Fosi v3 Mono - User Impressions | Owner's Thread

[SMen]

Following on / being more specific ... how audibly better are some of the more expensive class D amps ... subjectively ... is not such a dangerous question here because the question is : how audible are the better measurements of say the Hypex at 3x the price, or Purify at 5x.

For me the Monos, with digital and phono balanced sources, and excellent balanced volume control are much better than say the Aiyimas (A07, A08) that I have.
Just greater sense of both resolution and control - but they (the monos) measure better also.
This gives me a feel for the measurements up to the level of the Fosi Monos ... but not "higher" ...

 

[Giro413]

just unplug all inputs and leave Wiim with wifi connection into your amp .... and let us know hit it behaves

I did this for a couple of days and it does seem that unplugging my turntable removes the problem. Hopefully grounding the turntable (which the WiiM Ultra will allow) will fix it.

 

[Sokel]

Something isn't better if it's more then 50% costlier. it is better and costlier, but not better

@NTK: the definition of virtual benefits in two pics

Spoiler

for only 400 bucks!

For about $450 you get this:


instead of this:



You don't even have to open the pics,is visible just with the thumbnails and hypex has a healthy 5dB more gain which always gives a penalty in measurements,so it would be even better at 20dB gain as the fosi instead of it's 25dB.
You also get a tested amp,decent tested protections for your speakers,ease of transaction,etc

If the modding price even remotely approach the former,well...

To make it even worst,I have no dog in that race,only common sense,some ability to read measurements,look at thermals,etc and a way to roughly measure stuff for sanity,so no fanboi at either camp.

I would also expect a member of a technical site to distinguish what's technically better or not.

 

[Negatywny]

I would also expect a member of a technical site to distinguish what's technically better or not.

like i already said, because we are on a technical site - i'm not interested in whats technically better (16 core processors) but what cost effectively does it's task (two core processors). And sorry to say that, but 2,5 times overpaying for 0,5 db at 20khz or other inaudible differences isn't better. Call me when for 200$ i'll get something better.

 

[Sokel]

like i already said, because we are on a technical site - i'm not interested in whats technically better (16 core processors) but what cost effectively does it's task (two core processors). And sorry to say that, but 2,5 times overpaying for 0,5 db at 20khz or other inaudible differences isn't better. Call me when for 200$ i'll get something better.

???
$260 to $399,17 € tax excl (or 450 incl. ) is 2.5 times?

As far as I have seen in ths thread is just a couple of (low) fancy op-amps away

Yep,I'm done with that silly stuff.

 

[ScofieldKid]

Ah, Home Assistant. I see the same for my two amps (10W per amp during normal operation) at normal listening volume. I‘ve been using the setup for three days and this was the first time it happened. So, this is something that happens only occasionally.

The challenge in my case is that the circuit breaker got triggered so fast that no telemetry was sent to my MQTT instance, so I don‘t have additional data.

For the moment I have changed the setup so that one of the V3Monos is turned on with a slight delay. I‘m curious whether this approach fixes the problem, but also whether others have the problem also.

Cheers, Joachim

If you happen to see a Roland RLC-900 for sale used cheap somewhere, that might help you. I've used one of those for years on one of my amps to achieve delayed start. Otherwise, welcome to old-school, where you manually engage power-on and power-off sequencing with your bare hands. It's "the cowboy way!"

 

[Negatywny]

???
$260 to $399,17 € tax excl (or 450 incl. ) is 2.5 times?

oh grate comparison, you got me, now try with monoblocks xD

 

[Sokel]

oh grate comparison, you got me, now try with monoblocks xD

14cm x 10cm monoblocks
Yep,I'm so done,don't even try.

 

[EddNog]

14cm x 10cm monoblocks
Yep,I'm so done,don't even try.

This discussion was over the moment he decided that what he was ACTUALLY asking for was a better value, not just better (performing). His concept of the simple phrase, “better,” is incongruous to ours. Don’t waste any more time or effort on him.

-Ed

 

[Sokel]

This discussion was over the moment he decided that what he was ACTUALLY asking for was a better value, not just better (performing). His concept of the simple phrase, “better,” is incongruous to ours. Don’t waste any more time or effort on him.

