Fosi Audio V3 Amplifier Review

[Schlippwhip68]

Aiyima needs to step their game up bruh!

 

[Doodski]

I would recommend 36v 5A over the 48v 5A. Not wishing to throw a wet blanket over your buzz and 48v will be fine, but personally I just think the 36v 5A is the sweet spot for this amp.

Can you define sweet spot? I don't get it. The amp performs fine at 48 V DC and the power supply sags and gives the amp breathing/cooling room. What else do you want to see?

 

[Toku]

The Fosi Audio V3 I ordered today arrived and I tested it immediately.
I connected Topping E50 for DAC and Quad S2 for speaker. The included power supply unit is 32V. The comparison amplifiers are AIYIMA A07/A04, SMSL AO200 and A300.

I ordered it because I thought it came with the orange knob that was introduced in the Youtube video, but it was not included in the product sent from Amazon.jp. I feel cheated by Fosi.

As I have pointed out many times before, the taper A volume pot makes volume control very smooth. The change in volume relative to the rotation angle of the knob is now natural. Furthermore, I no longer feel the gang error at low volume.
The volume knob is made of solid aluminum and has a luxurious feel when operated.

The 3.5mm Pre-Out can be used for both input and output by simply connecting and branching the RCA inputs in parallel.

I thought turning the power on/off was a push operation of the volume knob, but it was an old-fashioned knob rotation operation. I don't like this method of operation. It's like old TV and radio.
I didn't feel any pop noise when turning the power on and off, which I always worry about with class D amplifiers. Also, I don't feel any noise from the speaker when there is no sound, even if I put my ear to the speaker.
The heat generation of the main unit is hardly felt with the attached 32V power supply. Test with a separate 48V power supply.

I think the main concern with the V3 is sound quality.
My first impression is that it adds a little more smoothness to the Class D sound. For me, who likes monitor-like sounds, the V3's resolution, sound field, three-dimensional sound, and frequency range all match my tastes.
When I compare the sound quality with the AIYIMA A07/A04, I feel a subtle difference in character between the two. The sound of V3 is like adding elegance to A07/A04. Both are great for me considering the price.
Based on the results so far, I really like the V3. But I'm terribly disappointed that the V3 I received didn't have the orange knobs in the box.

 

[Schlippwhip68]

The Fosi Audio V3 I ordered today arrived and I tested it immediately.
I connected Topping E50 for DAC and Quad S2 for speaker. The included power supply unit is 32V. The comparison amplifiers are AIYIMA A07/A04, SMSL AO200 and A300.

I ordered it because I thought it came with the orange knob that was introduced in the Youtube video, but it was not included in the product sent from Amazon.jp. I feel cheated by Fosi.

As I have pointed out many times before, the taper A volume pot makes volume control very smooth. The change in volume relative to the rotation angle of the knob is now natural. Furthermore, I no longer feel the gang error at low volume.
The volume knob is made of solid aluminum and has a luxurious feel when operated.

The 3.5mm Pre-Out can be used for both input and output by simply connecting and branching the RCA inputs in parallel.

I thought turning the power on/off was a push operation of the volume knob, but it was an old-fashioned knob rotation operation. I don't like this method of operation. It's like old TV and radio.
I didn't feel any pop noise when turning the power on and off, which I always worry about with class D amplifiers. Also, I don't feel any noise from the speaker when there is no sound, even if I put my ear to the speaker.
The heat generation of the main unit is hardly felt with the attached 32V power supply. Test with a separate 48V power supply.

I think the main concern with the V3 is sound quality.
My first impression is that it adds a little more smoothness to the Class D sound. For me, who likes monitor-like sounds, the V3's resolution, sound field, three-dimensional sound, and frequency range all match my tastes.
When I compare the sound quality with the AIYIMA A07/A04, I feel a subtle difference in character between the two. The sound of V3 is like adding elegance to A07/A04. Both are great for me considering the price.
Based on the results so far, I really like the V3. But I'm terribly disappointed that the V3 I received didn't have the orange knobs in the box.

