Class-D multi-channel amps - cool as a cucumber, but... [Archive] - Audio & Video Forums

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nightflier
06-10-2008, 12:09 PM
I've been using a PS Audio GCA-MC500 multi-channel amp for my HT and absolutely love it. It's on loan from a friend who's testing out another amp, and now he wants it back. :cryin:

Truth be told, while this amp has everything I'm looking for, I simply can't afford it. At $8K (even the GCA-MC100 would to set me back nearly $5K), well that's a down-payment on a car. Not to mention that I've got a perfectly good Outlaw amp sitting in the corner waiting to be put back in service, not to mention an Adcom amp as well. But man there is a huge difference between these and the PS Audio. The other thing that I absolutely love about the PS Audio is that it stays nice and cool even after a full evening of action movies (well it does feel slightly warm, but nothing like the little space heaters the other guys are).

So if PS Audio is not an option, what is left in the class-D category? I'm really not looking forward to going back to a standard amp. There is Bel Canto, of course, but they are also too pricey. I've also considered Channel Islands D-200 monos, but that will also set me back $5K+. Are there any other options?

thedude65
06-10-2008, 02:51 PM
Rotel has the 1077 7ch and 1092 2ch class-D amps i believe for $2499. I think they also have 1ch, 5ch and 6ch, and are all between $2000-$3000.:idea:

blackraven
06-10-2008, 09:31 PM
I still dont understand why Class D amps cost so much. They have less parts and weigh
almost nothing when compared to standard amps. If anything they should be cheaper.

nightflier
06-11-2008, 02:31 PM
Rotel has the 1077 7ch and 1092 2ch class-D amps i believe for $2499. I think they also have 1ch, 5ch and 6ch, and are all between $2000-$3000.:idea:

Yes, but $2500 for 100 watts is a little pricey, don't you think?


I still dont understand why Class D amps cost so much. They have less parts and weigh almost nothing when compared to standard amps. If anything they should be cheaper.

Well I've owned or auditioned many different class-D amps from Spectron, PS Audio, Channel Islands, all the way down to the T-Amp, and while I'm no engineer, I can tell you that the T-Amp isn't at all comparable to the more expensive amps. I'm going to guess that it is difficult to produce an amp that can deliver real power with acceptable performance across the frequency spectrum using class-D technology.

With digital, it's all in the chips rather than some easily traceable analog component or solder point. For example, when you take the cover off a standard amp, you see capacitors, lots of wire going everywhere, heat sinks, etc. But when I open up my Spectron amp, I see three brass boxes that completely encase three circuit boards with computer-like cables and lots of computer chips on them. Aside from a few wires and a transformer, that's pretty much it - it's plug & pray, just like a PC. So when something goes wrong (like in my case), where do I begin to trace down the problem? You need an engineering degree as well as a computer degree to figure it out.

But I think the real issue for the high-end class-D amp manufacturers is producing a unit that can perform as good as solid state and tube amps to be able to compete at that price point. Spectron, for example, has what I consider to be stellar amps, but they aren't cheap. In talking with the engineers, they measure their amps against those from Pass, Krell, and other manufacturers which typically sell for 2-3x as much - so they consider their amps screaming bargains. But for many people the sound of a class-D amp is not organic enough and seems mechanical, so the manufacturers spend a lot of time tweaking the amps to comply with what the industry has determined amps should sound like (I'm infusing this with a little of my own bias, here).

Again, this is all speculation on my part, of course, and I doubt Paul at PS Audio will admit to that. But I can tell you that digital amps sound decidedly different from solid state and tube amps (I've only heard a few tube amps, so I can't speak with authority there). To me, digital amps are not only to my liking, but they also meet another criteria for me and that is that they run cool and thus waste less energy. This gives my green conscience some levity at a time when energy prices are going through the roof. And this is the reason I started this discussion.

musicman1999
06-11-2008, 04:17 PM
Watts are best judged by quality not quantity, $2500 for 100 high quality watts is cheap, for 100 receiver quality watts thats expensive.
Bear in mind that the d in class-d does not stand for digital but is just the next letter after class a,b,and c.

bill

nightflier
06-15-2008, 08:01 PM
Bear in mind that the d in class-d does not stand for digital but is just the next letter after class a,b,and c.

I meant Class-D. With all the computer chips in these amps, it gets a little confusing....

Feanor
06-16-2008, 05:16 AM
Yes, but $2500 for 100 watts is a little pricey, don't you think?

....
The Emotiva LPA-1 (http://www.emotiva.com/lpa1.html) is only 500 bucks; 6x125wpc. Or there's the MPS-2 (http://www.emotiva.com/mps2.html), 7x 200w, fully discrete circuitry for $1700.

If you want "organic" sound you'll have to go to tube, class-A (or high-bias/low-feedback) designs. These are big, produce a lot of heatm, and are relatively expensive. For me budget and those other factors would win out for digital for a mainly HT application

nightflier
06-16-2008, 02:01 PM
Feanor, Emotiva has definitely made it's appeance on my horizon, but what of the heat? Do their amps get very hot after a couple of action flics?

Feanor
06-16-2008, 05:48 PM
Feanor, Emotiva has definitely made it's appeance on my horizon, but what of the heat? Do their amps get very hot after a couple of action flics?

The Emotivas aren't digital :o so I suppose they might get a mite warm.

Rich-n-Texas
06-16-2008, 07:01 PM
Feanor, Emotiva has definitely made it's appeance on my horizon, but what of the heat? Do their amps get very hot after a couple of action flics?
Uhhhh... no!. This has been covered in my and Kex's threads in the Home Theater forum nightflier. I thought you were aware of these.

nightflier
06-18-2008, 11:18 AM
Uhhhh... no!. This has been covered in my and Kex's threads in the Home Theater forum nightflier. I thought you were aware of these.

Do you have a link?

Rich-n-Texas
06-18-2008, 11:26 AM
Newest to oldest:

http://forums.audioreview.com/showthread.php?t=27279

http://forums.audioreview.com/showthread.php?t=27311

http://forums.audioreview.com/showthread.php?t=27087

http://forums.audioreview.com/showthread.php?t=26897

Edit: The last two mention the heat output of this amp.