Fosi Audio V3 Amplifier Review

[OldTimer]

Does Fosi V3 (with Fosi 48V PSU) make anyone’s system sound … heavy and ‘boomy’? It does with my DBR62.

That’s my very first impression. As if the amp was ‘forcing’ the power/sound. Seems a bit ‘muddy’, and instrument separation not very clear.

Maybe I’ve got a faulty unit or doing something wrong? Maybe the new amp needs more hours/days?
On Monday I might have some time for proper testing, but atm the impression is, Aiyima a07 (w/ stock 32V PSU) doesn’t sound as ‘heavy’.

Right now I’ve got one speaker connected to V3 and one to A07, and reconnect the DAC between them. Might get a RCA Splitter (or my old mixer running) and banana plugs for better testing.
I’d also welcome good songs in mono to test the pairing (as I’m using 1 speaker per amp). Really curious …

Tidal HiFi -> Wiim Mini -> Topping E50 -> Fosi V3 - Elac DBR62.

My Wharfedale speakers are happier than using $500 amp japanese brand. Probably Elac doesn’t like the amp.

 

[hifi72]

Would this drive a pair of Revel M16s in a small-medium room (5m x 3m)?

Thanks.

I have the same question as well, hopefully someone has tried the pairing and can comment.

 

[Mai.live.in.Tokyo]

I have the same question as well, hopefully someone has tried the pairing and can comment.

I use it with a pair of B&W 603 towers and it is amazing. The B&W are notoriously power hungry and this little beast just laughs and says, "Hold my beer."

 

[G-Can]

so, Im not sure when this started happening, but lets say now, when Im skipping through ytb video, speakers make little pop everytime, like a quick crunch.
at any volume.
I have SMSL C100 DAC + V3 connected to PC via USB.

what is happening? I could bet money that this started happening recently

 

[OldTimer]

so, Im not sure when this started happening, but lets say now, when Im skipping through ytb video, speakers make little pop everytime, like a quick crunch.
at any volume.
I have SMSL C100 DAC + V3 connected to PC via USB.

what is happening? I could bet money that this started happening recently

How long have you been using it, before making little pop recently?

 

[G-Can]

How long have you been using it, before making little pop recently?

I wanna say 2 months or so

 

[OldTimer]

I wanna say 2 months or so

So, it means I have to prepare after 2 months. I just used it today.

 

[G-Can]

So, it means I have to prepare after 2 months. I just used it today.

I wouldnt stress about it, this might as well be a software issue though, and the fact I actually put larger speakers on it so that might be trigering it as well.

 

[CauliflowerEars]

You could use something like this.
Amazon.com

Thank you, have you used one of those before? Just got one today, but there is no manual.
I don't want to fry anything, so would like to double check, is the following assumption is correct?

Switch position 1:
Amp 1:
* Connect both cables of the Left speaker output to 5.
* Connect both cables of the Right speaker output to 1.
Speakers:
* Connect both Left speaker cables to 6.
* Connect both Right speaker cables to 2.

Switch position 2
Amp 2:
* Connect both cables of the Left speaker output to 7.
* Connect both cables of the Right speaker output to 3.
Speakers:
* Connect both Left speaker cables to 8.
* Connect both Right speaker cables to 4.

So, speakers would need to have 4 cables (2 sets of 2 cables) coming out of the binding posts?
One set for amp 1, the other set for amp 2?

BTW, with the V3 48V, I think it might have been an issue with the PSU. Right now the amp isn't as heavy and boomy.
Maybe the PSU behaves differently after being in below freezing temperature for a long delivery time?

 

[bbjayo]

So, what's your verdict?

Sold the A07

 

[hifi72]

I use it with a pair of B&W 603 towers and it is amazing. The B&W are notoriously power hungry and this little beast just laughs and says, "Hold my beer."

Awesome. Did you go for the 48V supply or stock? I’m about to order one. If you did go 48V, I see two options now for the 48V regular plus 48V GaN?.

 

[Mai.live.in.Tokyo]

Awesome. Did you go for the 48V supply or stock? I’m about to order one. If you did go 48V, I see two options now for the 48V regular plus 48V GaN?.

I grabbed the 48V but not the GAN version, juts the normal 48V. Really wanted to give the amp as much chance against these power hungry beasts and it stepped right up and punched them right on the chin and swaggered. Such a great pairing.

 

[hifi72]

I grabbed the 48V but not the GAN version, juts the normal 48V. Really wanted to give the amp as much chance against these power hungry beasts and it stepped right up and punched them right on the chin and swaggered. Such a great pairing.

Nice. Sounds good. No speakers or preamp here yet but this looks like a good spot to start.

 

[SoonToBeRetired]

I hope I did the right thing. I just bought one of these things with the 48V power supply to run my very inefficient but beautiful to look at Polk LsI9's which have been languishing in a closet. Do you think I'm being too optimistic? This "load dependence" concept is too complicated for me to grasp with my limited knowledge. It was certainly a bargain, though. The price was dropping as I put it in the "cart".

 

[G-Can]

I hope I did the right thing. I just bought one of these things with the 48V power supply to run my very inefficient but beautiful to look at Polk LsI9's which have been languishing in a closet. Do you think I'm being too optimistic? This "load dependence" concept is too complicated for me to grasp with my limited knowledge. It was certainly a bargain, though. The price was dropping as I put it in the "cart".

for normal volume listening you should be okay.

 

[asimze]

Put post filter feedback in it, and pretty much all that load dependency vanishes.

How to do it?

 

[antcollinet]

How to do it?

That is a job primarily for the manufacturer. Not a mod that many people are going to be up to.

 

[OldTimer]

That is a job primarily for the manufacturer. Not a mod that many people are going to be up to.

It will add the price

 

[asimze]

That is a job primarily for the manufacturer. Not a mod that many people are going to be up to.

I think correctly is to say what to do, technical informatin. How to do it is other problem.

 

[antcollinet]

It will add the price

A little - but not much. It will be consist of a few resistors and capacitors, plus perhaps an op amp or two, and might just replace the ones in the pre filter feedback. The main difficulty is the control theory understanding to make it work properly. But that is a design effort/knowhow thing.