2. amps-preamps
  3. 189470-161121

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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pindac's avatar
pindac
2,417 posts
 

@thecarpathian To acquire an answer to this inquiry, will take a little time as I am out of touch with the person who presented the Power Amp.

Plan B, I have trawled the mails of the Amp owner on their preferred forum, I am 99% sure the Link in the follow up post is the Amp I was able to be demo’d. ( I'll Post Link separately incase this post gets dumped if the link is refused). 

What I do know is the Amp’s were a Punt Purchase by an individual who is a adept EE and has a lot of DIY Builds under their belt. Also the Amp was purchased to be part of OB Speaker DSP Amp assembly.

The Amp was in the owners view so impressive for the outlay, the owner wanted it to be experienced as a Monoblock for the entirety of the Frequency Range.

I also know the Amp’s in question had a couple of changes to the original schematic/topology, as a few components were swapped for parts the Amp’s owner had in their spare parts collection. I recollect talk of a change in the Power Supply Module. I also know through the discussion had, that the changes were not expensive or complex and thought of as quite simplistic.

Whilst Trawling the Amp Owners mails, I have learned the Owner is now a vociferous advocate of the Neurochrome 686 Power Amp’s, I my self can not disagree, I have very positive indelible memories from all experiences had, where these Amp designs are used.

The Amp Owner makes the statement ’World Class for Extremely Sensible Monies’. To make such a statement is of interest, as one very good friend of this person, is the owner of LDA who does make World Class Amplification.

 

 

pindac's avatar
pindac
2,417 posts
 

 

thecarpathian
4,169 posts
 

@pindac ,

That's terrific!

Thank you for taking the time to search this up.

pindac's avatar
pindac
2,417 posts
 

The first time I read the asr Link is today in the last few minutes, I am glad my description of listening to this Amp design, supplied Signal from a Vinyl Source and Soulution Pre Amp', seemingly suggests the measured performance is able to produce sound that is quite attractive to some individuals preferences for a produced sound.

Some of the Neurochrome owners I know, and have been instrumental in their becoming users of Neurochrome designs are now, seriously investigating (actually building) up to date designs from Purifi, which is the evolved design from Bruno Putzey. 

edavis's avatar
edavis
20 posts
 

I had a Krell FPB 200:amp, with a Pass Labs Aleph P preamp driving a pair of Martin Logan ReQuest speakers, and a dealer talked me into trying a Peachtree Nova 220:se to replace my Krell am and Pass preamp. I was totally amazed at the sound quality and performance of the Peachtree integrated amp, which was a class d amp. I let my ears make the decision……I sold the Krell amp, and Pass Aleph P preamp and used the Peachtree from then on out. The Krell and Pass systems were both Stereophile grade A systems.

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