I'm currently considering upgrading my Denon 3805 to one of the three receivers named in the subject. The Pioneer is my favourit but is it powerful enough for my Axiom-speakers (VP150, 2*M80, 2*QS8, 2*M2, EP600)? What about the Onkyo? I've heard of quality-problems with Onkyo. Is it better with the 3009-generation?

Any one of them will work for your system, there are many on this forum using those or similar products from those manufacturers. The great part is that if you ever decide you want more power you can add an external amp later on.

Typically when someone want's to upgrade they feel they are missing something with their current setup. If you tell us why you want to upgrade someone can offer some specific advice. How big is your room? If you want the latest features then any one of those listed will fill the bill. If its more power then i would suggest adding a 3 channel amp like the emotiva xpa3. I chose Denon for myself more for the styling than anything,all 3 brands offer similar features,most of which i dont need or use.
I would check the respective threads at avscience to see what actual users are saying . Only the lower end onkyo's seem to have some issues,but im sure they all have problems which go unreported.

It is always important to remember that in the lower end line of the major manufacturers many of them have eliminated the "Pre-Outs" on these particular models, so if you ever wanted to add separate outboard amplification down the road, you are going have to spend more money now anyway to move up to at least the mid-range product if for nothing else, to get this feature.

The OP has an amp that currently has preouts, which is why i was wondering why he wants to upgrade. His current reciever is really not missing anything important from where i stand,other than maybe airplay which i absolutely love having.The Emo 3 is on my radar and i will probly pull the trigger soon before the sale ends.

Mickey, good to hear from you again. The power capabilities of all three units you mention are essentially identical at about 140 watts into 8 ohms(and not appreciably different from your 3805). As to reliability, problems occasionally crop up with all manufacturers, but Onkyo hasn't been unusual in this regard recently and its receivers are comparable to other quality units.

So, in my view neither power nor reliability should be significant determining factors in your decision. Go with the new features that you're looking for at the best price. In particular note that the 4311 and 3009 have the highest grade Audyssey MultEQ XT32 for auto calibration and room equalization, which can make for a significant improvement. My suggestion would be to pick between those two based possibly on other features you want, or the price available to you.

I moved from the Denon 3805 to the 4311 using my M80's based setup. I have a big room, and I liked to have the M80's properly powered, so I ended up adding an XPA-3 to add more juice, not that it really needed it, but the XPA-3 added a little bit extra and I feel that improved the sound of my setup.

I believe that the difference in power between the 3805 and the 4311 to be not that big. I could detect that the 4311 without the outboard amps was more powerful than the 3805, but the difference is not pronounced.

The biggest improvement came from Audyssey MultEQ XT32. Once I completed the Audyssey calibration and when I run the system in Audyssey DSX mode, the sound suddenly opens up and the system sounds incredible. I have not demoed many calibrated systems, but judging by various demo rooms and cinemas ...etc, my system sounds better that everything I heard before. My room is untreated, large, and the shape of the room is awkward.

I would say go with the upgrade, just make sure that the new receiver has Audyssey MultEQ XT32, calibrate and enjoy. I am re-watching movies and re-listening to music because I am hearing details that I have not heard before, it is that good.

I was listening to Pink Floyd's The Wall from the new discovery set a couple of days ago. This is one of my favourit albums, and it is the first time I play the re-engineered CD on the new system. I played it on my NAD CD player with the 4311 in Audyssey DSX Dolby PLII mode. It was incredible and I am very pleased with the sound. It does not get much better than this in this hobby.

Sorry if I seem to excited, because I am, but go for it. You do not know what you are missing.

Agree with JohnK to narrow down your choices to 4311 and 3009. However, there are some differences in these two models.

4311 is using 24-bit/192-kHz AK4358VQ DAC's - 2 per channel differential and 2 x 32-bit processors (ADSP21367 x 1, ADSP21487 x 1). I don't understand what is "2 per channel differential".

3009 is using 6 x 24-bit/192-kHz Burr-Brown DAC's but doesn't specify the processors. However, its predecessor 3008 uses 3 x 32-bit processors (TI x 3). If 3009 continues to use the same DSP, it would be a plus.

DAC and DSP are important in reproducing the sound without distortion. IMO, they are more important than watts. They decide how your system sounds to some extent.

I have an Onkyo 5008 and don't have any quality issues so far. With my Axiom speakers, even my MP3 sounds so incredible, let alone CD.

I would suggest that you write to or call the manufacturer to get to know the exact specifications for the models. Then you can decide which to buy.

I would be willing to bet that most people couldn't tell the difference in a blind listening test of those 2 avr's.

Hmmm... Denon used to run Burr Brown for many years, I wonder why they changed, pricing/licensing I would guess.