Fosi Audio V3 Mono Amplifier Review

[early rejecter]

Converting from balanced to single-ended can easily be done passively. You can use the 4.4mm balanced out to subwoofer with this:

EDIT: You will also need to add some sort of in-line attenuator or volume dial to cut the signal down as I just realized your 4.4mm output is amplified, not line level.

Assuming he’s sticking with the iFi Zen, is there any reason to not just use RCA splitters to send the signal from the pre-amp to both the amps and subwoofer? That’s what I’ve always done with my pre-amps that don’t have dedicated subwoofer output.

 

[EddNog]

Assuming he’s sticking with the iFi Zen, is there any reason to not just use RCA splitters to send the signal from the pre-amp to both the amps and subwoofer? That’s what I’ve always done with my pre-amps that don’t have dedicated subwoofer output.

I actually am not aware of a reason other than is there a potential voltage drop for each of the post-split outputs? If not then this works too.

-Ed

 

[rvsixer]

I was afraid of that. Hypex is unfortunately out of my budget right now. Do you think the v3 monos would at least be better than a middle range AVR driving these?

These will put out much more power than most any budget/midrange receiver (especially with all channels driven). Call me counter, but given the Fosi's excellent 2-ohm performance (including resistive and capacitive loads), I'd have no problem giving them a go (and I will myself, as soon as Fosi answers to the 10A power supply peculiarities).

 

[sl1982]

These will put out much more power than most any budget/midrange receiver (especially with all channels driven). Call me counter, but given the Fosi's excellent 2-ohm performance (including resistive and capacitive loads), I'd have no problem giving them a go (and I will myself, as soon as Fosi answers to the 10A power supply peculiarities).

Worth a shot then. I was planning on ordering a 2nd 10A power supply and running each of them on their own.

 

[SMen]

Worth a shot then. I was planning on ordering a 2nd 10A power supply and running each of them on their own.

My problem with this is the price. The 48v "10A" is quite expensive. Aiyima's is much less and seems to be genuine. Not sure we should be 'encouraged' to double up just because the power supply is not as described. Fosi may have tested "a" 48volt 10a supply, but we need "the" 48volt 10a supply to be 48v10a. It should be easy to clear this up though.

 

[sl1982]

My problem with this is the price. The 48v "10A" is quite expensive. Aiyima's is much less and seems to be genuine. Not sure we should be 'encouraged' to double up just because the power supply is not as described. Fosi may have tested "a" 48volt 10a supply, but we need "the" 48volt 10a supply to be 48v10a. It should be easy to clear this up though.

I agree with this. Right now what I end up getting depends on what they say on their 10A supplies. Maybe just get two bare amps and get the supplies seperate

 

[Kayshot]

On the power supply subject, I read into the debacle over the 10a option so I just changed my pledge to the package with two amps and two 5a power supplies.
It runs the same price as two amps with one 10a supply. Only mentioning this in case some people think they are stuck with their original pick.

 

[EddNog]

On the power supply subject, I read into the debacle over the 10a option so I just changed my pledge to the package with two amps and two 5a power supplies.
It runs the same price as two amps with one 10a supply. Only mentioning this in case some people think they are stuck with their original pick.

For people who were one of the first 200, will they forfeit their 30% discount if they switch now? I imagine yes.

-Ed

 

[Kayshot]

For people who were one of the first 200, will they forfeit their 30% discount if they switch now? I imagine yes.

-Ed

I'd assume so, but the discount is still 25% (at least for me, not sure if that tracks with my original pledge-date).

5% of an already budget-option seems like it wouldn't be a deciding factor for most people here, but who knows!

 

[Negatywny]

this pro knobs look pretty interesting, could provide temporary solution...

PreSonus | Wherever sound takes you.

Studio One software, studio monitors, digital audio interfaces, mixers, microphones, preamps, pad controllers, control surfaces, and more.

www.presonus.com

this one with sub and headphones out (and blutooth) and pretty decent S/N 102dB - add 2-3 rca inputs and remote control and it would be almost perfect...

