Fosi Audio ZA3 Amplifier Review

[Pep2020]

My Wiim Pro Plus with ZA3 trigger worked first time. Mono 3.5mm to 3.5mm lead, with mono 2.5mm to 3.5mm adapter.

 

[Witterings]

My ZA3 arrived today. It seems to work really well, though I'm having the trigger issue that some people have reported. After some experimentation and thinking, I'm wondering if it's manufacturing variation in how the trigger is wired up in the ZA3?

If you think about it, the trigger signal should always be sent on the T of TS/TRS - that means that it will work with either TS or TRS lead. My WiiM Pro Plus appears to send the trigger signal on T as expected. The Fosi only triggers when the plug is partially out of the socket - aligning the plug's T with the socket's R. I've tried this with TS and TRS plugs and it's the same. I'm not sure why Fosi would have used a TRS socket for the trigger to begin with (more readily available, maybe?). Being triggered on R seems like it must be a mistake.

Looking at the back of the trigger socket, I can see how it'd be an easy mistake to make:

View attachment 416916

(photo is from https://forums.stevehoffman.tv/threads/fosi-audio-za3-class-d-amplifier.1191955/page-2)

Tomorrow I'll wire up a TS to TRS lead, connecting the T of the TS to the R of the TRS. I'm pretty confident it'll work, but it'll be interesting to see for sure.

I don't know what a TS or TRS lead actually means but I just ordered a 2.5mm to 3.5mm mono lead and it works perfectly.

 

[obsessive9119]

TS is mono (Tip/Sleeve); TRS is stereo (Tip/Ring/Sleeve). It seems like mono cables work out of the box for a lot of people, but unfortunately not for everyone, which is why I think there might be some variation on how @Fosi Audio are wiring up the trigger socket.

The custom cable seems to have done the trick for me. I ended up using 2.5mm TRS to 3.5mm TRS because that's what I had lying round, and wired it so both tip and sleeve on the 3.5mm (Fosi) end were connected to to the tip of the 2.5mm (WiiM) end.

 

[andrelambert_]

For the same price, which one of the two do you think it's a better deal? Aiyima A07 Max with 48V PSU vs Fosi Audio ZA3 with 32V PSU. Speakers I will be driving are a pair of JBL Studio 580 Towers. My current amp is the original A07 with 32V PSU and I don't miss any more power as it's already plenty so I'm leaning into the ZA3.

 

[Bene]

I bought the Za3 because it's bigger and cooler and if you care...

 

[EddNog]

ZA3, due to the volume attenuator that cannot be bypassed, converts all signals into single-ended and then back to balanced before sending them through the chip. V3 Monos only convert single-ended signals to balanced before sending into the chip, and balanced input signals do not go through that type of unnecessary conversion, so if you’re planning to use XLR/balanced, might recommend V3 Monos instead. There is also the auto-on/off on the V3 Monos versus 12V trigger on ZA3 (I personally prefer 12V trigger).

-Ed

 

[obsessive9119]

I went with the ZA3 because I wanted the 48v PSU, and here that’s the configuration that’s available on Amazon (aiyima and V3 stereo both come with 32v). The 12v trigger and the looked sealed it for me.

so if you’re planning to use XLR/balanced, might recommend V3 Monos instead.

Does that matter in this scenario? Here balanced is about reducing noise between components, isn’t it? If this conversion caused any issues, it’d be reflected in the data, wouldn’t it?

 

[EddNog]

I went with the ZA3 because I wanted the 48v PSU, and here that’s the configuration that’s available on Amazon (aiyima and V3 stereo both come with 32v). The 12v trigger and the looked sealed it for me.

Does that matter in this scenario? Here balanced is about reducing noise between components, isn’t it?

This is ASR. Most people will say the difference is academic because both amps are transparent enough already that you can’t consistently pick one from the other in a blind A/B test once level matched.

-Ed

 

[T&T]

For the same price, which one of the two do you think it's a better deal? Aiyima A07 Max with 48V PSU vs Fosi Audio ZA3 with 32V PSU. Speakers I will be driving are a pair of JBL Studio 580 Towers. My current amp is the original A07 with 32V PSU and I don't miss any more power as it's already plenty so I'm leaning into the ZA3.

2 amplifier ZA3's in mono with 48v. using XLR, upgrading only 2 opamp Right channel and XLR and pulling out 2 opamps form the sub and the opamp on the left channel is way way better than V3 monos with upgrade opamps

 

[EddNog]

2 amplifier ZA3's in mono with 48v. using XLR, upgrading only 2 opamp Right channel and XLR and pulling out 2 opamps form the sub and the opamp on the left channel is way way better than V3 monos with upgrade opamps

This post won’t go well here at ASR.

