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?

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@pennfootball71 Have you heard any of the Aavik amplifiers?  Word on the street is they are true A/B killers.  Aavik is one of the brands within Denmark Audio Group, Borressen Speakers and Ansuz cables being the other two.  

I have heard Active Driven OB's with a configuration for Amplification with similarities to the method suggested by yourself.

The OB's although with 4 Drivers and a Amp for each Driver with Class D for the Lower Frequencies, has been the best Speaker Array heard in a unusual venue.

I would strongly suspect if heard in the home set up, they may be the best Speakers experienced over multiple years.

I made it known recently, that very recently, a friend who is a EE, has bought into a DHT Pre Amp Design, and in using this with a Neurochrome Amp, it has blown them away with what is on offer. I am yet to receive an Demo', but some of the Local HiFi Group have, and they are thoroughly impressed with the experience had.

I myself am still remaining thoroughly impressed with the Pass Korg B1 design for a DHT Pre Amp, especially after it has a few well known circuit mod's added.   

I could not agree more, @pindac. Such a ’bybrid’ amplification could be even better on a active crossover system. A good (mini)DSP could easily lead us there, which will be more convenient than the passive crossover system. A lot of class A / tube amp or these class D module amp do not even have ’pre-out’ or ’line-out’ any more for bi-amping.

@audiophil88 I have heard the Aavik D it is good on Borreson but if you look on the Aavik website their flagship amps are pure class A. Why do you think that is?