Fosi Audio V3 Amplifier Review

[Colonel7]

They were absolutely horrible to listen to. Instant tear your head off brightness.


No, you're just not understanding the problem. CERTAIN loads cause the issue, not all loads. Your xover likely simply doesn't cause the amp to misbehave. I have other speakers with much flatter loads that don't exhibit the problem.

Like I said this really needs to be tested in depth by someone like Amir or preferably Erin.

Like I said, we’ll have to agree to disagree. I’ve followed your thread on PETT and your conversation with PMA in his thread and I’ll call it interesting and not something I’ve experienced.

 

[Billy Budapest]

Great performance for the price.

 

[Thermionics]

I ordered one from Amazon today (thanks for the discount code). One question I have for Fosi Audio: is it possible to buy the orange knob, or was that only available for those that invested in the Kickstarter campaign (which I found about woefully too late)?

Thank you.

 

[Talisman]

I ordered one from Amazon today (thanks for the discount code). One question I have for Fosi Audio: is it possible to buy the orange knob, or was that only available for those that invested in the Kickstarter campaign (which I found about woefully too late)?

Thank you.

You can find it for sale separately on AliExpress for around 9 euros. You can also find the 48v power supply if you are interested

 

[natna]

Oops. I had tested it but forgot to post. It is now in the review:

Thanx so much! At least it's no a bad performance for the cost, I'd say...

 

[renaudrenaud]

I bought the 20a few weeks ago... I guess I have to go for this one also, they are so inexpensive. Fosi, please, wait few months for the next one.

 

[badspeakerdesigner]

Like I said, we’ll have to agree to disagree. I’ve followed your thread on PETT and your conversation with PMA in his thread and I’ll call it interesting and not something I’ve experienced.

I genuinely don't really understand your comments here. What are you disagreeing with? You haven't provided any real argument aside from "my setup doesn't have this problem" as if it's evidence for anything. I'm at ASR right?

 

[audiotron]

Just ordered one. Thanks for the review.

 

[Doodski]

Still odd though. The 48 V PSU has 1.5 times higher voltage so that means 2.25 times higher power. 89/34 is about 2.62 so at least one value is off.

The power measured is in RMS. The RMS power formula is.
Watts RMS = (Vpeak * 0.707) ^2 / R load

 

[MacClintock]

Amazing, quite powerful little amp, low noise and distortion, even looking good. If I would need anything like this, I would buy it easily. Great product.

 

[Thermionics]

You can find it for sale separately on AliExpress for around 9 euros. You can also find the 48v power supply if you are interested

Thank you! Ordered!

 

[ClassicGuy]

I wish the US Amazon listing has the 48v power supply. @Fosi Audio will Amazon have the 48v option?

 

[375HP2482]

Exactly and I know I can't really hear beyond 15khz anyway so for me (and a good few people here) the difference in the effective audible range will be tiny.

And yes I think these are a good match for cheaper speakers (maybe up to $500), if your speakers are beyond that price range, they probably deserve a more expensive amp.

If your more expensive speakers are below 92 dB sensitivity, I don't think they need anything better than this.

On the "load dependency" side, it would be interesting to test/measure the output of these TPA 3255 amplifiers when the full-output load is removed (no load). Though the Fosi spec sheet says "2-8 ohms," the Texas Instruments spec sheet lists no maximum load impedance.

 

[Timstunes]

tested:

This amp + su-1 can offer a great budget system ($200)

Add some JBL A130s ($199).

 

[Fosi Audio]

I wish the US Amazon listing has the 48v power supply. @Fosi Audio will Amazon have the 48v option?

Yes, we also provide the 48V/5A power supply here https://bit.ly/azus48v5a

 

[milosz]

In the review, Amirm says "State of the art DACs run on highly performant silicone"

Is this some new technology that is based on caulk?

 

[Fosi Audio]

I wanted to use this promotional code when buying an amplifier on AliExpress, but, unfortunately, it does not work.

Sorry for any inconvenience caused. We have sorted it out. The code is valid on Aliexpress now.

 

[digicidal]

In the review, Amirm says "State of the art DACs run on highly performant silicone"

Is this some new technology that is based on caulk?

I've heard that while those DACs are quite firm and natural, they are a bit less safe than the ones that run on saline.

 

[ROOSKIE]

That's not what happens with real speakers. This is what happens with real speakers, it will vary with load but this is what I got from an aiyima a07. I tested three a07's and got different rising responses towards the top end with each one but similar behavior of things starting to rise around 5khz (just the tweeter here and it's passive network, c note speaker).

While I'm not a big fan of the youtuber Andrew Robinson, he put out a video documenting the same problem, but he wasn't sure what the cause was, just that he was getting totally different HF responses with different amplifiers.

View attachment 293761

Same tweeter with amp that doesn't have load dependency (had woofer connected for this one, can ignore below 2k,). This seems like a good opportunity to market "non-load dependant" amplifiers from the budget amp makers. I've had people tell me it's just these speakers that an outlier, nope found plenty of commercial offerings with very similar impedence charts, like kef q150. Most people are pairing these speakers with cheap amps, I wonder how many complaints about brightness are because of this issue. I will continue to rate any amplifier with this issue as poor as I don't consider it acceptable and it is a design flaw in my eyes.

View attachment 293762

Hi, to show the load dependency you can not have 1 graph of the tweeter only and one with tweeter and woofer.

The woofer doesn't just suddenly take over at 2khrz and the tweeter stops.
Not even close, not even remotely close.
This comparison should be totally ignored. There may be load dependency but a complete re-do is required here.
Once you do that then re-post.

The c-note uses about a 3k+ crossover frequency and will be down 6-12db @2500-3k when just looking at the tweeter.

*you also need to make sure your mic is in exactly the exact same spot for compro above 10khrz

I anticipate much less variation in a proper compro than what you are trying to demonstrate here.

 

[amirm]

In the review, Amirm says "State of the art DACs run on highly performant silicone"

Is this some new technology that is based on caulk?

I always chuckle when I see this mistake and here I am making the same. Corrected.