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 Yes, I am hoping to make that cut as well. I have a feeling first 200 will go FAST. I plan to get a pair without power supplies as I already have a pair of 48V/10A units that I currently use with my ZA3s. Once the V3 Monos arrive, I’ll roll over the op-amps to the new V3 Monos, put the stock op-amps back into the ZA3s and then sell them with the 48V/5A power supplies I have sitting around. -Ed |
@eddnog I am a bit lenient. Could always wait until June from Amazon. I plan to use a 48v/10a psu to power them with a splitter cable, primarily to save space. Do you think will that compromise SQ in any way? |
@pindac , What is the name of the amp you're referring to? |
@lanx0003 I am not sure if it will be detrimental to performance, and I imagine a lot of factors come into play (efficiency/sensitivity of your speakers, listening volume level, driving impedance/load of the speakers, etc.). I didn’t see any results from anywhere testing the V3 Mono specifically with a 5A power supply versus a 10A, making it even more difficult to say. -Ed |
@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.
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