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 - 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. |
The basic principle of classification still defines the efficiency, cost, and form factor of a power amplifier essentially. How the audio industry implements technology on top of and around this principle to make them perform well sonically in measurements and actual listening experience is still a ongoing progress, not a cliche understatement you were making at all. See below how the forthcoming Fosi V3 Mono (priced at $280/pair) bridges the gap nicely with the noise/distortion level of the state-of-the-art Benchmark AHB2 that costs $3,500. (from Amirm @ASR, April 2024)
Thank you for pointing me to ASR, where I found these charts that Amirm nicely made. I see that at the maximum power rating of 32 volts SMPS, the 48 volts SMPS does not have a few dB noise advantage. And the 48 volts block gives more headroom/current to serve the peak loads as well when called for. However, at my usual listening level, I don't crank the volume knob to acquire that much power, and I am craving for more clean power from LPS. Also, the op-amp rolling will potentially render sonic improvement just like tube rolling on the tube amp. We will see.
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Try a Douk E6 in front of it with the upgrade that is referred to in certain posts. I do think the Budget Class D and Budget DHT Pre will find a very pleasing synergy. I put a few friends onto the E6, and one is after a period of trial, now seriously considering it for being a replacement for their Django TVC. This was unexpected, as I thought of the E6 as a very affordable dipping of ones toes into a DHT type Pre Amp. The E6 was only presented to the group of friends, as another friend in the group, who is a very competent EE, has investigated quite a few £000's in another UK based EE's DHT Pre Amp Design, that was getting good appraisals during the Honeymoon Period of its use. Not heard the DHT yet in any of the types now available, but do know the report on the UK based EE's design has claimed it has transformed SS Power Amp's relegated from the Top of the Listing for their favour to a whole new level of presentation that are very attractive when experienced. |
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I have been using the LSA Warp 1 Class D in my system since last September. The Warp 1 also uses the Texas Instruments TPA3255 “Purepath” Class D circuit. I replaced my second Willsenton R8 with the LSA Warp 1. I was using the Warp 1 to drive a completely refurbished Audible Illusions Modulus 3 A pre-amp into my Tekton Lore Be speakers. That sounded very good to my ears. I recently purchased the Eversolo DMP-A8 pre-amp streamer and for curiosity's sake, removed my Modulus pre from the chain. I moved to balanced interconnects between the DMP-A8 and the Warp 1. WOW...This combination is so quiet. It improved the definition, soundstage, and instrument position in the music without being harsh or fatiguing. I like it better than with the Audible Illusions tubes in my system. I now know the DMP-A8 has a true analog circuit for my vintage Pioneer 707 turntable. I don't have much to compare it too, but it is truly a step up from the AI Modulus I was using. I am totally impressed with the LSA Warp 1 / Eversolo DMP-A8 combination. Here is a link which describes the Warp 1 circuitry in detail. Of course, your milage my vary.
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@thecarpathian : $149 with the 48 volt power supply. Yes, it is built with good parts. |
<< sigh>> We really need to move beyond amplifier "class" as meaningful. There are a number of "old" Class-D designs I like much better than some megabuck class-A designs. The old cliche's about Class D performance have been buried, and some Class A cliches need to be buried as well. Buy based on personal experience and taste, not amplifier class. |
I have one in my desktop system and will use it as a spare on my bigger systems as well if ever needed. I have another older Fosi amp in a small system that drives kef ls50s no problem. Many “audiophile” amps especially higher output impedance tube amps will fail miserably with ls50s.
A lot of bang for the buck (practically nothing by audiophile standards) and as compact as can be. Try it. You may like it. Little to lose. Makes a great spare at minimum. |
