You mean like this?I have a 2.1 setup for office use and would love to see a stereo version of this with a sub out and adjustable high pass filter out to the speakers. That would be killer as I don't think one exists in any sort of reasonable price or small form factor.
Thanks, found it now. I zoomed the page and this part was hidden from meFosi Audio V3 Mono Monoblock Power Amplifier
The V3 MONO is a monoblock high-power amplifier integrated with the Texas Instruments TPA3255 amplifier chip, suitable for speakers of 2Ω to 8Ω impedance. It implements Post-Filter Feedback (PFFB) technology, addressing the long-standing issue of load-dependency in Class-D amplifiers.fosiaudio.com
look for:
View attachment 360762
Ah, but he does!If I didn’t know better I would think this is a well done April Fools joke. But Amir doesn’t joke!
Good to see.The V3 Mono is our first amp with PFFB implementation.
So the unit Amir tested was a pre-production version?The V3 Mono is currently in production
I think that is a big improvement. My impression has been that treble peaks, even if outside but near the audible range, can harden the sound and cause more irritation. Do I have objective data? No. But I am delighted to see that Fosi has eliminated that as a possibility.During the period we sent the set to Amir for testing, our R&D team did not stop optimizing the V3 Mono, and we have now further improved its frequency response curve. Below is the chart for your reference.
Hello: are the amps ever tested for power output using pink noise?Just read this from the company in their message to me when the amp was sent:
"We'll provide a bundle including two V3 mono amps and a 48V/10A psu for no more than 260USD. That single 48V/10A psu can power the two sets of v3 mono simultaneously."
Woah, why yes, just like the DTA-100ST. A Fosi bass management version would be amazing.You mean like this?
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Of there's this:
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Personally I think they should all have some sort of bass management built-in.
Back in 2019, when I bought my amazing Topping D90 I wrote them few emails that this is what I and the market are looking for. Since than they repeatedly produced various similar DACS and desktop amps with no remote....This is a review and detailed measurements of the Fosi Audio V3 Mono class D amplifier. It was sent to me by the company. The price with the power supply I tested is US $139.99.
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I must say the concept of a "monoblock" amplifier in such a small size runs foul of any expectation a longtime audiophile would have! But monblock it is even though it is a very small block. Controls are on/off/trigger audio and selection of XLR vs RCA inputs -- just like the big boys! I am not showing the sides of the amp but there are very large holes with attractive orange color grid showing through. Nice. Back panel is again a bit of a shock to the system seeing XLR input:
View attachment 360698
The power supply as noted, is quite beefy with 48 volts at 5 amps on tap (240 watts). The amplifier is stated to have PFFB implementation which for a class D amplifier means it should have no load dependency together with lower distortion. Let's see if we get these with our measurements.
Fosi Audio V3 Mono Amplifier Measurements
Let's start with XLR input:
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Wow, I did not expect this class of amplifier to break through the 100 dB SINAD barrier but the V3 Mono does exactly that, placing it in our prestigious category of "excellent:
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RCA input costs you some performance but I was relieved to not see any mains interference:
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Distortion is still at provably inaudible -115 dB. I like that the gain is nominal 25 which is my new recommendation for amplifiers.
Noise performance is excellent and at full power, darn near approaches sate of the art:
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Now the all important frequency response and load dependency test:
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There is essentially no impact up to 20 kHz between the 4 and 8 ohm indicating very low output impedance, albeit with a bit of peaking. Compare that to non-PFFB amps such as Fosi Audio V3 stereo Amp:
Above we have 2 dB differential at 20 kHz.
Distortion is very low and only increases with frequency:
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Let's see how much power we can get out of this little box:
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Efficiency must be quite high as we get essentially the power we put in (the power supply likely has some headroom).
There is decent amount of power even with 8 ohm and with very low noise:
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As note though, distortion does rise at higher frequencies:
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Fortunately it is good where our hearing is very sensitive (below 5 kHz).
I also threw my suite of my punishing reactive loads at it:
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Translating into watts:
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Amazing that this little amplifier can handle even 2 ohm load! Note that these are short term power ratings.
There may be a bit of power on noise:
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Conclusions
All I can say is wow! It is incredible how far these small amplifiers have come. It is the result of a manufacturer listening to our needs, implementing features such as balanced and trigger inputs, and proper feedback mechanism to essentially eliminate load dependency. I can't imagine asking for more from Fosi when it comes to such an amplifier. Everything is as good as you could possibly want.
It is my pleasure to recommend Fosi Audio V3 Mono amplifier.
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As always, questions, comments, recommendations, etc. are welcome.
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I gotta admit I'm baffled at the power handling of that IC!Ah, but he does!
Sony Tapecorder 101 Review (Vintage Reel to Reel)
This is a review and detailed measurements of the Sony Tapecorder Model 101 vintage Reel to Reel tape recorder. My brother found it for me at a Goodwill store. The 101 was released in 1959 and retailed for 29,800 Japanese Yen (today's conversion and adjusted for inflation: $2,377). I must stay...www.audiosciencereview.com
Good to see.
So the unit Amir tested was a pre-production version?
Thanks to @amirm for testing this amp, it sure packs a punch for a small chip amp.
View attachment 360766
JSmith
Maybe they finally provided the necessary heatsinking for this power output?What I find surprising is that the key ingredient, the TPA3255 chip from TI, has been around for… 8 (more?) years. Why did it take so long for somebody to figure out the successful recipe?
Kudos to Fosi Audio for listening to the users, and applying good engineering rather than chasing some esoteric BS audio paradigm.
If one imagines reallllly hard of course. LoL...I see the opamps are swapable. However, it doesn’t look like there is enough space for the boutique discrete opamps that audiophiles believe influence sound quality. I wonder if any other conventional opamps would offer better measured performance?
I am not showing the sides of the amp
Many holes... I gather cooling will not be an issue;I believe I can imagine why.