Fosi Audio V3 Mono Amplifier Review

[TonyJZX]

this sort of launch gives you an idea of what companies have to do when they release new products

i'm not in the consumer electronics space but i've been in the background of a few large product launches here and this sort of thing isnt unusual

and these are relatively simple devices

 

[SMen]

It occurs to me that the people here who want to try op amp changes could usefully A/B a mono track, and switch between one mono unit with one set of opamps, and the other with stock NE5532's. Put the speakers next to each other. Get a mate (or suitable relation) to switch so the listener is blind. This ought to settle things for the experimenters (themselves) - could they identify which was which?

A whole new purpose for mono power amps . Think I might give this a go for the hell of it. Rope in my kids.

 

[iLoveCats]

Looks like the full ASR lifecycle on this has been reached before it's even been in the average consumers hand. The foreshadowing, the reveal, the test and now the peanut gallery burying the product before it ships.

 

[olieb]

Looks like the full ASR lifecycle on this has been reached before it's even been in the average consumers hand. The foreshadowing, the reveal, the test and now the peanut gallery burying the product before it ships.

Yep!
Hey @Fosi Audio !
When do you plan to bring us the version 2? Everybody is eagerly waiting already.

At least it is now clear, why they did not start with the stereo, but brought a niche product first.

 

[Deleted member 72219]

Looks like the full ASR lifecycle on this has been reached before it's even been in the average consumers hand. The foreshadowing, the reveal, the test and now the peanut gallery burying the product before it ships.

Really…although the short story really seems to be that if you just use separate power supplies, it will sound great, even single-ended, where an imperceptible reduction in SINAD will occur.

None of this banter about noise with shared PSUs or running somewhat hot (yet WELL within acceptable parameters) is dulling my enthusiasm at least. ¯\_(ツ)_/¯

-Ed

 

[Miser_Audioman]

For 200 bucks, it seems like a fun opportunity to experiment, test, listen. I pledged. See if they sound good, see if they let the smoke out. I will hook these up to an old Yamaha RX V630 to drive old Paradigm monitor 7 v3s. The gain should help with the lower volt pre-out (i think).

I’ve been out of the hobby in any serious way for nearly 20 years and really enjoying Amir and ASR to get reoriented and updated. Thanks everyone!

 

[SMen]

Really…although the short story really seems to be that if you just use separate power supplies, it will sound great, even single-ended, where an imperceptible reduction in SINAD will occur.

None of this banter about noise with shared PSUs or running somewhat hot (yet WELL within acceptable parameters) is dulling my enthusiasm at least. ¯\_(ツ)_/¯

-Ed

Yes. I'm seriously looking forward to trying mine with just one, noise and problem free 48v 10A power supply

 

[sl1982]

I am interested to see if there is any additional headroom in these if we hook only one up to a 10A power supply. If thats the case ill add another power supply to my kickstarter.

 

[Great Sun Jester]

Strange to think how may this be possible that they didn’t find it in their product before sending it to so called youtube influencers.
What happened to internal testing and all!

Inexplicable.

 

[Guddu]

Inexplicable.

pre-production unit is also a finished product after all, and is subject to testing.
At the end of the day, if this is helping buyers to get a problem free product for their money then let’s keep it coming else it’s all good.

 

[TonyJZX]

it used to be saleable products first off the production line AFTER all teething and QA QC issues are sorted

 

[iLoveCats]

I thought Fosi stated the noise issue is only if you use one mono amp off the Y cable at one time. Nobody would use it like that, there's no real world use case for this. Fosi also said they would fix it or send 2 power supplies. When I bring on new equipment, I ALWAYS think I thought of everything, and I never did. I deal with this constantly at work in oil/gas.

 

[Overseas]

Check MVP - minimum viable product.

 

[Guddu]

I thought Fosi stated the noise issue is only if you use one mono amp off the Y cable at one time. Nobody would use it like that, there's no real world use case for this. Fosi also said they would fix it or send 2 power supplies. When I bring on new equipment, I ALWAYS think I thought of everything, and I never did. I deal with this constantly at work in oil/gas.

