Fosi Audio V3 Amplifier Review

[Mordor]

Im not tecnical guy, but i went for the 48V power supply, since i read it gives better sound and a little more muscle...

 

[Juampa1989]

Almost - 34 to 89W is just over 4dB

but bear in mind those SPL levels will be for the peaks in the music. Your average listening level (what you hear as volume) will likely be 10 to 20dB below that, depending on the style of music.

Oh, and also bear in mind - that for 4ohm speakers the sensitivity is normally rated at 2W, not at 1W, so if your speakers are 4ohm you lose 3dB right there.

If I understand, I measured the spl and it gives me a maximum of 97db listening to music and as you indicate it is the peak. Then it goes down to 86 - 89db in quieter passages and as I indicated it is enough for my room because if it doesn't it becomes very noisy.
I use a klipsch rp-160m

 

[Pareto Pragmatic]

I've been using mine for a few weeks now, $72 from Amazon, standard power supply. Compared to our "move it around many places" Aiyima D03 (TI 3116 chip iirc), there is no comparison. I put the Fosi on the shelf with a $350 5.1 AVR and a vintage amp I picked up for $80, to give me A/AB/D options in our living room. Fed with a Topping e30 ii DAC in DAC mode, and either CD via coax or 24/192 streaming via USB. Generally listened at 70-80 dB (75-85 peaks) at 8-14 feet from the speakers.

Given long listening sessions (all day sometimes), and plans for future speakers that will need more current from the 48v I plan to buy, I wanted the better heat control of the v3 compared to other 3255 chip based amps I have seen.

I am pretty much the ideal use case for "just an amp", nothing more needed. I can set my sub fine with it when I want a sub, but I think most people will do better waiting until there is a version where the volume controls the line out and it is not just a pass through. An alternative 3255 based amp might be easier to live with if you use a subwoofer and change volume a lot.

First impressions. Great with several inexpensive soft dome stand mount speakers I tried it with for all music. But for my wife's beloved 1984 Heresies (free to us, 20 years of play and then recapped and all drivers replaced from Crites one by one) still enough of class D "thinness" for horns on older jazz to make me not want to listen. OTOH, 1980s "alt" distortion filled stuff was wonderful! Everything else was "different, need more time to think about it and compare".

I gave myself time to adapt, but did not change my reaction to the sound of sax/trumpet during playback. After some experimentation, I found that changing the DAC from filter 3 to filter 1 (short delay/sharp roll off changed to sharp roll off) helped. I also towed the speakers out slightly from dead center toed in. Can I still hear some "thinness" on Kind of Blue? Only if I listen very closely or A/B check, so not enough to matter.

It's my go to amp for music in that room now, for all types of music that are well recorded. I'll still use other amps for recordings with issues, or to get a more "vintage sound" on pre 1980 recordings. If that's what I want to listen to that day.

I can't believe what $72 + $150 for the DAC puts out! This is a crazy performance level for the price.

 

[kelontong]

Can't tell the difference between the original output wires vs the copper wires I stuck in there. I did it because of my OCD more than anything else.

I have a bunch of op amps from when I was playing with a cmoy back in the day (NJM2068, OPA2134, OPA2227, LM4562, OPA1656, OPA1612, MUSES8820). I covered the top of chips with blue painter's tape and had my wife mark the pairs randomly. I listened to the op amps with the same tracks at identical volumes, and at least with my setup, I can't tell the difference between any of them and the stock NE5532. Maybe there will be a difference if measured with instruments, but I can't tell. Maybe it's because my ears have been ruined from all the years listening to tube amps with their ungodly amount of sweet, sweet harmonic distortion.

nothing beats tube amps in general....

 

[kelontong]

I've been using mine for a few weeks now, $72 from Amazon, standard power supply. Compared to our "move it around many places" Aiyima D03 (TI 3116 chip iirc), there is no comparison. I put the Fosi on the shelf with a $350 5.1 AVR and a vintage amp I picked up for $80, to give me A/AB/D options in our living room. Fed with a Topping e30 ii DAC in DAC mode, and either CD via coax or 24/192 streaming via USB. Generally listened at 70-80 dB (75-85 peaks) at 8-14 feet from the speakers.

Given long listening sessions (all day sometimes), and plans for future speakers that will need more current from the 48v I plan to buy, I wanted the better heat control of the v3 compared to other 3255 chip based amps I have seen.

I am pretty much the ideal use case for "just an amp", nothing more needed. I can set my sub fine with it when I want a sub, but I think most people will do better waiting until there is a version where the volume controls the line out and it is not just a pass through. An alternative 3255 based amp might be easier to live with if you use a subwoofer and change volume a lot.

First impressions. Great with several inexpensive soft dome stand mount speakers I tried it with for all music. But for my wife's beloved 1984 Heresies (free to us, 20 years of play and then recapped and all drivers replaced from Crites one by one) still enough of class D "thinness" for horns on older jazz to make me not want to listen. OTOH, 1980s "alt" distortion filled stuff was wonderful! Everything else was "different, need more time to think about it and compare".

I gave myself time to adapt, but did not change my reaction to the sound of sax/trumpet during playback. After some experimentation, I found that changing the DAC from filter 3 to filter 1 (short delay/sharp roll off changed to sharp roll off) helped. I also towed the speakers out slightly from dead center toed in. Can I still hear some "thinness" on Kind of Blue? Only if I listen very closely or A/B check, so not enough to matter.

It's my go to amp for music in that room now, for all types of music that are well recorded. I'll still use other amps for recordings with issues, or to get a more "vintage sound" on pre 1980 recordings. If that's what I want to listen to that day.

