Back in February I first posed the question, "Do separate components sound better than AV receivers?" when I checked out the Outlaw Audio 975 surround processor and 7125 power amp and compared their sound with a Denon AVR-1912 AV receiver. The Outlaws handily trumped the receiver.
I ran another comparison with the Denon, this time with the Emotiva UMC-200 seven-channel surround processor ($599) and UPA-500 five-channel amplifier ($399). If you just go by the numbers, the AVR-1912's 90 watts per channel might appear to be slightly ahead of the Emotiva UPA-500 amp, which has 80 watts per channel. Oh, but the UPA-500, like most high-end amps, delivers considerably more power into lower impedances, and in this case the UPA-500 can muster 120 watts per channel into 4-ohm loads.
It's worth noting at this point that speaker impedance doesn't remain constant; an 8-ohm-rated speaker may average 8 ohms, but when reproducing bass it might drop down to 3 ohms or less, and at other frequencies it might go up to 10 or more ohms. So in other words most speakers' impedance specifications, take 8 ohms for example, don't convey the complexity of the speaker's true impedance when playing music or movies. Maybe that's why high-current amps like the UPA-500 sound better than most receivers, because very, very few receivers can comfortably drive 4-ohm loads. Few receivers are big enough to house the parts required to generate the current needed for 4-ohm loads. Even Denon's $2,499 AVR-4520CI receiver doesn't have a 4-ohm power rating, but the Emotiva UPA-500 does (it's 120 watts per channel, with all channels driven).
I listened to the Denon AVR-1912 and Emotiva surround processor and amp with the Pioneer SP-PK52 speaker system, paired with a Hsu Research VTF-1 Mk2 subwoofer. The Denon sounded excellent, that's why I've used it as one of my reference receivers for the last two years, but the UMC-200 and UPA-500 took the sound to another level. So much so I turned off the Hsu sub for some of my listening tests, and the Pioneer towers sounded remarkably powerful on their own.
This isn't really just a story about what's more powerful; the real question is, do "separates" sound better than receivers? I'd say they do. The Emotivas delineate dynamic shadings better on my jazz CDs. On drummer Terri Lyne Carrington's "Money Jungle" the interplay of the rhythm section musicians is easier to follow over the Emotivas, and the sound is fuller-bodied and warmer than the Denon receiver. Emotiva's potent duo doesn't play louder than the Denon, but they sound better when played loud. There's less strain when playing movies with violent dynamic jolts, like the amazing train crash scene in "Super 8."
Emotiva has a 30-day, no-questions-asked return policy, so you can listen to the UMC-200 seven-channel surround processor and any of Emotiva's power amps for yourself and see if they sound better than your receiver.