-Ed

 

[T&T]

This post won’t go well here at ASR.

-Ed

Ohhh ...I see it...thanks Ed

 

[EddNog]

Ohhh ...I see it...thanks Ed

Yeah this won’t go well here either.

These people pretty much don’t believe one bit in subjective results, so if there’s no way to measure the difference between op-amps and/or consistently blind A/B them, ASR refutes the results.

-Ed

* the ASR method does not fully represent my own ways

 

[T&T]

Yeah this won’t go well here either.

These people pretty much don’t believe one bit in subjective results, so if there’s no way to measure the difference between op-amps and/or consistently blind A/B them, ASR refutes the results.

-Ed

* the ASR method does not fully represent my own ways

Is easy to A/B on mono you change the opamps in 1 mono and leave the other with stocks, them you will see if different voltage and gain in opamps sound different or not

 

[somebodyelse]

These people pretty much don’t believe one bit in subjective results, so if there’s no way to measure the difference between op-amps and/or consistently blind A/B them, ASR refutes the results.

People here believe subjective tests, but only when they're properly controlled to account for known causes of error. Blind testing is one part of that, but not the only thing to be careful of. For more details see:
https://www.audiosciencereview.com/...d-testing-you-are-doing-it-wrong-video.26809/

 

[kswenson]

I'm extremely happy with my ZA3. I will say that I'm TERRIFIED of that switch getting toggled to mono by an unsuspecting member of my family. Fortunately, the "stereo" position is downward, making it more difficult to accidentally destroy my right speaker.

 

[Alarchist]

I'm trying to figure out if I should go for the ZA3 or V3, I like the idea of balanced XLR's but I'm not sure it's really implemented in a a beneficial way on the ZA3 vs V3?

Quite a few of the tests on the unbalanced stereo V3 are better than the balanced XLR ZA3, so what's the benefit of using the balanced XLR's if the V3's unbalanced RCA's have:

Marginally better SINAD, nearly 3dB better SNR @ full power, 5-10dB better crosstalk.

I have a mix of PA and home gear, with high power class AB amps, Behringer DCX2496 DSP, Formula Sound Mixer etc, all sort of connected up with the hifi stuff including some old Linn Helix speakers currently powered by some older TDA2050's, but I want to have a play with some new amps testing across that and my PA monitors, which have high efficiency (110dB+) OS waveguide tops - Where amplifier hiss has always been a problem. So as low noise floor for them as possible would be good. I'd also maybe use the Fosi to play with building some portable battery DC system too.

Generally balanced inputs are good, and I'm thinking to get a Minidsp flex with balanced outs, but for a very affordable fun project test amp, the V3 looks better in some regards.

As a side note for affordable fun projects I also like the look of the Wondom BRU5, but I don't think that will be as quiet. I may just have to buy a couple of different amps and see what works.

TLDR: Has anyone spent time with both Fosi amps in different setups and noticed a benefit from the XLR ZA3?

 

[styr0]

Hi all, new member here who has lurked for quite a while. Just an FYI here. I just purchased my 2nd Fosi ZA3 amp from Amazon for $150.00 w/ the 48V 5A power supply, Model: JYH23Z-4800500-BF. Or so I thought.
For $150 I received the ZA3 amp & the 48V 5A GaN Model: FJ-GN224048005000 power supply.
I thought they sent me the 32 volt power supply instead b/c it was so much smaller than the other one. Checked here and sure enough I got the GaN PS.
In Red is the PS I just received & in Green is the supply I received in the summer. Currently this power supply is selling for $71.00 on Amazon and it's much smaller than the regular 5 amp 48 volt PS. It'd be a good time to buy if this is the Power Supply they're pairing with the amp.

 

[activio]

Guys, will za3 sound worse than v3?

 

[EddNog]

Guys, will za3 sound worse than v3?

Depending on your high frequency hearing and your speakers, they may or may not sound different to you, because ZA3 and V3 do not have PFFB, but V3 Monos do, so V3 Monos have a potentially more neutral sound in the high frequency range compared to V3 or ZA3. ZA3 and V3 Mono both have low enough distortion/high enough SINAD that they should otherwise be transparent in direct comparison.

-Ed

 

[T&T]

Guys, will za3 sound worse than v3?

I used to own 2 V3 monos but I prefer the ZA3 in mono in you are going to use XLR connection, I can not said for rca connection, In my case ZA3 sound much better with opams opa2604 than V7 vivid go figure out