Fosi Audio V3 Mono Amplifier Review

[Rafaille]

I have a basic math question about power.

I got the 10 amp version and using with a Wiim Ultra into 4ohm speakers. The Wiim puts out 2Vrms and the Fosi has a ~2.4Vrms input sensitivity at 4ohm.

Amir measured the Fosi output at 4 ohms in the 230 Watts range. If I have the Wiim at full 100 / 2Vrms the Fosi should be delivering around (2/2.4)*240 or 200w? Is that approximately and conceptually right?

Is the input sensitivity really above 2Vrms with RCA? I thought it was ~1.6Vrms.

 

[MickeyBoy]

I'm beginning to feel like your father (old) ... I can happily hit 80db ... but I'm surprised how much of my listening that I thought was loud, is actually down in the 70dbs.

View attachment 388671

I use one of these great little gadgets. Set it to max and you get a fixed value for the duration it is set to max.

Nobody talks about balance these days. Even digital recordings or broadcasts in digital can somehow get the balance wrong. Old ears (or indeed young) have imbalance.

Or whoever is in the studio handling the mix!

I wish whoever it is in the BBC studio doing the mix would get their ears tested for the sports commentary ...

Okay I appreciate that this is going to be lost on many here ... but the snooker commentary at the Crucible was much better this year ...

The "Today at the Test" cricket commentary (currently) is 1 to 1.5 db off to the right!

So what's the point of separate power supplies, and wonderful channel separation with monoblocks ... if you can't adjust the balance because someone can't hear properly in the mixing studio!

Or maybe it is just me...

What is that gorgeous little gadget?

 

[SMen]

What is that gorgeous little gadget?

It's a very cheap but effective little hand held db meter to let you know when you are listening too loud (or quieter than you think)!

Run a search on ali express or elsewhere for "FY8862 Sound Level Meter" for the best price. Not expensive.

 

[EddNog]

I'm beginning to feel like your father (old) ... I can happily hit 80db ... but I'm surprised how much of my listening that I thought was loud, is actually down in the 70dbs.

View attachment 388671

I use one of these great little gadgets. Set it to max and you get a fixed value for the duration it is set to max.

Nobody talks about balance these days. Even digital recordings or broadcasts in digital can somehow get the balance wrong. Old ears (or indeed young) have imbalance.

Or whoever is in the studio handling the mix!

I wish whoever it is in the BBC studio doing the mix would get their ears tested for the sports commentary ...

Okay I appreciate that this is going to be lost on many here ... but the snooker commentary at the Crucible was much better this year ...

The "Today at the Test" cricket commentary (currently) is 1 to 1.5 db off to the right!

So what's the point of separate power supplies, and wonderful channel separation with monoblocks ... if you can't adjust the balance because someone can't hear properly in the mixing studio!

Or maybe it is just me...

With regards to balance, as long as the vocalist in the vast majority of recordings is centered, I leave it alone. From a practical standpoint, I already find that a lot of recordings don't have balanced left/right sound primarily just because of studio/stage layout. You have a percussionist on the right side (stage left) and he's just banging out a rhythm nonstop, but then you have some other person on the opposite side of the stage hitting a triangle like 3 times in a song, and now your recording is heavily right-speaker loaded. This kind of recording imbalance is completely the norm for so many songs that I just let balance go now, like I said, so long as the vocalist remains dead center most of the time (the recordings where the lead singer is off-center really throw me!). Chesky Records has a system setup album with a stereo imaging test and that one is great for making sure your system is properly set up left/right balanced (especially useful for listening rooms that are not symmetrical, like mine).

-Ed

 

[antcollinet]

Is the input sensitivity really above 2Vrms with RCA? I thought it was ~1.6Vrms.

For 230W into 4 ohm, you need 30V output from the amp.

Gain is 25.5dB (low setting) = x18.8, so 30V would need just under 1.6V, so you are correct - there is no power limitation with 2V into the amp.