I happily paid for mine copper/orange knob separately to the amplifier with Fosi Audio on Ali Express. It’s quite clear that it is a separate order there on Ali Express.

 

[ClassicGuy]

The Fosi Audio V3 I ordered today arrived and I tested it immediately.
I connected Topping E50 for DAC and Quad S2 for speaker. The included power supply unit is 32V. The comparison amplifiers are AIYIMA A07/A04, SMSL AO200 and A300.

I ordered it because I thought it came with the orange knob that was introduced in the Youtube video, but it was not included in the product sent from Amazon.jp. I feel cheated by Fosi.

As I have pointed out many times before, the taper A volume pot makes volume control very smooth. The change in volume relative to the rotation angle of the knob is now natural. Furthermore, I no longer feel the gang error at low volume.
The volume knob is made of solid aluminum and has a luxurious feel when operated.

The 3.5mm Pre-Out can be used for both input and output by simply connecting and branching the RCA inputs in parallel.

I thought turning the power on/off was a push operation of the volume knob, but it was an old-fashioned knob rotation operation. I don't like this method of operation. It's like old TV and radio.
I didn't feel any pop noise when turning the power on and off, which I always worry about with class D amplifiers. Also, I don't feel any noise from the speaker when there is no sound, even if I put my ear to the speaker.
The heat generation of the main unit is hardly felt with the attached 32V power supply. Test with a separate 48V power supply.

I think the main concern with the V3 is sound quality.
My first impression is that it adds a little more smoothness to the Class D sound. For me, who likes monitor-like sounds, the V3's resolution, sound field, three-dimensional sound, and frequency range all match my tastes.
When I compare the sound quality with the AIYIMA A07/A04, I feel a subtle difference in character between the two. The sound of V3 is like adding elegance to A07/A04. Both are great for me considering the price.
Based on the results so far, I really like the V3. But I'm terribly disappointed that the V3 I received didn't have the orange knobs in the box.

Not sure how the Amazon Japan listing looks, but in the US the Amazon listing shows the unit with black knob and does not mention the orange knob at all, so there is no confusion there. I do wish they include the orange knob.

 

[Tangband]

The Fosi Audio V3 I ordered today arrived and I tested it immediately.
I connected Topping E50 for DAC and Quad S2 for speaker. The included power supply unit is 32V. The comparison amplifiers are AIYIMA A07/A04, SMSL AO200 and A300.

I ordered it because I thought it came with the orange knob that was introduced in the Youtube video, but it was not included in the product sent from Amazon.jp. I feel cheated by Fosi.

As I have pointed out many times before, the taper A volume pot makes volume control very smooth. The change in volume relative to the rotation angle of the knob is now natural. Furthermore, I no longer feel the gang error at low volume.
The volume knob is made of solid aluminum and has a luxurious feel when operated.

The 3.5mm Pre-Out can be used for both input and output by simply connecting and branching the RCA inputs in parallel.

I thought turning the power on/off was a push operation of the volume knob, but it was an old-fashioned knob rotation operation. I don't like this method of operation. It's like old TV and radio.
I didn't feel any pop noise when turning the power on and off, which I always worry about with class D amplifiers. Also, I don't feel any noise from the speaker when there is no sound, even if I put my ear to the speaker.
The heat generation of the main unit is hardly felt with the attached 32V power supply. Test with a separate 48V power supply.

I think the main concern with the V3 is sound quality.
My first impression is that it adds a little more smoothness to the Class D sound. For me, who likes monitor-like sounds, the V3's resolution, sound field, three-dimensional sound, and frequency range all match my tastes.
When I compare the sound quality with the AIYIMA A07/A04, I feel a subtle difference in character between the two. The sound of V3 is like adding elegance to A07/A04. Both are great for me considering the price.
Based on the results so far, I really like the V3. But I'm terribly disappointed that the V3 I received didn't have the orange knobs in the box.

