Fosi Audio V3 Mono Amplifier Review

[mrmeng430]

A poster on Fosi's Facebook is using this Power supply , has 48V 10A to power both V3monos. Any thoughts on this? This is used for DC connection.

 

[avdoc]

A poster on Fosi's Facebook is using this Power supply , has 48V 10A to power both V3monos. Any thoughts on this? This is used for DC connection.

I recommend separate 48v 5a power supplies for each amp. There have been issues running 2 off one 10a.

 

[CReeDeR]

Hello there,

I'm new to the forum. So far I have only been a silent reader. However, I now have a few questions that are giving me a bit of a headache and I was hoping that you might be able to help me.

I currently have a 7.1 system with OLED, projector etc. in my living room for gaming, watching films and series and other multimedia. I also enjoy listening to music a lot. Of course, if it's not multi-channel sources, I prefer stereo.

My chain for this currently looks like this:
WiiM Pro Plus > optical cable > Marantz SR6011 (in 'pure direct' mode) > RCA Pre Out > Fosi V3 stereo amplifier > to my favourite speakers.
The Fosi amp is turned up all the way. The volume is controlled via the Marantz.
I really enjoy listening to the whole thing.
Nevertheless, I ordered two Fosi V3 monos at the end of July, which have not yet been delivered. As I was unsure whether the monos would already have the corrected phase, I asked again and it was confirmed.
I ordered the monos with a 10 A power supply and the filter. Would it make more sense to power them separately with the existing 48 V 5 A GaN power supply of my stereo amp (and buy a second one)?

There was also a good offer for the Topping DX5 DAC, which I also ordered and which was delivered yesterday.

My plan was as follows:
Connect the WiiM Pro Plus to the Topping DX5 via an optical cable. From this with XLR to the monos and to my two speakers. I could then continue to connect the Marantz AVR to the monos via RCA Pre Out to continue using my speakers in the 7.1 system and simply switch the input on the monos as required.
So far so good.

My idea was actually to set the volume on the WiiM to 100% and adjust it on the Topping DAC (in 'Pre Amp' mode).
Actually, I was of the opinion that if a device like the Topping DAC has a pre-amp mode and a volume control, you could use it without any major worries.
But then I read the horror stories from one or a few users that their Topping E70 suddenly switched to full volume while listening and that this can happen with all digital volume controls.

I don't want to damage my beloved speakers or my ears. So now another question. Which of the following solutions would you advise me to use?

1. use the Topping DX5 for volume control as originally planned, because I'm just too worried.
2. to set the Topping to DAC mode (with full volume output and without the possibility of control) and to control the volume via the WiiM. However, this is also a digital volume control. But at least I could set a maximum volume with it.
3. turn the Topping up to full volume, then set the WiiM to the maximum volume at which I would listen and then adjust the volume while listening via the DAC. This would give me two 'safeguards', so to speak, with which a possible error would certainly not occur at the same time. The question is: does this setting result in any loss of sound quality?
4. a completely different solution? I don't want the chain to be any longer if it's not absolutely necessary.

I am also someone who always checks the volume before playing. But the problem is that I often listen without my wife being present. And since I'm a wheelchair user, I can't just jump up and rip the cables out of the wall in an emergency.

Questions upon questions.
Sorry for the long text and thank you in advance for your patience and any advice.

 

[Lux_ury]

Just out of curiosity what was the kick starter pricing, for two amps and one 48v 10amp brick?

 

[Lux_ury]

Hello there,

I'm new to the forum. So far I have only been a silent reader. However, I now have a few questions that are giving me a bit of a headache and I was hoping that you might be able to help me.

I currently have a 7.1 system with OLED, projector etc. in my living room for gaming, watching films and series and other multimedia. I also enjoy listening to music a lot. Of course, if it's not multi-channel sources, I prefer stereo.

