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

@lanx0003 - Thanks for responding to a point I was not making.

I was trying to say that the subjective "sound quality" cliches that were made in the 1990's about Class D amps no longer apply today.  All the measurements you point out may be accurate but tell us little about how well a class of amplifier today may actually sound vs. another. 

@erik_squires I went back to you post (pls do the same) and found no mention of "sound quality" and "1990" How is one supposed to know what you were "trying" to say big shot. BTW, it is not an accurate statement that, back in 1990, the class D with PWM has already sound comparably well with sinusoidal sound wave.

Class D, class A, class W...

Don’t care. That this is class D is of no relevance to me. What is relevant is if it sounds that good for that little lay out, I’m grabbing one just for the fun of it!

Might as well grab the preamp at $79 while I’m at it.

That’s still less than the cost of a nice dinner out.

you should listen to the electronics from audio group Denmark their class d is phenomenal sounding haven't heard it in person but even online it sounds fantastic you can get a full system from there with their entry level stuff for between 30 and 50,000 I've heard the 50,000 and the $30,000 systems and they sound incredible especially for that money.

I won a V3 in a YouTube contest. Already had a cheap Fosi integrated amp, the TB10D driving some desktop PC speakers (repurposed crappy Polks suitable for PC audio) so I sold the TB10D to a coworker. Ended up getting the matching "tube input stage" P3 preamp. Think the combination is not as detailed as feeding the V3 directly, but it sounds nice.

I would simply say these cheap devices do their jobs but are not "giant killers". I’ve read where they have some issue with not controlling bass very well, especially on 4 Ohm speakers, but what can you expect for ~$100?

The TI 3255 chip in question is OK, but you can’t really compare it to a GREAT implementation of Class-D using Purifi, icePower, or Hypex chips (for a lot more money).

But hey, if these cheap Chi-Fi devices get someone started in audio, then good.

For desktop use (or in a garage or outbuilding) they serve a good purpose, but if I were putting together a low-cost "system", I’d look at cheap integrated receivers by Yamaha or Sony that offer a lot more connectivity, one even a phono stage, and legitimate remotes. Those can often be found for well under $200.