I have both a04 and a07, with lm4562 Op.
Can you describe what you mean with adding elegance ? Is the V3 softer sounding , or less dynamic ?

 

[Schlippwhip68]

I have both a04 and a07, with lm4562 Op.
Can you describe what you mean with adding elegance ? Is the V3 softer sounding , or less dynamic ?

Less industrial looking case, more refined appearance.

 

[Toku]

I have both a04 and a07, with lm4562 Op.
Can you describe what you mean with adding elegance ? Is the V3 softer sounding , or less dynamic ?

How to feel sound quality varies from person to person, and opinions may differ completely.
It's just a translation of the difference I felt, so please imagine it as you see fit.
Since V3 and A07 are amps using the same TPA3255, their sound tendencies are very similar.
Dynamics are very similar. However, if you listen while switching between the two, you will notice that the sound is subtly different.
To me, it's difference detection, not good or bad sound quality. I always have trouble explaining this difference.
I also bought a lot of OPA4562, MUSE, etc. I have tried it with A07/A04. I can detect a slight difference from the original NE5532, but I didn't feel a clear advantage, so I haven't tried it since.

 

[cyclo]

I now have had more time with the Fosi Audio V3, first hooked up to a WiiM Mini and Paradigm Atom v7 speakers (pics on the previous pages) and now hooked up to a Marantz Pre Pro that is the center of a home theater system. The V3 in this current setup powers Infinity Modulus speakers. Also connected to the sub out of the Pre Pro is an SVS PB3000 sub. The V3 replaces the A07 which in turn replaced a Marantz PM-94 Quarter A stereo integrated amplifier that gave up the ghost a few weeks ago after more than 30 years of service. In the current setup the inputs are a WiiM Pro and an Apple TV 4k v3. WiiM pro is connected to the Marantz Pre Pro via a digital coax cable and the DAC I am using is the one on the Marantz Pre Pro.

On the previous setup, I took the opportunity to connect an old headphone to the rca output of the Fosi Audio V3. I can confirm that this is a fixed output and not connected to the volume control of the amp.

After about two hours of listening to a variety of music... jazz, recordings with mostly female vocals, rock, some classical, heavy metal, the Fosi Audio V3 temps hovered around 40C. This is with the 48V 5A PSU.

Overall, I am happy with the V3's performance. Do I detect a difference compared with the A07 or the Marantz PM-94 on this latest setup? I would be lying if I said yes. All I can say is at high volume levels listening to heavy metal tracks, I could not detect any audible distortion. In no way was the amp sounding strained. The instruments were still clear. On more "refined" jazz tracks and those featuring female vocals and acoustic instruments, the soundstage and imaging (again on this setup), separation were just as good as those of the other amps.

Sampling of the music I listened to to test the amp:

Mixed Test Tracks on Spotify

Heavy Metal Soundtracks

All Female Vocals

Uptempo Jazz

 

[feedbackloop]

ATTENTION
contrary to what I had initially written, the 3.5 mm jack output is NOT controlled by the volume potentiometer, but has a fixed low voltage output, active even when the amplifier is off, it is not a preout output, it is a bypass of the RCA source .
View attachment 294339

Is the output signal at the same level of the input (which would make it a true bypass like out), attenuated, fixed?

Sorry, I read it better.

So it's a fixed attenuated output.

Anyway, in the bt20a pro users are reporting a fully functioning pre-out output controlled by the volume knob.

Maybe a better alternative for subwoofer users.

 

[Schlippwhip68]

I now have had more time with the Fosi Audio V3, first hooked up to a WiiM Mini and Paradigm Atom v7 speakers (pics on the previous pages) and now hooked up to a Marantz Pre Pro that is the center of a home theater system. The V3 in this current setup powers Infinity Modulus speakers. Also connected to the sub out of the Pre Pro is an SVS PB3000 sub. The V3 replaces the A07 which in turn replaced a Marantz PM-94 Quarter A stereo integrated amplifier that gave up the ghost a few weeks ago after more than 30 years of service. In the current setup the inputs are a WiiM Pro and an Apple TV 4k v3. WiiM pro is connected to the Marantz Pre Pro via a digital coax cable and the DAC I am using is the one on the Marantz Pre Pro.