-Ed

Even value is debatable as it should be considered over time.
And at the time being we have no idea of the longevity of this ones.
But it's thermals are not exactly reassuring.
We'll see.

 

[Negatywny]

This discussion was over the moment he decided that what he was ACTUALLY asking for was a better value, not just better (performing). His concept of the simple phrase, “better,” is incongruous to ours.

yes it is
You are those people who when asked if there is something better than the 13th generation Core i3 answer that of course there is - Core i9, and you are proud of yourself xD

 

[EddNog]

Even value is debatable as it should be considered over time.
And at the time being we have no idea of the longevity of this ones.
But it's thermals are not exactly reassuring.
We'll see.

Preaching to the choir here. I very much had my eye on a Purifi-based amp, or even pair of monobloc amps, but decided against it in the end for various reasons—performance, however, was not one of them.

-Ed

 

[DudeAnon]

the example you gave is literally the definition of no benefit. A similar situation occurs when you can buy a 16-core processor to play games that support two cores. Is this processor better? Theoretically yes, practically no. So my definition is if something is practically better and not virtually better, not very trolling but very rational.

No, it’s better, but may not be worth it to you.

 

[Guddu]

Don’t know if anyone has shared thermal scans in this thread but this is from Fosi’s FB.

 

[Sokel]

View attachment 385402

Don’t know if anyone has shared thermal scans in this thread but this is from Fosi’s FB.

Stacking them on top of each other as if they didn't had thermal limitations already

Has anyone measured the temps of the PSU under stress?
That is sure important,specially if they are hidden somewhere without plenty of ventilation.

 

[norcalscott]

I received my pair of amps and a single power supply with the splitter and filter a couple of weeks ago, but just got the time to play around with them in the last week. I replaced an SMSL AO200 amp that I have been using with an SMSL SU-9 for a couple of years to drive my Wharfedale Linton's. It's been an enjoyable system that I have used a lot in my main listening room - very clean, but maybe just slightly lacking in power although I normally ran them at 60-70%.

Comparing the Fosi V3's, they seem just as clean and distortion free as the AO200 but a little more powerful and with noticeably possibly, maybe, maybe not better channel separation. I moved my subwoofer to a different location in the room and that improved the low end.

I mostly drive my system with a Windows laptop and Tidal, or Foobar2000 to play my collection of FLACs (or older MP3s). I am extremely happy with the sound and performance of my new setup with the Fosi's. I'm not going to try and discuss any subjective feelings about the sound, but these amps drive my speakers well and I feel like it is a worthwhile (if not dramatic) upgrade from the AO200.

Regarding the running temperature - I was surprised how hot these little buggers get when you really drive them - almost to the point of uncomfortable to the touch. I had a couple of AC Infinity USB powered fans laying around (these have been mentioned in other posts here) but I didn't want to put them under the amps, so I tried setting them on top, with the airflow going up, away from the amps. This made a huge difference in running temperature. I haven't measured it yet, but I would estimate they run 50% or more cooler with these fans drawing air away from the amps.

Great job Fosi with these amps!

 

[Killingbeans]

Comparing the Fosi V3's, they seem just as clean and distortion free as the AO200 but a little more powerful and with noticeably better channel separation.

The specs of the SMSL AO200 says its channel separation is 98dB. Can you seriously hear an improvement on that?

 

[antcollinet]

The specs of the SMSL AO200 says its channel separation is 98dB. Can you seriously hear an improvement on that?

Yeah - I raised my eyebrows at that comment also.

 

[norcalscott]

The specs of the SMSL AO200 says its channel separation is 98dB. Can you seriously hear an improvement on that?

Probably not, just giving my impression in this user impression thread

 

[norcalscott]

Yeah - I raised my eyebrows at that comment also.

Truth be told, my old ears don't hear much difference with these and my other amp (other than a little more power) - which is really a testament to the value of these Fosi amps. I only bought them out of curiosity and the fact that the Kickstarter pricing seemed to be a good deal. They will warm the room in winter a little better than the AO200, that's for sure.