DAC + AMP vs Home Theater Receiver? - AVS Forum
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post #1 of 3 Old 06-10-2007, 02:42 PM - Thread Starter
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Whats the difference between the two? Say for example person A) has a digital receiver like a panasonic XR hooked up to the SPDIF opitcal of a sound card.

Person B) has an analog sound card with replaced Opamps, a $300 DAC, a $700 amp etc. They've spent close to 10x as much vs the spdif out to a digital receiver.

Is the sound difference between to two really that extreme or is it all just a bunch of snake oil? I notice most of these DAC's and amps are DIY kits or boutique items. I've asked around and people generally just seem to give me ad-hominem saying things like "receivers are good for crappy speakers but they're no where close to high end" Can anyone please explain the differences to me?
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post #2 of 3 Old 06-10-2007, 03:29 PM
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Quote:
Originally Posted by ermc View Post

Whats the difference between the two? Say for example person A) has a digital receiver like a panasonic XR hooked up to the SPDIF opitcal of a sound card.

Person B) has an analog sound card with replaced Opamps, a $300 DAC, a $700 amp etc. They've spent close to 10x as much vs the spdif out to a digital receiver.

Um, if you've got an analog card, what are you doing with a DAC?

Quote:


Is the sound difference between to two really that extreme or is it all just a bunch of snake oil?

It's not extreme, that's for sure.

Quote:


I notice most of these DAC's and amps are DIY kits or boutique items. I've asked around and people generally just seem to give me ad-hominem saying things like "receivers are good for crappy speakers but they're no where close to high end" Can anyone please explain the differences to me?

It really all comes down to how much power you need, and that's simply a function of three things, roomsize (seating distance), speaker efficiency, and listenning level.

With most speakers, in most listenning setups, at normal/modest volume, it really only takes a couple Watts (<5 per channel) to hit reasonable levels.

For example, say you've got a 7.1 setup, and you've got nice efficient Klipsch speakers (94dB/W/m), if you're 10 feet from them in a normal room, you only need 10W/ch to hit 105dB, which is reference level for movie soundtracks. If your speakers are a bit less efficient, say 87dB/W/m, you need 50W/ch for the same thing.

Of course, that's reference level, and very loud, I'd say most people listen at less than that, I know I listen at probably 10-15dB below reference level, for that, 95dB, with the above Klipsch's, you only need 1W/ch.

http://www.myhometheater.homestead.c...alculator.html

Of course there are pathological examples of systems that really do need huge amps, for example if you were running Magnepans, you'd really need 200W/ch to hit reference level.

There really isn't anything in audio reproduction that's "magic", the science is very well understood. Articles have shown that provided amps aren't driven into non-linearity they pretty much all sound the same. Of course that caveat is the point on which disagreements arise.

Some receivers, especially the low-end ones at the big box stores fall far short of their rated specs, sometimes they're referred to as rated ISBL*. So if you go to a big-box store, and get a cheap-ish "100W/ch" receiver, some average 85dB/W/m speakers, it's entirely conceivable that the system, once set up, would be unable to deliver cleanly the output you want. Maybe that receiver can only do 10W/ch real content going to all channels, such a setup might "run out of gas."

But once you get up into the mid-fi systems (Pioneer Elite, Denon, Onkyo, etc.), the odds of them being far over rated drop.

But it really all needs to be put in perspective, any difference achieved at the electronics level (assuming you're electronics are sufficient, ie not clipping), is going to be in the noise. The biggest contributor to overall sound is the room, by far. Followed by the speakers.

You'd be much better off dumping $1000 into room treatments, or even $0 into some effort to ensure your seating is optimally located, than to spend it on electronics.

FWIW, I went down the "HiFi" path, when I graduated from College and got my "real" job, almost the first thing I did was go out and buy and Anthem AVM20 and an MCA-50, both very well regarded "high-end" (though not uber-high-end) products to replace my modes Yamaha RX-V595A receiver. And since then I've been through several amps, from the lowly Sonic Impact T-Amp, to the MCA-50, to Crown XLS 604s (380W/ch pro amp), to an Outlaw 7125.

And through all that, I can't say anything changed the sound one way or another. Yup, even the T-Amp didn't sound fatigued (due to my really efficient Klipsch speakers). So in the end, I'm not going to say that having gone down this path, I regret it, I really love my AVM20, but not because it's a sonic revelation, I love it because of it's features and user interface.

However, if I were to start over today, I definitely wouldn't bother going down that road, I'd go with a nice mid-fi receiver like a Pioneer Elite, in fact given the costs involved, I'm seriously considering replacing my Anthem/Outlaw with an 84TXSi.

See what an anamorphoscopic lens can do, see movies the way they were meant to be seen
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post #3 of 3 Old 06-10-2007, 04:29 PM - Thread Starter
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Appreciate the response.
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