Question about Sunfire amp vs. Sherbourn and Emotiva

[KevinF]

I believe all of these amps are said to be cool running amps that produce little heat unless driven hard.

My question is does the sound quality of a Sunfire really compete with the other two? I noticed that the Sunfire 7 channel/400 watts per channel amp was only 52 pounds shipped. I assume the 200W per channel is even lighter. Is there a reason it is so light in comparison to the Emo and Sherbourn 2100, both of which are only 200 watts x 7 but are well over 100 pounds each? Does it have the same current capacity at low impedences? I realize it is costlier, so they may account for some of it, but it seems surprising.

 

[gene]

The Sunfire amp uses a track down converter and Class H topology to increase efficiency. It also uses a common power supply as opposed to individual supplies for each channel like the Sherbourn and EMO. This explains much of the weight differences.

Despite what the literature claims,

400 watts rms continuous per channel, all channels driven into eight ohms from 20Hz to 20kHz with no more than 0.5% T.H.D.

the amp cannot drive 400wpc continuously with all channels driven, not that this is a real world scenario to begin with.

If you look at their literature, their amp is fuse limited to 1800watts which is basically 120Vrms x 15A, their best case amp efficiency for Class H (assuming negligable transformer losses and near unity power factor - very unlikely) is about 60%. Thus best case scenario, assuming you hold the line voltage constant with a VARIAC (another unrealistic scenario), you can deliver a whopping total of 1800*.6 = 1080 watts to the speakers. Divide that up to 7 channels and you get about 155wpc NOT 400wpc!

 

[KevinF]

Thanks. One follow up.

The Sunfire amp uses a track down converter and Class H topology to increase efficiency. !

Oh. Yeah, that's what I was gonna say.

Despite what the literature claims, the amp cannot drive 400wpc continuously with all channels driven, not that this is a real world scenario to begin with. . . . Divide that up to 7 channels and you get about 155wpc NOT 400wpc!

Ok, that part I can understand.

Also, I just found this quote in a post from a Sunfire owner over on AV123: "In Sunfire's application of Class H they eliminate most of the heat sinking because it's not needed; Emo not only includes heat sinking but fans as well, and I just wondered why that was, since they both use variable rail volatages."

So maybe that accounts for some of it, but probably most is the power supply, I guess.

Anyway, suppose I put aside their shameless puffery regarding the all channels driven spec. Recognizing that I will never actually even listen at 7x200, let alone 7x400, will it still not sound as good at reasonable listening levels? I would guess only the 2 fronts and the center will ever be driven to any substantial continuous volume. The smaller size is very appealing, but I don't want to give up any sonic quality, especially since it's pricier.

 

[newfmp3]

maybe they just realize that some people actually just buy into this whole weight thing, and just line their amps with lead.

 

[Khellandros66]

Honestly Carver is like Bose, they lie and and use twisted marketing techniques to win over buyers. Sadly I have heard their subwoofers too and its so ONE NOTE its lame, my $350 Yamah does better musically.. granted its not as loud.

~Bob