My chain for this currently looks like this:
WiiM Pro Plus > optical cable > Marantz SR6011 (in 'pure direct' mode) > RCA Pre Out > Fosi V3 stereo amplifier > to my favourite speakers.
The Fosi amp is turned up all the way. The volume is controlled via the Marantz.
I really enjoy listening to the whole thing.
Nevertheless, I ordered two Fosi V3 monos at the end of July, which have not yet been delivered. As I was unsure whether the monos would already have the corrected phase, I asked again and it was confirmed.
I ordered the monos with a 10 A power supply and the filter. Would it make more sense to power them separately with the existing 48 V 5 A GaN power supply of my stereo amp (and buy a second one)?

There was also a good offer for the Topping DX5 DAC, which I also ordered and which was delivered yesterday.

My plan was as follows:
Connect the WiiM Pro Plus to the Topping DX5 via an optical cable. From this with XLR to the monos and to my two speakers. I could then continue to connect the Marantz AVR to the monos via RCA Pre Out to continue using my speakers in the 7.1 system and simply switch the input on the monos as required.
So far so good.

My idea was actually to set the volume on the WiiM to 100% and adjust it on the Topping DAC (in 'Pre Amp' mode).
Actually, I was of the opinion that if a device like the Topping DAC has a pre-amp mode and a volume control, you could use it without any major worries.
But then I read the horror stories from one or a few users that their Topping E70 suddenly switched to full volume while listening and that this can happen with all digital volume controls.

I don't want to damage my beloved speakers or my ears. So now another question. Which of the following solutions would you advise me to use?

1. use the Topping DX5 for volume control as originally planned, because I'm just too worried.
2. to set the Topping to DAC mode (with full volume output and without the possibility of control) and to control the volume via the WiiM. However, this is also a digital volume control. But at least I could set a maximum volume with it.
3. turn the Topping up to full volume, then set the WiiM to the maximum volume at which I would listen and then adjust the volume while listening via the DAC. This would give me two 'safeguards', so to speak, with which a possible error would certainly not occur at the same time. The question is: does this setting result in any loss of sound quality?
4. a completely different solution? I don't want the chain to be any longer if it's not absolutely necessary.

I am also someone who always checks the volume before playing. But the problem is that I often listen without my wife being present. And since I'm a wheelchair user, I can't just jump up and rip the cables out of the wall in an emergency.

Questions upon questions.
Sorry for the long text and thank you in advance for your patience and any advice.

Welcome
I keep it simple as possible, always have a Dac/preamp with Volume displayed as default and make sure it comes with remote control, so you can mute if need be, without struggling to reach. I'm sure someone can help in detail.

 

[early rejecter]

Just out of curiosity what was the kick starter pricing, for two amps and one 48v 10amp brick?

My card was billed $214 for that package.

 

[Lux_ury]

My card was billed $214 for that package.

Interesting thanks for sharing

 

[SMen]

Hello there,

I'm new to the forum. So far I have only been a silent reader. However, I now have a few questions that are giving me a bit of a headache and I was hoping that you might be able to help me.

I currently have a 7.1 system with OLED, projector etc. in my living room for gaming, watching films and series and other multimedia. I also enjoy listening to music a lot. Of course, if it's not multi-channel sources, I prefer stereo.

My chain for this currently looks like this:
WiiM Pro Plus > optical cable > Marantz SR6011 (in 'pure direct' mode) > RCA Pre Out > Fosi V3 stereo amplifier > to my favourite speakers.
The Fosi amp is turned up all the way. The volume is controlled via the Marantz.
I really enjoy listening to the whole thing.
Nevertheless, I ordered two Fosi V3 monos at the end of July, which have not yet been delivered. As I was unsure whether the monos would already have the corrected phase, I asked again and it was confirmed.
I ordered the monos with a 10 A power supply and the filter. Would it make more sense to power them separately with the existing 48 V 5 A GaN power supply of my stereo amp (and buy a second one)?

There was also a good offer for the Topping DX5 DAC, which I also ordered and which was delivered yesterday.

My plan was as follows:
Connect the WiiM Pro Plus to the Topping DX5 via an optical cable. From this with XLR to the monos and to my two speakers. I could then continue to connect the Marantz AVR to the monos via RCA Pre Out to continue using my speakers in the 7.1 system and simply switch the input on the monos as required.
So far so good.

