Oh Krell, my Krell

[Jack in Wilmington]

““…previously” might be the key Word here. Class D has evolved. Once it was only good for subwoofers. I am not a circuit design guru but higher switching frequencies may have helped a lot.______“A lot of times, people don't know what they want until you show it to them.” – Steve Jobs______A lot of people aren’t aware of the virtues of class A. But they do have their drawbacks. People believe class D is just not good enough…So manufacturers shovel class AB through consumers’ throats. Because it is practical to design and sell class AB.I had been blessed/cursed with a pair of Yamaha NS1000M speakers. Like my AKG K701 headphones they let you hear tiniest amount of defect in the source. For me they are the best speakers in the world regardless of price. For those of you not familiar with these speakers here is a short glimpse: Yamaha NS-1000M | I have used several class AB amplifiers to drive the Yamaha NS1000Ms with disastrous results. Midrange and highs were much too bright and hard, too little bass. I decided to build a solid state class A power amplifier to drive it. Postimage.org / Pure Class A Power Amplifier II Result was unbelievable. Midrange and highs are now transparent as pure water and bass is deep with great authority (although power is only a 2x30W./that'a 500W torodidal power transformer inside).Later when it was time to replace my AV receiver I looked at the top of the line Pioneer receivers, I was disappointed to see that all of their higher models were class D. I didn’t think fondly of class D at the time. Well I bought Pioneer SC-LX87 anyway. When I hooked it up, WOW! Its sound is almost close to the class A power amplifier! Class A amplifier on steroids!The truth is Class AB is practical for the industry to build and the consumer to buy. Both the industry and the consumer is happy. I don’t know why Stereophile or other publications investigate the matter. Though they do their listening evaluation I think one problem lies with the labs measuring THD and IM while the amplifier is connected to purely resistive 8 ohm dummy loads. The general public starts to think their amplifier is totally distortion free, while class B/AB crossover distortion grind their ears.

I just know that I've had 2 class D amps in my system, a tube amp and a solid state and neither could drive my speakers like my Pass Labs amp can drive them. The class D's just seem to fall apart when the music got complex and didn't take the highs to their apex and instead rolled them off. If you're right I'd expect to see some class D amps rated in the Class "A" or even "B" when Stereophile does their annual best of the best article. I'll look for that this year when the article hits the news stand. I'll also read closely the articles on class D amps and see if they mention being better now than class AB.

[Kursun]

If you have a Pass Labs amplifier, anything by Nelson Pass, I frankly think you don't need to look any further.

[Jack in Wilmington]

If you have a Pass Labs amplifier, anything by Nelson Pass, I frankly think you don't need to look any further.

I agree, I didn't feel like I had to, but then you got me thinking that maybe I missed something in my two class D amps. Maybe with a speaker that is an easier load like an 8 ohm 90 sensitivity speaker.