Gain on XLR is 20.5, which would need 2.83 input volts for 230W, so I'm not sure where @Mort got the 2.4V requirement from.

 

[Mort]

For 230W into 4 ohm, you need 30V output from the amp.

Gain is 25.5dB (low setting) = x18.8, so 30V would need just under 1.6V, so you are correct - there is no power limitation with 2V into the amp.

Gain on XLR is 20.5, which would need 2.83 input volts for 230W, so I'm not sure where @Mort got the 2.4V requirement from.

Apologies. I thought I got that from the reviews. I was more concerned about the formula in my question.

 

[antcollinet]

Apologies. I thought I got that from the reviews. I was more concerned about the formula in my question.

No need to apologise. I wasn't having a go. I only mentioned you so you would know you don't have an issue to worry about.

 

[Erikson]

Hello all. New member here but have been reading along for a long time and I love ASR.

I'm planning to set up a system with two V3 monos and a WIIM Pro+ as a preamp. The auto mode of the V3 is of course great only ... I only want to use the system for a few hours a day and then maybe not even every day so power consumption at rest might be a bit high then. I thought how can I still get it more efficient and thought that maybe I could use the trigger out of the WIIM to switch a trigger powerstrip. I couldn't really find such a socket but is it at all a good idea to turn the V3 mono'on this way? Anybody any ideas on this?

einde bewerkbare sectie
he
Hallo allemaal. Nieuw lid hier, maar ik lees al een tijdje mee en ik hou van ASR.

Ik ben van plan om een systeem op te zetten met twee V3 mono's en een WIIM Pro+ als voorversterker. De automodus van de V3 is natuurlijk geweldig, maar ... Ik wil het systeem maar een paar uur per dag gebruiken en misschien zelfs niet elke dag, dus het stroomverbruik in rust kan dan wat hoog zijn. Ik dacht hoe kan ik het nog efficiënter krijgen en dacht dat ik misschien de trigger-uitgang van de WIIM kon gebruiken om een trigger-stekkerdoos te schakelen. Ik kon zo'n socket niet echt vinden, maar is het überhaupt een goed idee om de V3 mono op deze manier aan te zetten? Iemand ideeën hierover?

einde bewerkbare sectie

 

[antcollinet]

Hello all. New member here but have been reading along for a long time and I love ASR.

I'm planning to set up a system with two V3 monos and a WIIM Pro+ as a preamp. The auto mode of the V3 is of course great only ... I only want to use the system for a few hours a day and then maybe not even every day so power consumption at rest might be a bit high then. I thought how can I still get it more efficient and thought that maybe I could use the trigger out of the WIIM to switch a trigger powerstrip. I couldn't really find such a socket but is it at all a good idea to turn the V3 mono'on this way? Anybody any ideas on this?

einde bewerkbare sectie
he
Hallo allemaal. Nieuw lid hier, maar ik lees al een tijdje mee en ik hou van ASR.

Ik ben van plan om een systeem op te zetten met twee V3 mono's en een WIIM Pro+ als voorversterker. De automodus van de V3 is natuurlijk geweldig, maar ... Ik wil het systeem maar een paar uur per dag gebruiken en misschien zelfs niet elke dag, dus het stroomverbruik in rust kan dan wat hoog zijn. Ik dacht hoe kan ik het nog efficiënter krijgen en dacht dat ik misschien de trigger-uitgang van de WIIM kon gebruiken om een trigger-stekkerdoos te schakelen. Ik kon zo'n socket niet echt vinden, maar is het überhaupt een goed idee om de V3 mono op deze manier aan te zetten? Iemand ideeën hierover?

einde bewerkbare sectie

I turn all my gear on and off at least once a day using a wifi power socket. I just shout at Alexa to do it for me, no trigger interface required. If I had v3 Monos, I'd do the same with them.

