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Are Class-D Amps Ready For Prime Time?

Despite their high efficiency and low power consumption and heat generation, class-D amplifiers have long been relegated to second-class status by much of the audio community, appearing mostly in low-cost, low-performance audio products. (One notable exception is powered subwoofers, which require amplification only in a limited frequency range.) Lately, however, full-range class-D amps have gained more respect—for example, Pioneer has been using this technology in several generations of its Elite AVRs, including the 2011 SC-55 and flagship SC-57 reviewed exclusively on

Reviewer and long-time class-D detractor Michael Fremer was finally won over by the new Class D3 amp used in the SC-57 (shown above), but many audiophiles still scoff at this technology, preferring the sound of purely analog class-AB designs. What's your take? Have class-D amps finally achieved a performance level commensurate with class-AB?

Vote to see the results and leave a comment about your choice.

Are Class-D Amps Ready For Prime Time?

Jamhandman's picture

I have the SC-05, which contains an older model of the Class D used in the SC-55, but it sounds great. I don't use it to drive full range speakers, only down to 80Hz, so this may not really be taxing on the system, but I believe this is a real world case for most setups.

On AVSForum, I heard that the x7 Amp (57, 37, 27, 07) does better on the low end.

Stephen Trask's picture

When I first read Michael Fremer's review of the Rotel RMB-1575, I was quite entertained and blown away by how much he disliked that amp. I heard that unit for myself a while later and felt much the same way, although compared favorably to my ears to the comparably priced Integra I was pitting it against. And when I heard Pioneer's SC-37, the last iteration of the Class D, I was even less impressed. But having witnessed the digital revolution in the recording of music, the improvement of DACs, the increase in bit size and samples rates the simulation of amps and tape compression and Fairchilds etc, I am convinced that there is no reason this technology can't develop in quality even to the point where it is arguably better than Class A in some ways. And if Michael Fremer thinks we've begun to reach the point where Class D is a perfectly viable and acceptable alternative to Class AB or A, then I say, yeah, it's arrived. Because boy, he really hated that Rotel.

I should mention that while the Rotel amp is not so great sounding, although still better than the integra, their receivers sound great, especially the lower model. Is Class D better at lower power?

bwilberg266's picture

I have an SC-37 driving Energy RC-50's, an RC-LCR, and two RC-R's in an 800 square foot apartment, so needless to say I have had extensive experience using the Class D amps at low power.

I am running the RC-50's at full range since I feel like having a sub-woofer in a small apartment may get me evicted. I have definitely been pleased with the quality and depth of sound while listening at these lower levels. This past weekend a fellow audiophile friend of mine was over and he stopped himself mid conversation and noted how full and rich the sound was even though the decibel level was so low. He said that he was so impressed that while the music was low enough to carry on a conversation at a comfortable level the dynamics in the music were still very rich and lively.

Since we weren't even discussing audio at the time his comment was made it amazed me all the more that it was so noticeable to him.

Granted this is just one man's opinion, but I am very pleased with what the Class D has done for me in my listening space.

mynamehear's picture

...Or did someone say the No.53 wasn't ready for primetime?