My idea was actually to set the volume on the WiiM to 100% and adjust it on the Topping DAC (in 'Pre Amp' mode).
Actually, I was of the opinion that if a device like the Topping DAC has a pre-amp mode and a volume control, you could use it without any major worries.
But then I read the horror stories from one or a few users that their Topping E70 suddenly switched to full volume while listening and that this can happen with all digital volume controls.

I don't want to damage my beloved speakers or my ears. So now another question. Which of the following solutions would you advise me to use?

1. use the Topping DX5 for volume control as originally planned, because I'm just too worried.
2. to set the Topping to DAC mode (with full volume output and without the possibility of control) and to control the volume via the WiiM. However, this is also a digital volume control. But at least I could set a maximum volume with it.
3. turn the Topping up to full volume, then set the WiiM to the maximum volume at which I would listen and then adjust the volume while listening via the DAC. This would give me two 'safeguards', so to speak, with which a possible error would certainly not occur at the same time. The question is: does this setting result in any loss of sound quality?
4. a completely different solution? I don't want the chain to be any longer if it's not absolutely necessary.

I am also someone who always checks the volume before playing. But the problem is that I often listen without my wife being present. And since I'm a wheelchair user, I can't just jump up and rip the cables out of the wall in an emergency.

Questions upon questions.
Sorry for the long text and thank you in advance for your patience and any advice.

Regarding "Would it make more sense to power them separately with the existing 48 V 5 A GaN power supply of my stereo amp (and buy a second one)"?
I use the 10 A and somewhere there is a filter I've yet to plug in ... my two monos sit adjacent to a decent sized TV screen, and then on to a pair of speakers (also special to me).

Many will chime in here saying go with the two supplies. I would also if my plug sockets and system layout benefited. As it is right now the additional supply would simply join the others behind my television!

The best volume control I have yet to find is a relay switched device - it's 'physical' and so I don't worry about sudden max volume surging through to my speakers. It is also fully balanced, but gives dual single ended also, from balanced input, useful for line level connection to subwoofer(s).

It is however an additional step in the chain, and so not absolutely necessary. Appears to be for chinese enthusiasts (and not export market dumping)! Very transparent! You need to like blue leds though... I find it superb with balanced in to balanced out, and you could probably run a cable to have it near by your location, benefiting from balanced cable lengths.

I appreciate this is dinosaur stuff not having a remote control, but I could only find it with manual control... but it just doesn't seem to get in the way of the (balanced) signal ... sounding superbly as if it is not there at all!

And for not all that much more than an additional power supply!

 

[Brian Hall]

A poster on Fosi's Facebook is using this Power supply , has 48V 10A to power both V3monos. Any thoughts on this? This is used for DC connection.

I went with two power supplies and have them plugged into different, separate outlets. The extra space taken up by one more power brick is not a big deal.

 

[Brian Hall]

Hello there,

I'm new to the forum. So far I have only been a silent reader. However, I now have a few questions that are giving me a bit of a headache and I was hoping that you might be able to help me.

I currently have a 7.1 system with OLED, projector etc. in my living room for gaming, watching films and series and other multimedia. I also enjoy listening to music a lot. Of course, if it's not multi-channel sources, I prefer stereo.

My chain for this currently looks like this:
WiiM Pro Plus > optical cable > Marantz SR6011 (in 'pure direct' mode) > RCA Pre Out > Fosi V3 stereo amplifier > to my favourite speakers.
The Fosi amp is turned up all the way. The volume is controlled via the Marantz.
I really enjoy listening to the whole thing.
Nevertheless, I ordered two Fosi V3 monos at the end of July, which have not yet been delivered. As I was unsure whether the monos would already have the corrected phase, I asked again and it was confirmed.
I ordered the monos with a 10 A power supply and the filter. Would it make more sense to power them separately with the existing 48 V 5 A GaN power supply of my stereo amp (and buy a second one)?

There was also a good offer for the Topping DX5 DAC, which I also ordered and which was delivered yesterday.

My plan was as follows:
Connect the WiiM Pro Plus to the Topping DX5 via an optical cable. From this with XLR to the monos and to my two speakers. I could then continue to connect the Marantz AVR to the monos via RCA Pre Out to continue using my speakers in the 7.1 system and simply switch the input on the monos as required.
So far so good.