 

[EddNog]

I turn all my gear on and off at least once a day using a wifi power socket. I just shout at Alexa to do it for me, no trigger interface required. If I had v3 Monos, I'd do the same with them.

That’s…smart.

*Badum-tisssssssss*

 

[Mort]

Mine pop when switched on from off and the power remains connected. There is No pop on auto while it remains powered. (Also have minor pop XLR to RCA).

Is there pop when you send power via smartswitch and it's already set on auto?

 

[Erikson]

I turn all my gear on and off at least once a day using a wifi power socket. I just shout at Alexa to do it for me, no trigger interface required. If I had v3 Monos, I'd do the same with them.

ocket. I just shout at Alexa to do it for me, no trigger interface required. If I had v3 Monos, I'd do the same with them.

I turn all my gear on and off at least once a day using a wifi power socket. I just shout at Alexa to do it for me, no trigger interface required. If I had v3 Monos, I'd do the same with them.

ok thanks. I can work with my Google Home but if i can find a trigger powerstrip it wil work realy smart, smile. I don’t know it is not bad to turn on the system on this way. I will use two 5a bricks.

 

[galego100]

I must have clouds above my head... Now @Fosi Audio on September 3 , send me , new package, to replace the first one from Kickstarter, which was detained by Spanish customs... Now since September 3 , the tracking shows no move , update, life, or something else!!

Since September 3, the track shows , "Your package is waiting to be picked up by the carrier" "Shipment information received" , still on China...

 

[ninetylol]

Shipping from China may take its time, I think they usually collect packages over few days which then all get shipped via ship.

 

[burkm]

@galego100
Did You contact Fosi Audio already, confronting them with that status message You got ?
Strange, that the new delivery is still at the factory.

Note: My experiences considering "delivery" are: Did You check with them, because if I remember faintly, they might have currently run out of V3 Monos and are waiting for the next charge of V3 Monos to be delivered to their premises (warehouse). This might take some time because of i.e. retooling for that known "phase inversion" issue...
Many companies "manage" shipments also: They get a delivery label online (data) as soon as they get "Your order" or the delivery is (re-)enabled but the item will then be physically delivered only as soon as it is "really" ready (or available) for delivery.
"Patience" might be asked for now (again)...

 

[galego100]

@galego100
Did You contact Fosi Audio already, confronting them with that status message You got ?
Strange, that the new delivery is still at the factory.
My experiences considering "delivery" are: Did You check with them, because if I remember faintly, they have run out of V3 Monos and are waiting for the next charge of V3 Monos to be delivered to their premises (warehouse). This might take some time because of i.e. retooling for that known "phase inversion" issue...
Many companies "manage" shipments also: They get a delivery label online as soon as they get "Your order" or the delivery is (re-)enabled but the item will be physically delivered only as soon as it is "really" ready (or available) for delivery...

I contact them , and Jocelyn and told me , on September 4, "
We have re-sent you the products, please check the tracking link below:"

After that , 2 days ago i contact them for some news , and no answer, nothing...

 

[burkm]

She probably did, what she was told, and read it of the screen and didn't tell You that there are no V3 Monos in the warehouse right now...

 

[Karlaka]

Dear friend Galego. You're really out of luck. But anyway, just as I imagined, FOSI is responding. The mere fact of sending you a new pair of amplifiers speaks highly of them. when I consider that they have no responsibility for the bureaucracy of Spanish customs and its possible obstacles. I sincerely hope you can be reunited with your equipment soon.
Greetings!

 

[kingkoolkris]

Mine arrived yesterday (Double pack with 10A PSU) and they're working flawlessly. They're getting pretty warm but nothing concerning I'd think.
They're hooked up to my Onkyo TX-RZ730 RCA preouts.

 

[Brian Hall]

Mine arrived yesterday (Double pack with 10A PSU) and they're working flawlessly. They're getting pretty warm but nothing concerning I'd think.

Winter is coming. The extra warmth might be nice.