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Could Class D really be that good?

I've heard statements praising modern class D amplifiers all the time but was sort of hesitant to try. Lately, one particular model caught my eye, the Fosi V3, which costs sub $100 but is praised for having refined sound like class A/B. To fulfill my curiosity, I quickly ordered one and tried it with my Burchardt S400II and Wharfedale Linton speakers. Basically, this is a neutral sounding amp but, to my surprise, the sound is clean, open, airy, with full mids, wide soundstage, good imaging/separation, with nearly null traces of the edginess, dryness, or lean sound that traditional class D amplifiers have. The background is just as quiet as my current systems. The core is the TPA 3255 chip from TI and comes with a 32v, 5A power block, which is supposed to deliver approximately 65 watts per channel (into 8 ohms). It drives the S400II/Linton without any hesitation, as well as my 130-watt-per-channel high-current Parasound A23. Very impressive.

Measurement is not everything. However, according to the lab test results, when operated under 10-60 watts, the distortion level (THD) is below 0.003%, better than a lot of high-end (price) gears. I am going to build around it for my fourth system with upgraded op-amp and LPS. I believe it will outperform my current mid-end (price) amplifiers.

I know, I know, quite a few Audiogoners' systems are above $100k, and mentioning this kind of little giant that costs a fraction could be rather embarrassing. But I thought this is just like gold digging with a lot of surprises and fun. Don't you think?

lanx0003

Showing 3 responses by asctim

asctim
445 posts
 

@ricevs

The measurements don’t change but anyone can hear a difference? This is a huge discovery, and understanding what is going on will advance science. If you can figure out a way to show what it is we are hearing with some new measurement your name will go down in history. Heck, if you can even demonstrate that people are hearing a difference in well conducted tests, and nobody can measure a difference, that alone will get you in the history books. We’ll have a huge scientific mystery to look in to.

You’ve got to do it man, for the sake of scientific progress! If you get good data out there, even the most resistant, hardened skeptics will have to relent. In time, they'll thank you for it.

asctim
445 posts
 

@ricevs 

I assure you, it will be counted as a discovery with your name on it if you'll just demonstrate this phenomenon. The science of audio and human hearing will be moved forward, and the big blob of love that we are will grow more lovingly. 

 

asctim
445 posts
 

I don’t know how to get those results that will put my name in lights. If I did, I’d do it. The method is easy, just do double blind tests on signals that measure identically and show that people are statistically identifying them correctly as different. The method is easy. Getting the result is the hard part.

As for op-amps, if you just swap different op-amps in and out of a circuit, it is not too unlikely that significant changes might occur that can be audible - and measurable. Op-amps need to be in a circuit designed for them to be transparent. So yes, it is generally agreed that if you want to tweak the sound, you have a good chance of doing so by randomly popping new op-amps into a circuit without adjusting the circuit accordingly. You may hear something you really like!

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