My idea was actually to set the volume on the WiiM to 100% and adjust it on the Topping DAC (in 'Pre Amp' mode).
Actually, I was of the opinion that if a device like the Topping DAC has a pre-amp mode and a volume control, you could use it without any major worries.
But then I read the horror stories from one or a few users that their Topping E70 suddenly switched to full volume while listening and that this can happen with all digital volume controls.

I don't want to damage my beloved speakers or my ears. So now another question. Which of the following solutions would you advise me to use?

1. use the Topping DX5 for volume control as originally planned, because I'm just too worried.
2. to set the Topping to DAC mode (with full volume output and without the possibility of control) and to control the volume via the WiiM. However, this is also a digital volume control. But at least I could set a maximum volume with it.
3. turn the Topping up to full volume, then set the WiiM to the maximum volume at which I would listen and then adjust the volume while listening via the DAC. This would give me two 'safeguards', so to speak, with which a possible error would certainly not occur at the same time. The question is: does this setting result in any loss of sound quality?
4. a completely different solution? I don't want the chain to be any longer if it's not absolutely necessary.

I am also someone who always checks the volume before playing. But the problem is that I often listen without my wife being present. And since I'm a wheelchair user, I can't just jump up and rip the cables out of the wall in an emergency.

Questions upon questions.
Sorry for the long text and thank you in advance for your patience and any advice.

Unless you need extra features or extra inputs from the Topping, you can eliminate it and just use the Wiim Pro Plus as your preamp, streamer and dac. The Topping won't sound any better than the dac in the Pro Plus.

 

[Young Moon]

Power unit I use the Mean Well LRS-350-48 unit. Grounding is also possible, allowing for cleaner DC current.

 

[antcollinet]

it's 'physical' and so I don't worry about sudden max volume surging through to my speakers.

Not really any more reliable than any software controlled volume.

The relays are controlled from a microcontroller, and the "state" (volume) has to be remembered when powered off (and not corrupted/lost while powered on). It is no less likely to forget what the volume should be than any other system not consisting of an actual potentiometer.

In an ideal world in this type of system, the volume "value" should be checksummed, and revert to minimum if the checksum doesn't match. I'm not sure if the designers of these types of devices are that careful though.

The best defence from software controlled volume, is to use attenuators on the input to the amp which limit the maximum volume to a safe level for your speakers - even when the volume control is set to max.

 

[SMen]

Unless you need extra features or extra inputs from the Topping, you can eliminate it and just use the Wiim Pro Plus as your preamp, streamer and dac. The Topping won't sound any better than the dac in the Pro Plus.

I think the Wiim Pro Plus is single ended only. So this loses the ability to switch between RCA and Balanced to the Monos from the Marantz (single ended) @CReeDeR mentions. I'm loving the balanced connections through to the V3 Monos because it works in my set up.

 

[Brian Hall]

I think the Wiim Pro Plus is single ended only. So this loses the ability to switch between RCA and Balanced to the Monos from the Marantz (single ended) @CReeDeR mentions. I'm loving the balanced connections through to the V3 Monos because it works in my set up.

Unless you have ground hum issues, there is no real audio benefit to using balanced connections over RCA.

 

[SMen]

Not really any more reliable than any software controlled volume.

The relays are controlled from a microcontroller, and the "state" (volume) has to be remembered when powered off (and not corrupted/lost while powered on). It is no less likely to forget what the volume should be than any other system not consisting of an actual potentiometer.

In an ideal world in this type of system, the volume "value" should be checksummed, and revert to minimum if the checksum doesn't match. I'm not sure if the designers of these types of devices are that careful though.

The best defence from software controlled volume, is to use attenuators on the input to the amp which limit the maximum volume to a safe level for your speakers - even when the volume control is set to max.

My DAC with internal volume control does seem to remember the previous volume, even when unplugged. I haven't tested it after being off for 24 hours or so. My assumption is that it is DAC first, and volume control second so I would never just power on without checking.

The problem with volume controls, especially multiple volume controls in the signal path, is that they can affect the sound quality. They are probably / surely / one of the most influential items in a traditional (not digital) pre-amp.