 

[MCH]

intersting.
Top: this ebay listing https://www.ebay.co.uk/itm/275540643117
Bottom: Guddu's review here in ASR:
most (all?) huntkey models, the three figures after the letters denote power in watts

have seen worse made though :

 

[Sokel]

intersting.
Top: this ebay listing https://www.ebay.co.uk/itm/275540643117
Bottom: Guddu's review here in ASR:
most (all?) huntkey models, the three figures after the letters denote power in watts

View attachment 366964

I think a simple calc is enough:

 

[spandy]

Seems like it's time for @Fosi Audio to chime in and clear this up. I hope there is a 10a variant of that same psu that they've elected rather than the 6.25A version shown here.

 

[Sokel]

Seems like it's time for @Fosi Audio to chime in and clear this up. I hope there is a 10a variant of that same psu that they've elected rather than the 6.25A version shown here.

Huntkey does not even list the one shown in their industrial adapters.
I hope it's a custom version,for the friends who choose this amp.

As is I would take two 5A ones (or two 10A or whatever they are) over the one listed for 10A.

 

[Psinet]

now that is an oxymoron!

Bomb-proof construction, Duratex coated, mobile usage, but high-end hifi componentry.

 

[GoDawgs]

Assuming he’s sticking with the iFi Zen, is there any reason to not just use RCA splitters to send the signal from the pre-amp to both the amps and subwoofer? That’s what I’ve always done with my pre-amps that don’t have dedicated subwoofer output.

I actually am not aware of a reason other than is there a potential voltage drop for each of the post-split outputs? If not then this works too.

-Ed

I've believe I'm going to try the Elac Sub 1010 subwoofer: 10"driver, 120W peak, 60W RMS, inputs: L/R/LFE/speaker level. I'll use my IFI Zen DAC/AMP (in variable mode for volume control), split off the RCA cords for the sub woofer from the rear balanced 4.4mm output from the Zen as Early Rejecter suggested and then use the two mono blocks to power my passive 6 ohm bookshelf speakers. (I hope...)

On the power supply subject, I read into the debacle over the 10a option so I just changed my pledge to the package with two amps and two 5a power supplies.
It runs the same price as two amps with one 10a supply. Only mentioning this in case some people think they are stuck with their original pick.

I did order the two 5amp power supplies after seeing a YouTube video where the reviewer claimed he heard some noise using the supplied 10amp power supply with the splitter cable for both mono amps. It was exactly the same price for two 5amp power supplies, I went for that, what I hope turns to be the safer decision. Thanks EddNog and Early Rejecter for your help! This forum is a grand find and a treasure trove of info. Some of us aren't as knowledgeable as others but, being just eye candy isn't ALL bad.

 

[Guddu]

The technical improvement is notable, but unless you have speakers with a particularly critical impedance curve, you will hardly hear a difference in everyday use.
If you don't hear any noise, if there's enough power, and if you don't perceive an altered frequency response with your A07, the gearbox isn't very useful.

And to add, normally you would use calibration on your avr in HT setup which should take care of any frequency or timing correction needed.

 

[Nahkarankaisija]

I have found a used Pro-Ject Pre Box DS2 Analog for 250€, I would pair this with the two Fosis and use my SMSL SU-6 DAC to connect it to my PC, the preamp would be used for volume control and the DAC would be set at 0db volume, in my mind I don't see any negatives to this setup except for perhaps a longer signal chain with 3 separates but it should be a reliable and easily upgradeable setup. Any thoughts? Main point would be the purely analogue volume control of the Pro-Ject.

 

[Negatywny]

no xlr, expensive but not fancy

 

[gwing]

Seems like it's time for @Fosi Audio to chime in and clear this up. I hope there is a 10a variant of that same psu that they've elected rather than the 6.25A version shown here.

Yes, I hope so to0 - but I'm going to stick with the 10/6.5A version anyway. I'm not likely to drive them hard enough for it to be a problem, and if that usage changes I'm happy to just get another 10A of some description.