Interesting that many measurements and tests are still there even though those aren’t practical in real world used case, its a big debatable topic here on ASR but I am not going there.
Appreciate what you said but IT change management process made me learn the need of testing in every way possible, every possible issues if possible.
You never know how creative a user could be using what they buy .

PE. and that’s where disclaimers can help, like if you are buying one psu to power up 2 amplifier units then “xyz” is expected……..

 

[totti1965]

@amirm : Will there be also a test of the serial version which will be out at the beginning of June?
It would be interesting to see the max. Version of the power supplies, according to kickstarter 2 x 48 Volt 10 A, which is new record for on chip amps! Can it squeeze even more power out of these tiny things?
If there will be another test, it would be totally interesting to see switching frequency in a test which runs up to 1,2 MHz, and how good it is suppressed.
Sorry, in case if anybody has asked these things before. I can’t read the whole thread.

Thorsten

 

[SMen]

I thought Fosi stated the noise issue is only if you use one mono amp off the Y cable at one time. Nobody would use it like that, there's no real world use case for this. Fosi also said they would fix it or send 2 power supplies. When I bring on new equipment, I ALWAYS think I thought of everything, and I never did. I deal with this constantly at work in oil/gas.

Interesting that many measurements and tests are still there even though those aren’t practical in real world used case, its a big debatable topic here on ASR but I am not going there.
Appreciate what you said but IT change management process made me learn the need of testing in every way possible, every possible issues if possible.
You never know how creative a user could be using what they buy .

PE. and that’s where disclaimers can help, like if you are buying one psu to power up 2 amplifier units then “xyz” is expected……..

Exactly. Sounds like earthing issue when one of the units is turned off, and the other is on, but both units are connected with the Y cable.
Disclaimer a good idea.
I remember having buzzing turning off a valve amplifier as the power supply 'drained' for it to be fully "off". Apologies for the non technical description. No noise when it was on.

 

[TheBatsEar]

How do you guys control volume with these monoblocks?

You control it at the source or use a pre amplifier. I for one use a MiniDSP Flex, it has a volume knob and a remote, acting as a pre amplifier for all connected sources (TV, CD, Computer). I also have a Wiim Pro Plus that can do the same. I had a Topping E30 that could do volume as well.

Will there be also a test of the serial version which will be out at the beginning of June?

Unlikely. It's just another chip amp and soon other things will capture our focus.

 

[Yorkshire Mouth]

Sorry if I’ve missed this.

Comments on the gain switch appear to be ubiquitously vague. “Depending on your source…”. Excuse me? Depending on what specifically?

Would anyone care to elaborate?

 

[Deleted member 72219]

Sorry if I’ve missed this.

Comments on the gain switch appear to be ubiquitously vague. “Depending on your source…”. Excuse me? Depending on what specifically?

Would anyone care to elaborate?

Different sources will have different starting gain levels, so the amount of gain at the power amp should vary as well to balance things out. My multimode preamp, for example, has a passive mode and a unity gain solid state buffer mode, but the tube buffer mode has a big gain, it’s nice to have only 20db gain on the balanced input of the V3 Mono since I do my critical listening in tube buffer mode. Granted, when using solid state buffer mode, I will simply turn the volume up on my preamp to compensate for background/casual listening, but in those situations, I don’t tend to raise the volume as high as I do in critical listening anyway.

-Ed

 

[ninetylol]

You control it at the source or use a pre amplifier. I for one use a MiniDSP Flex, it has a volume knob and a remote, acting as a pre amplifier for all connected sources (TV, CD, Computer). I also have a Wiim Pro Plus that can do the same. I had a Topping E30 that could do volume as Well.

I have a WiiM too, but just in case the device resets itself or something else bad happens, you suddenly blow your speakers up with so much watts.