I can't believe what $72 + $150 for the DAC puts out! This is a crazy performance level for the price.

to listem"solid states vintage amp aka early 80s and older" you have to recap and rebuild your vintage amp. make sure no clipping and working properly (required osciloscope and audio generator: I usually use test from 10Hz to 10Khz in general), you will hear something different compared current amps model.

I bought recently from ali for $60 + taxes with standard 32V power brick.
did some comparison. my vintage amp(s) has soft-warm compared to fosi v3 that has tendency more metal (based on my ears haha.. this is subjective).

btw, AVR is not my recomendation for stereo in general. They build for home theater in their mind,

my subjective conclusion:
but for $60 ( I bought it with 32v power brick) class d amp with famous class D power chip. this is worth it for portability and small spaces.

 

[kelontong]

Can't tell the difference between the original output wires vs the copper wires I stuck in there. I did it because of my OCD more than anything else.

I have a bunch of op amps from when I was playing with a cmoy back in the day (NJM2068, OPA2134, OPA2227, LM4562, OPA1656, OPA1612, MUSES8820). I covered the top of chips with blue painter's tape and had my wife mark the pairs randomly. I listened to the op amps with the same tracks at identical volumes, and at least with my setup, I can't tell the difference between any of them and the stock NE5532. Maybe there will be a difference if measured with instruments, but I can't tell. Maybe it's because my ears have been ruined from all the years listening to tube amps with their ungodly amount of sweet, sweet harmonic distortion.

just for trial, I swap MUSES 02 : https://www.nisshinbo-microdevices.co.jp/en/MUSES/series/MUSES02.html and do NOT hear many differences . and I put original NE5532 (fosi uses original one based on my observation) back. let alone to use MUSES 02 in the DAC hehehe.

 

[burkm]

I don't think they can change to 36V/6A PSU, they need to purchase large amount of the same PSUs to get a competitive price from their PSU suppliers.

If they move to 36V/6A PSU, what te price should be?

The general choice of the 32V 5A PSU as standard might be driven by the idea, that the original amps sales price should be just below $100. It might not be the best choice as amirs test results show.

 

[Joe Smith]

I'm currently testing use of my old Nikko Beta 20 preamp to boost level between source and a Fosi V3 with the 32v power supply. I like being able to run the amp cooler with the 32v supply rather than with the 48v supply.

 

[cEbNVDyfMy]

Is it ok to leave this amp on, turned to max. it has no 12v trigger.

 

[antcollinet]

Is it ok to leave this amp on, turned to max. it has no 12v trigger.

It'll be no problem for the amp.

Just make sure your not going to send it a full scale signal by accident if you value your speakers.

 

[ewwwDavid]

Any reason the v3 wouldn’t be ideal with Wharfedale 12.0 for near field?

Sensitivity (2.83V @ 1m):	85dB
Recommended amp power:	20-60W
Peak SPL:	95dB
Nominal impedance:	8 Ω compatible
Minimum Impedance:	4 Ω
Frequency Response (+/-3dB):	70Hz-20kHz
Bass Extension (-6dB):	65Hz
Crossover Frequency:	2.7kHz
Cabinet Volume (in litres):	4.4L

 

[antcollinet]

Any reason the v3 wouldn’t be ideal with Wharfedale 12.0 for near field?

Sensitivity (2.83V @ 1m):	85dB
Recommended amp power:	20-60W
Peak SPL:	95dB
Nominal impedance:	8 Ω compatible
Minimum Impedance:	4 Ω
Frequency Response (+/-3dB):	70Hz-20kHz
Bass Extension (-6dB):	65Hz
Crossover Frequency:	2.7kHz
Cabinet Volume (in litres):	4.4L

No reason at all.

 

[Juampa1989]

Hello, I have a question, fosi indicates that the V3 has Sinad of 88db and a total harmonic distortion of 0.003%. Sinad measured it amirm and it is indeed 88db, but if it is transformed to total harmonic distortion it should be 0.006% which is equivalent to 88db. Because I understand that 0.003% equals 96 Sinad It's right?. This is to better understand that data. Greetings

 

[antcollinet]

Hello, I have a question, fosi indicates that the V3 has Sinad of 88db and a total harmonic distortion of 0.003%. Sinad measured it amirm and it is indeed 88db, but if it is transformed to total harmonic distortion it should be 0.006% which is equivalent to 88db. Because I understand that 0.003% equals 96 Sinad It's right?. This is to better understand that data. Greetings

Sinad stands for "Signal to Noise and Distortion"

So it is not only measuring THD - there is also noise included in the figure. Hence why THD alone seems to be better than the 88dB Sinad figure.

 

[Juampa1989]

Sinad significa "Señal de ruido y distorsión".

Por lo tanto, no sólo se mide la THD, sino que también se incluye el ruido en la figura. De ahí que el THD por sí solo parezca mejor que la cifra Sinad de 88 dB.

thank you i understand

 

[SuperDerpBro]

Got one of these last week. Didn't open it until an hour ago. Has a crooked knob. Which really bothers my OCD, lol. Is this something worth trying to make an exchange for?

 

[gasolin75]

picture

 

[SuperDerpBro]

picture

https://imgur.com/a/Z69129P

 

[gasolin75]

Take it out and look at the thread on the knob, if it's damaged,crooked

Is it metal or plastic ?

 

[SuperDerpBro]

I tried, briefly. to remove the knob, but it was super hard. I gave up cause I didn't want to break anything. heh