Dennis, if you examine the published sources which actually lab test receivers(e.g., Sound&Vision)you'll note that the noise levels found(more than 70dB down)are close enough to or actually at the theoretical limit as to be totally inaudible in normal use.

As Alan suggested, any advantage some separate preamps may have over some receivers involving a dB or two lower noise floor won't be audible. Engineers have learned how to design receivers combining excellent performance with moderate cost and they're in most cases the sensible cost-effective purchase.

Oops, I didn't clarify my comment about hearing the difference between pre/pro vs. AVR. For me, the decision is more about the power from the amplifiers. My media room will be about 3500 cu ft and used for approximately 50% movies and 40% gaming. So, I figure my amplifier will need to be able to pump out a fair amount of power (at least briefly for particularly loud effects). Somehow, 100 W per channel sounds like a nice comforting number for me (I realize there's no particular rationale behind my choosing that number), so I'd like a system that could do that for at least the front 3 channels. I'm not sure that most AVR's will be able to drive 100 WPC x3 simultaneously(ignoring the lesser power draw for the surround channels). Well, the high-end AVR's may be able to, but their price tags puts them in the range of separates anyways. Most consumer AVR's (< $1000-$1500) would need a separate amplifier to put out that much power, so I'm back to considering separates.

Currently, I'm considering using a $400-$500 AVR as a pre/pro and pairing it with a $500 Emotiva LPA-1 (125 WPC x7, all channels driven). My main concern about the AVR is that the amplifier section will be drawing some power, which will run up the electricity bill and generate more heat. Unfortunately, I can't find a pre/pro that has lip sync/audio delay without costing substantially more than the AVR's that have this feature.

you should check out the outlaw 1070 I am very happy with mine

Dennis, your requirements seem quite modest and realistic and would certainly not indicate a "high-end" (i.e., high-priced)receiver. Three available for around $400, at the beginning of your budget range, would be the Onkyo 604, Pioneer 1016 and Yamaha 659.

One of the other things I have noticed over the years is that receivers tend to have more controls/features than the separates.

I've also seen several conversations that indicate separate amps "really open up the speakers", whatever that means. Discussions in forums with recievers vs. separates usually devolve into each side defending their position too fervently.

I've had the opportunity to to hear separates and a receiver using the same set of speakers and I can't tell the difference (although I am sure that the separate amp really opened up the speakers )

See if you can find a mid/high end store and demo a receiver vs separates. At the end of the day, your ears, combined with the itch to get some equipment you think you want and a generous helping of how much you are willing to spend is the recipe you'll mix. The fun is in the hunt!!

dennisdxl,

Using a separate multichannel power amp with your AV receiver as a pre-pro is an excellent solution. The residual power drain of the unused amplifier sections would be minimal. Even if you went with a separate pre-pro, it would still have a power supply section that consumes AC for the preamp/processor circuitry.

Use your AV receiver's internal amplifiers for all the surround channels and a separate 3-channel power amp for the fronts.

This is probably a dead thread at this point, but I'll add my input anyway.

Quality of receivers vary greatly. On this front, you really tend to get what you pay for. In many cases - particularly in the case of most Japanese receivers - manufacturer specs on amplifier power are very optimistic. Normally, they are rated with two channels driven (at 1KHz, no less, rather than full bandwidth), and produce far less output if all channels need power at the same time. Also, putting what amounts to three components (tuner, pre-amp/processor, amplifiers) in one chassis forces certain compromises that can and do impact performance (some of which have already been nicely explained by Alan, so I won't repeat). Separates, at last higher end ones, generally use superior internal components as well.

From a practical standpoint, there are other things to consider besides potential performance compromises, like upgradability. If you have separates, you can upgrade any part of the equation, keeping the rest of the components. If you have a receiver, you generally will have to replace the entire unit on each upgrade cycle. And with many separate pre-amp/processors, you can upgrade it via firmware instead of new hardware, assuming no extra physical requirements are needed. [While some receivers allow for this, you will pay a premium for this capability.]

From a sound perspective, I have directly compared a high-quality receiver with high-quality separates. The comparison in question is a Arcam AVR300 receiver vs. Arcam separates (AV9/P7) over Thiel CS1.6 speakers. While I was expecting a difference, I was floored by how clear of a difference there was (yes, they were level-matched prior to listening tests). The separates outperformed the receiver by a noticable margin in every category I can think of. Sure, the separates cost twice as much (or a bit more), but the performance increase is well worth it if you can afford part with the extra bit of cash.