View attachment 294388View attachment 294389

On the previous setup, I took the opportunity to connect an old headphone to the rca output of the Fosi Audio V3. I can confirm that this is a fixed output and not connected to the volume control of the amp.

View attachment 294390

After about two hours of listening to a variety of music... jazz, recordings with mostly female vocals, rock, some classical, heavy metal, the Fosi Audio V3 temps hovered around 40C. This is with the 48V 5A PSU.

View attachment 294391

Overall, I am happy with the V3's performance. Do I detect a difference compared with the A07 or the Marantz PM-94 on this latest setup? I would be lying if I said yes. All I can say is at high volume levels listening to heavy metal tracks, I could not detect any audible distortion. In no way was the amp sounding strained. The instruments were still clear. On more "refined" jazz tracks and those featuring female vocals and acoustic instruments, the soundstage and imaging (again on this setup), separation were just as good as those of the other amps.

Sampling of the music I listened to to test the amp:

Mixed Test Tracks on Spotify

Heavy Metal Soundtracks

All Female Vocals

Uptempo Jazz

Thankyou. That’s very commendable performance with a 48v power supply.

 

[TheBatsEar]

the 3.5 mm jack output is NOT controlled by the volume potentiometer, but has a fixed low voltage output, active even when the amplifier is off, it is not a preout output, it is a bypass of the RCA source .

@amirm I suppose Fosi has identified you as a prime influencer, as is evidenced by them dropping codes and a bit of support here, and so your word with them will have some weight. Would you mind telling them they should not waste any money on features that are essentially useless, instead either lower the price?
Imagine something like this happening in a cheap Japanese or Bri'ish integrated, the forum wouldn't hesitate to send F-35. ;-)

One can do that , but maybe ( in that case ) better saving some for the dedicated poweramp Audiophonics Hypex amplifier

The old "just buy some better for 5x more money" ;-). Most people that buy these amps can't afford to, it's as simple as that.

That said, as you had the device open and maybe you have made a pic to look at, is there a place where we can grab the signal after the potentiometer and route it to the pre-out? Maybe like so:

• Isolate the fake "pre-out" from the main board by cutting it's traces on the board
• Solder some cable to the right solder-points of the potentiometer
• Solder the other end to the isolated "pre-out", making it a real pre-out?

And maybe another mod that would bypass the potentiometer too?

 

[feedbackloop]

@amirm I suppose Fosi has identified you as a prime influencer, as is evidenced by them dropping codes and a bit of support here, and so your word with them will have some weight. Would you mind telling them they should not waste any money on features that are essentially useless, instead either lower the price?
Imagine something like this happening in a cheap Japanese or Bri'ish integrated, the forum wouldn't hesitate to send F-35. ;-)


The old "just buy some better for 5x more money" ;-). Most people that buy these amps can't afford to, it's as simple as that.

That said, as you had the device open and maybe you have made a pic to look at, is there a place where we can grab the signal after the potentiometer and route it to the pre-out? Maybe like so:

• Isolate the fake "pre-out" from the main board by cutting it's traces on the board
• Solder some cable to the right solder-points of the potentiometer
• Solder the other end to the isolated "pre-out", making it a real pre-out?

And maybe another mod that would bypass the potentiometer too?

I'm a bit confused.

Isn't a pre-out supposed to pick the signal after the preamp stage (= preamplified), not just after the pot (input attenuator)?

 

[Schlippwhip68]

Can you define sweet spot? I don't get it. The amp performs fine at 48 V DC and the power supply sags and gives the amp breathing/cooling room. What else do you want to see?

Not maxed out voltage and not underpowered for personal preference. I’m not doubting the amps performance at all. Just a personal preference.

