Class-D or switching amps, any opinions on??


Does anybody have experience on Class-d or switching amps vs either a/b or traditional amps?? I have heard people knock them for limited ability at the low frequencies. However, I listened to a Linn amp not long ago and could not hear it wanting for anything. I want to hear a Rotel switching amp to compare. Why buy a massive 90lb amp thats a space heater if you dont have to, right???
128x128bobrock
Well, I did mention "though, they are different beasts". We all know that class A is the cleanest amplification technology. But that doesnt necessarily mean anything in our world I venture to say.
As I said before I wad impressed with Linn, but Linn Does not come cheap. I want to hear cheaper alternatives to compare.

Funny, Linn refuses to even call it class-d.
I'd also look at Rowland and Bel Canto's latest. I had the older Bel Canto 1000's for a while and they were very enjoyable, though I prefer other topologies ultimately. I'd have to agree with Bill's general sentiment in pointing out the Class D really does nothing to help people learn to read by associating sounds with certain letters or groups of letters. Neither does class A for that matter. I also do not think class D amps that I've heard sound much like Class A amps. Class D sound has a certain coolness...squeeky clean and buck naked. Class A seems to come at you with more tenacity. If it were a meal it would stick to your ribs in a satisfying kind of way, whereas class D would be Sushi (which I love, btw)...both are enjoyable, but in different ways. You'll get all sorts of opinions as to which does better justice in creating an illusion that there's a musical performance going on in your home. There's certainly a stigma attached to new technologies in this hobby...just as there was when transistors were introduced as the "superior" antidote for tubes, or when CD's were introduced and gradually took shelf space away from LP's in most stores and homes. That's making no judgments regarding which of those technologies are actually better (I have an opinion but it's beside the point). Definitely listen with your own ears and make those decisions yourself, but I'm very confident in my statement regarding phonics.
Magfan - I don't know if Mosfet configuration alone can be considered topology. Icepower uses full bridge vs. half-bridge on Hypex. Some people claim that full bridge sounds more "tube like" but also places half of the supply voltage on speaker terminals and in addition cannot be bridged.

Bobrock - Bass is one of the stronger points of class D. The issue is not if class D is best sounding but how does it sound for the money and if YOU like it. If there would be something really wrong with it (as Audiofeil implies) Jeff Rowland would not switch whole production to Icepower. Class D sound is very clean and revealing - will show deficiencies in your system.

As for the amp being "switching" or using switching power supply - every linear supply is in fact switching supply operating at 120Hz.

Main problem of class A/B is very high gain before feedback (up to 4000) that is about 10x higher than gain in class A amp (as low as 200). This high gain, in presence of limited bandwidth, is causing some overshooting on high slew rate pulses (TIM distortion). As a result of this amp produces/enhances higher order odd harmonics - that our ears are very sensitive to, making sound sharp/unpleasant. Tube amps on the other hand enhance even harmonics making sound wonderful on voice or guitar bad worse on instruments with complex harmonic structure like piano (sounds like out-of tune). Class D or A are likely neutral.
Love my Class D Gilmore Raptor monos. Clean and clear, with gobs of power and a sound that is smoother than I could have imagined. 93% efficient as well! They use huge toroidal power transformers and weigh 37lbs each, a lot of weight for class D amps. I've also owned the stereo model, the Raven -it has a similar sound to the raptors, but only half the power.

When I did the audition for the Raven, I compared it to Nuforce ref 9 V2 and an Atmasphere OTL tube amp. The Gilmore sounded more like the Atma than the Nuforce (which was harsh to my ears).

Gilmore Amps