There are so many amps these days where users can set the volume 'physically' to max, and forget the other control elsewhere in the chain! Never mind any malfunctions!

Let's say there is a power cut, do, for example the Schitt audio Freya pre-amp relay attenuators default to 100%, and rotate to maximum on switch on? I'm pretty sure that if they did, they would require a product call back, or the feedback would be pretty horrendous (verbal written feedback)! There are plenty of users of these pre-amps who have not reported a problem of this nature.

 

[SMen]

Unless you have ground hum issues, there is no real audio benefit to using balanced connections over RCA.

If you check back, the original poster is benefiting from the ability to switch sources - so he is using the RCA connections for one source, and the balanced for the other, and is able to switch by this means.

 

[antcollinet]

My DAC with internal volume control does seem to remember the previous volume, even when unplugged. I haven't tested it after being off for 24 hours or so. My assumption is that it is DAC first, and volume control second so I would never just power on without checking.

The problem with volume controls, especially multiple volume controls in the signal path, is that they can affect the sound quality. They are probably / surely / one of the most influential items in a traditional (not digital) pre-amp.

There are so many amps these days where users can set the volume 'physically' to max, and forget the other control elsewhere in the chain! Never mind any malfunctions!

Let's say there is a power cut, do, for example the Schitt audio Freya pre-amp relay attenuators default to 100%, and rotate to maximum on switch on? I'm pretty sure that if they did, they would require a product call back, or the feedback would be pretty horrendous (verbal written feedback)! There are plenty of users of these pre-amps who have not reported a problem of this nature.

I agree. The problem has been reported here - but It must be very rare.

I personally have never experienced it across a range of software based volume controls, including three different AVRs, a MiniDSP flex, external sound cards, and all the computers I've ever owned.

 

[whit]

Unless you have ground hum issues, there is no real audio benefit to using balanced connections over RCA.

Not my experience. It may well have to do with specific equipment, and how each has been implemented in it. In my case, going from an Emotiva ERC-3 CD player (taking advantage of its DAC, so running analog from it) to a Yamaha CX-A5100 pre-pro, the sound via XLR is distinctly superior to RCA . There's no hum issue either way. This is using Blue Jeans cables for RCA cables, compared to no-name XLR.

I note the Fosi mono for instance runs the RCA signals through an extra op-amp to convert to a balanced signal on the way in. If op-amps do color sound at all (no personal opinion on that), that could make a difference. Discussion elsewhere has it that some amp architectures take fuller advantage of a balanced signal input than others. The question might then be double: Does it accept XLR, and if so does it really take advantage of it? This is (per the cute cliche) above my pay grade.

 

[antcollinet]

This is (per the cute cliche) above my pay grade

Not above mine though.

No, op amps don't colour the sound - as evidenced by the dozens of op amps the music has already gone through before reaching your amp.
Both the XLR AND RCA inputs measure as transparent. There is no audible difference between them.

Your experience with your CD player is most likely due to the two inputs not being level matched - or just plain old sighted listening perceptive bias - which we are all subject to.

 

[SMen]

Not above mine though.

No, op amps don't colour the sound - as evidenced by the dozens of op amps the music has already gone through before reaching your amp.
Both the XLR AND RCA inputs measure as transparent. There is no audible difference between them.

Your experience with your CD player is most likely due to the two inputs not being level matched - or just plain old sighted listening perceptive bias - which we are all subject to.

Not sure about the "dozens of op amps" argument to support any impact real or imagined changes due to swapping op amps in a buffer or pre-amplifier stage.
A lot of music now is sent directly to an ADC, mixed digitally, and then distributed digitally. The listening done to perform the mix will have opamps in play for sure, but not the mix...
Or my record player to ADC and then back to DAC again.
That is not dozens. Just saying.
Some of our favorite recordings from yesteryear had minimum stages between the performance and the recording and sound better for it - are even sought after for it - because they outperform overly processed recordings - perhaps with too many op amps in the signal path - from later years.
There is an argument in that too... Too many op amps in the signal path color or reduce the fidelity of the original recording.