Fosi Audio ZA3 Amplifier Review

[SoySalsaPicante]

I have no experience with the WiiM Pro+.
But from what I've read, the output can be set to 2 V, 1 V, 800 mV, or 500 mV.
Personally, I'd keep it at 0.5 V, even lowering the WiiM's SINAD (well below the audible threshold), but ensuring it remains within ideal operating range with the ZA3.

[WiiM Pro Plus]
Line Out Revel
2 Vrms - SINAD 111.7
1 Vrms - SINAD 109.4
0.8 Vrms - SINAD 107.6
0.5 Vrms - SINAD 103.8

@Pep2020 Yes, I concur with this assessment by yallkok, although I would suggest maybe start with 1V. It didn't occur to me that you had adjustable output voltage at your source. This will allow you to raise your digital volume cap and make better use of your volume adjustment range.

 

[yallkok]

@Pep2020 Yes, I concur with this assessment by yallkok, although I would suggest maybe start with 1V. It didn't occur to me that you had adjustable output voltage at your source. This will allow you to raise your digital volume cap and make better use of your volume adjustment range.

1V is close to the clipping limit.
Why go so far out of spec?
They're usually very generous, too...

 

[Pep2020]

Set it at 800mV. Volume limit at 90%.

Sounds great. I think it allows me to use volume range better. Thank you both

 

[Witterings]

Anybody else running a pair as mono blocks and if so do you find there's quite a difference in output volume for each of them?

 

[kawal]

Got a ZA3 from Aliexpress and even with RCA it measures better than in the original review .
SNR 92.6dB and 0.0013% THD at 5W / 8 Ohm load

 

[kawal]

Multi tone is very clean as well - this is at 8 ohm at 5W.

 

[yallkok]

Got a ZA3 from Aliexpress and even with RCA it measures better than in the original review .
SNR 92.6dB and 0.0013% THD at 5W / 8 Ohm load

How many volts did your test source have at its output?

 

[kawal]

How many volts did your test source have at its output?

I do not recall the voltage - but the volume adjust was at max. Looking back at the screenshot actually shows that the voltage was 214mV RMS input to get the 5W output.

 

[yallkok]

I do not recall the voltage - but the volume adjust was at max. Looking back at the screenshot actually shows that the voltage was 214mV RMS input to get the 5W output.

You're right, I hadn't looked at the graph properly.
It's all clear.

 

[kawal]

You're right, I hadn't looked at the graph properly.
It's all clear.

I bought to amp to gift to my son but wanted to test it prior to gifting it. I was not sure if the Aliexpress one will be legit so I figured I would test it. The price on Aliexpress with coupons was way better than refurb from vendor directly.

BTW the QA403 is a pretty nice tool. Not without its own issues but pretty good overall. The automated tests are the best thing. Just setup and let it rip. For the higher output amps I do have to use external attenuators. But up to 200W the QA403 can measure without external attenuators.

 

[kawal]

Yallkok .

While I haven't tested 2V input I can confirm that 1V will achieve max power as the measured gain from RCA input is 29dB or 28.183X . I haven't measured gain from XLR at this time. Will this matter for music - probably not as music is not the same as test tones and music level vary even from album to album unless normalized. And who listens to the music turned all the way up? Either way if your DAC has no volume adjust you will have the ZA3 turned down a lot . If you do have Volume adjust on a DAC that will be turned down to normal levels so either way no problem. In case you need every dB of dynamic range you will not be using these toy amps.

Power at different input levels RCA

 

[kawal]

Gain measured from XLR inputs in my unit is 37dB . That is very high . Turning the volume knob from max to the 3 O'clock position reduced the gain to 27dB. Channel mismatch at this setting is good (0.2dB )

 

[peng]

I bought to amp to gift to my son but wanted to test it prior to gifting it. I was not sure if the Aliexpress one will be legit so I figured I would test it. The price on Aliexpress with coupons was way better than refurb from vendor directly.

BTW the QA403 is a pretty nice tool. Not without its own issues but pretty good overall. The automated tests are the best thing. Just setup and let it rip. For the higher output amps I do have to use external attenuators. But up to 200W the QA403 can measure without external attenuators.

Does the QA403 come with any measuring probes? I am interested in one for measuring preamp, dacs only, are the necessary probes of good quality available on Amazon? Thank you.

 

[kawal]

QA403 comes with no probes or cables included . It comes just with the unit and nothing else. The inputs and outputs are BNC so you can make your own cables or use 1x oscilloscope probes. You want a probe that can be switched to 1x do not use probes with 10x as it will change the response curve of the system. The cheap $10 probes work just fine as they are designed for above 1Mhz work. I purchased a few probes and a few RCA to BNC adapters. I made my own RCA to XLR cables.

 

[scruffy1]

so, amazon had a special on the fosi za3 for $199.99 delivered overnight (with 48v supply) - arrived thursday, in time for a good friday

i'd been reading a lot about it, and having become accustomed to the klipsch promedia 2.1thx in the study (with smsl dl100 and eq'd with peace) the wharfedales in the living room just didn't "sing" with the old nad d3020v1with quite the same authority

added a pair of tekera xlr cables in the order, and cleaned up the system (and the living room)

so currently - old school htpc in the antec nsk2480 case > topping e70 pushing matched 5v signal to the fosi, driving my pair of wharfedale 10.1 and the 10.gx active sub, and.... wow ! loving it ! the nad was a good thing in its day, but 30w mean vs 120+ is no contest, and the wharfedales at 6ohm with a sensitivity of 86db have suddenly taken a deep breath...

the e70 is at -3db, and with the za3 at 10 o'clock it is plenty loud in a 5x7m room - using the software as my remote volume, with flac at native 44100/16bit

there's a sneaky akliam dd2 bluetooth also, as the topping bt died and their repair options are non-existent; it can receive flac files from the nas using neutron on my re-purposed oneplus 5T on a dedicated 5g wifi channel at home > ldac , for "casual" convenience, but without actively listening it sounds pretty much as good

i'm rating it as good, but my experiences with amps is limited to the nad, and previously my luxman L2 that needed more work than i could do