlled 

@millercarbon summarized it succinctly …. Point, set, and match in tennis match jargon.

Everything in this hobby is built to its price point, without prejudice to AVR’s suffering material audio compromises as primarily video gear with everything complimentary being stuffed into a limited space unibox. . The mass-market AVR’s have limited power supplies as a major culprit.

The DENON AVR-X4300H is (was - now discontinued…) only an upper-mid range AVR with an RRP of $2,999. It was never designed nor built to perform at Hi-Fi strata audio performance .

I concur with all the prior posts that AVR’s comparatively suffer in audio performance. Adding an external power amp now still won’t compensate for its inherent design and build limitations.