Fosi Audio V3 Mono Amplifier Review

[tomtoo]

Yes, but it is much more like a morbid curiosity to see how long it will take to destroy itself, without any real value. Clearly that little guy isn't designed to deliver 300 watts continuously at 2 ohms, but the mere fact that it can briefly deliver that power under such a harsh load is in itself absolutely exceptional. It seems like unnecessary cruelty to me

Not cruel, it will go into thermal protection. At least it should, and i thrust the tpa.

If you like to build your own active system its very interesting how long the amp can deliver power. Imagine some 2 ohm homecinema subs. There is also a trend for 2 ohm (high current) speakers in hifi.(not say its good or bad). From my point of view its interesting how long a amp can stay max. power.

 

[tomtoo]

I like to know the limits too but this 2 Ohms sine wave stress test is a destructive test.

Should go into protection.

 

[Doodski]

Should go into protection.

Any idea what the 2 Ohms test parameters are that @amirm used for the various phase relationship 2 Ohms tests? Is it a blip?

 

[tomtoo]

Any idea what the 2 Ohms test parameters are that @amirm used for the various phase relationship 2 Ohms tests? Is it a blip?

Iam sry. Dont know.

 

[somebodyelse]

And if the nearest jack is a negative terminal, and the outside sleeve of the dc plug is also negative, then depending on the circuit it might be fine even if they do touch if they share a ground.

The amp is bridged so the 'negative' terminal is also driven. If you connect it to the sleeve of the DC plug the amp _should_ go into protection - see datasheet section 9.4.1.3

 

[Doodski]

The amp is bridged so the 'negative' terminal is also driven. If you connect it to the sleeve of the DC plug the amp _should_ go into protection - see datasheet section 9.4.1.3

I have had poor luck relying on protection circuitry with bridged amps.

 

[tomtoo]

I have had poor luck relying on protection circuitry with bridged amps.

Good point, but hey it's TI.

My TI30 still works.

 

[rvsixer]

Wow this little guy looks perfect for HT bypass duty, with the front panel RCA/XLR input selection. I am on the kickstarter list .

 

[Alex_Brouwer]

Just read this from the company in their message to me when the amp was sent:

"We'll provide a bundle including two V3 mono amps and a 48V/10A psu for no more than 260USD. That single 48V/10A psu can power the two sets of v3 mono simultaneously."

A pair of v3 mono and a topping d50 iii and I'd be good. Or should I go for a topping e70 will i notice a difference for the extra 250$ ‍

 

[Palladium]

Not trying to be inflammatory, genueinly interested... where are the differences or what needs to be improved? Is it across everything, Just more power?
Better power vs distortion or more stable reactive load?

I would very like prefer a stereo version, like many others.

 

[Bleib]

A pair of v3 mono and a topping d50 iii and I'd be good. Or should I go for a topping e70 will i notice a difference for the extra 250$ ‍

Unlikely. I expect d50 III to be very similar in performance.
Edit: I'm changing from e70 to D50 III, mostly for the remote but also curious about PEQ

 

[Alex_Brouwer]

Unlikely. I expect d50 III to be very similar in performance

That's what I'm guessing, I also don't have speaker worth thousands so good enough is good enough (a pair of tannoy 638. Currently powered by a ifi zen dac v2 and a dying old Yamaha receiver)

 

[ViperDom]

Wow this little guy looks perfect for HT bypass duty, with the front panel RCA/XLR input selection.

To clarify... Are you referring to the ability to have two diff input sources connected and be able to switch between them?
e.g. Have smart tv for HT plugged into rca, and computer for music plugged into xlr ?

Only downside i can think of is lack of ability to communally use a minidsp to control EQ & Subs.

 

[Billy Budapest]

Not trying to be inflammatory, genueinly interested... where are the differences or what needs to be improved? Is it across everything, Just more power?
Better power vs distortion or more stable reactive load?

Nothing needs to be improved, although as you stated the power vs distortion measurements could be better. Also, it looks like the rising frequency response issue in the upper treble has been fixed. But for the price, the performance is amazing.

 

[TonyJZX]

one might ask if any measurement improvements would be audible

and yeah i also feel like as the TPAs improve it kind of makes other more expensive competitors less and less attractive

 

[rvsixer]

To clarify... Are you referring to the ability to have two diff input sources connected and be able to switch between them?
e.g. Have smart tv for HT plugged into rca, and computer for music plugged into xlr ?

Only downside i can think of is lack of ability to communally use a minidsp to control EQ & Subs.

Yes indeed. Instead of the normally required trio of bypass switches (L/R/sub), two of the switches are eliminated using these amps (along with their RCA<->XLR adapter cables). Just use one bypass switch as normal for the miniDSP. I'm currently setting up 5.4.4 and 2.4 systems using shared speakers/amps myself.

 

[capslock]

Sorry if this has been asked before:

- The v3 mono is not on sale anywhere yet, is it?
- The v3 stereo is nowhere near as good (spec 88 dB SINAD). What are the differences? No PFFB for the stereo?

 

[staticV3]

The v3 mono is not on sale anywhere yet, is it?

Correct. Official launch will be on April 20th on Kickstarter.

The v3 stereo is nowhere near as good (spec 88 dB SINAD). What are the differences? No PFFB for the stereo?

The V3 Stereo does not have PFFB. There may be other differences as well.

 

[Overseas]

- The v3 stereo is nowhere near as good (spec 88 dB SINAD).

Well, if you use V3 Mono on RCA, the SINAD gap is not so big.

 

[capslock]

Well, if you use V3 Mono on RCA, the SINAD gap is not so big.

Interestingly, RCA has a higher noise floor but HD2 is a tad better and HD3 considerably. HD 4 and 5 no difference. I wonder if they do a symmetrical to single ended conversion on the input and screwed that up.