 

[TheBatsEar]

I ordered it because I thought it came with the orange knob that was introduced in the Youtube video, but it was not included in the product sent from Amazon.jp. I feel cheated by Fosi.

I think the orange knob was only for those that ordered it on Kickstarter or where deemed influencers. I didn't expect to get that knob when i ordered mine from Aliexpress.
Anyway, your posts sound to me like you have a bunch of old amps and parts around where you can nick a sweet knob any time.

As I have pointed out many times before, the taper A volume pot makes volume control very smooth. The change in volume relative to the rotation angle of the knob is now natural. Furthermore, I no longer feel the gang error at low volume.

Sweet

The volume knob is made of solid aluminum and has a luxurious feel when operated.

Once you pull the knob, would you mind measuring the shaft? It would help those that want to order a nice wooden knob online.

The 3.5mm Pre-Out can be used for both input and output by simply connecting and branching the RCA inputs in parallel.

So the 3.5mm and RCA connectors are connected. It's like a Y-RCA-cable. Not even saying what i think about that.

Based on the results so far, I really like the V3.

In the end that is what counts, it's supposed to be a cheap and good amplifier. Despite all the rants that seems to check out.

Isn't a pre-out supposed to pick the signal after the preamp stage (= preamplified), not just after the pot (input attenuator)?

Yes. But in this case i suspect a ESL marketeer designed the printings on the enclosure. The signal is coming from upstream, say a CD player, i suspect that person never used hifi gear and thought that is what pre-amp means. Nobody would have been confused if the marking would be "Line In/Out".

 

[dr_mick51]

How to feel sound quality varies from person to person, and opinions may differ completely.
It's just a translation of the difference I felt, so please imagine it as you see fit.
Since V3 and A07 are amps using the same TPA3255, their sound tendencies are very similar.
Dynamics are very similar. However, if you listen while switching between the two, you will notice that the sound is subtly different.
To me, it's difference detection, not good or bad sound quality. I always have trouble explaining this difference.
I also bought a lot of OPA4562, MUSE, etc. I have tried it with A07/A04. I can detect a slight difference from the original NE5532, but I didn't feel a clear advantage, so I haven't tried it since.

I had a great time last night. I could say that for the first time I could somehow feel some kind of PRAT. I mean I could not stop snapping my fingers and tapping with my toes. I had a blast.
My speakers are the Hivi Swans DIY3.1 with the perfectionist crossover mods using better capacitor and some bypass caps on top of it. And I'm using DSP for a flat frequency response.
This Fosi amp is a real winner for the price and some opamp replacements. Recommended.

 

[sarumbear]

I ordered it because I thought it came with the orange knob that was introduced in the Youtube video, but it was not included in the product sent from Amazon.jp. I feel cheated by Fosi.
…
Based on the results so far, I really like the V3. But I'm terribly disappointed that the V3 I received didn't have the orange knobs in the box.

So they ordered a device looking at a photograph of it that shows a black knob, after reading the review that also shows a black knob but they feel cheated because the knob on the amplifier they received is not orange as it is on a different model.

Some people have a weird understanding of marketing…

 

[Schlippwhip68]

I would be interested in finding out whether bipolar or fet op amps would be the best for the v3. I’m interested because I have fets in my BRZHIFI 3255XLR which can also house bipolar but fets are better for the circuitry…

 

[GGroch]

So they ordered a device looking at a photograph of it that shows a black knob, after reading the review that also shows a black knob but they feel cheated because the knob on the amplifier they received is not orange as it is on a different model.

Toku states his disappointment is because reviewers of the V3 said it came with 2 knobs. Kickstarter (and probably review samples) did come with 2 knobs. In the U.S. the orange knob is available at the Fosi Store for pre-order.

I am a bit annoyed at reviewers because most implied or stated the "Pre-Out" was variable. That's the risk you take at being 1st on the list. Mine arrives today.

 

[Tangband]

Maybe repost, but an interesting technical teardown and analysis of the V3 and a07.

The output coils and ventilation of the chassie and the volumepot seems to be better in V3 .