I have bought 5 different TPA3255 amp boards and have built all 5. I upgraded filtering on all of them.... I have found a reasonably small 10mfd cbb cap that I use on the inputs. I always upgrade the filter caps normally 63v caps, sometimes higher, but I switch them to the highest capacitance that I can get to fit. I look at coil quality, occasionally replace those, but not always. Outside of the input, I upgrade electrolytic to mkp/cbb where I can, If not, I upgrade the electrolytic and bypass with good caps (mkp or film & foil) on bottom of the board. Always make sure the 3255 chip is properly mounted and has decent heat distribution. I use 36 to 46v smps supplies that I add significant filtering between supply and board. These amps have ranged anywhere from pretty good to flat out excellent. I have 2 more in my sites. I have enjoyed these amplifiers very much.
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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Bear in mind a fully loaded PCP for a Purifi Design as a DIY Build / Commission Completion can be acquired for between £300 and £600. I would think that if the casing is not OTT on the aesthetic, the end Amp will be close to the £1K pricing for the upper cost model, even with Pure Copper RCA / XLR used and PC Triple C used as Hook Up wiring. When assembled in a Casing there is little to compete, unless another wad of £0000's is spent. I have also made known on this forum in another thread about a Import Chinese Origin, Four Box Modular Class D Power Amp compared to a £50K Soulution Power Amp on a £200K system, or £150 400 system with the Import Amp. The system owner was completely bamboozled by the Import Amp being such a performer, the Soulution out performed it, but at £49 600 to attain the difference on offer. For the individual who was with the experience of the comparison, that becomes a very difficult decision to even consider. Even more painful, is that on the same occasion, a Neurchrome 365 at approx' £2K built, at times with certain tracks was much more attractive than the Soulution. |
Fosi V3 with a ton of mods is the best amp using a DAC that I have ever heard......and that includes my own wild dual mono Class A amps. Please see the bottom of this page for details and a pic. http://tweakaudio.com/EVS-2/DIY_Bi-amped_super_speaker.html My new open baffle speakers should be up and running next week.....check back for more info.....this is fun! |
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