Audio Precision APx516B Review

[amirm]

could you test dscope m1 by any chance?

I used the original dscope years ago. It too has excellent software but performance was not in the same league as AP.

 

[Eldus]

Nice review.... but I can't even figure out my RTA or the software on my mini dsp or is it my REW or my Audyessy xt . Dam this Dyslexia...
WHERE IS MY SELF DRIVING STEREO!!!

Dirac Live?

 

[Rja4000]

I really really hope we can persuade @JohnPM to add an API to REW so it can be scripted for automated test procedure execution though, that would really push AP

Which is the very reason I'm using Virtins Multi Instrument instead. At least, it was the original reason.
Now MI is way more powerful than REW.
(REW is perfect for what it's name stands: Room EQ)
But it's not free.

 

[morillon]

Which is the very reason I'm using Virtins Multi Instrument instead. At least, it was the original reason.
Now MI is way more powerful than REW.
But it's not free.

if they support your hardware...
between multitones, rew and virtins pro... we don't lack much...and at low cost... ;-)

 

[Rja4000]

The software is $3500 which is out of reach.

Depending on the options you want, it way be up to $8000...

But it exists as a yearly subscription, with all options included.

As an amateur reviewer, with little time available outside of holidays, I'd love AP to make a monthly subscription for non-pro use
I could then pay for one month during my holidays and perform 3-4 measurements...

Dreams are for free ;-)

 

[morillon]

The current model QA403 is quite amazing. (4V in 4V out)

View attachment 350662

You can hit -120dB (0.0001%) THD as is, loopback using its own DAC and ADC and get better again if you wanted to feed it with an even better gen.

it is an observation sweep sinad vs frequency and not only at 1khz which would be interesting
;-)
( you can use multitones with qa403?)

 

[Rja4000]

Would be interesting to see how this APX 516b compares regarding features and specs against the E1DA Cosmos ADC which is $179 on Ali Express.

You can't really compare.

First, the AP is meant for productivity and reproducibility.
In short: professional use.

With adequate manual setup, you may get similar or even better results measuring a DAC from E1DA ADC + APU + Scaler + some USB filter + a proper software... for one static measurement.
So, say, for 4V SINAD, it will work.
Buy you won't be able to perform adequately on a wider voltage range, nor with automation.

If you want to measure an analog device with it, you'd need to add a DAC and a proper level attenuation chain. That is even harder to automate.

The RME ADI-2 Pro or (better) ADI-2/4 Pro SE are more flexible on that level, and give similar top performance to the E1DA, but on a wider voltage range.

The pure (mono) loopback will fall a bit short of the APx555B in full auto (say we'd get 116dB where the APx555B would read 120dB) but will still be significantly better than the APx516B.

And you can still use the same tricks to get the final word on 4V SINAD: E1DA APU + Scaler, external attenuator... if you run that manually.
(Best I could measure was above 126dB SINAD for the Topping D90LE at 5.2V)

 

[morillon]

(the cleanest dacs tested here on asr are formidable audio generators at low cost...)

 

[Rja4000]

(the cleanest dacs tested here on asr are formidable audio generators at low cost...)

Their limitation (compared to an AP analyser) is when you lower the output level.

An analog attenuator is (much) more performant than just lowering the DAC output level.
That's where the APx555 will leave a standard DAC in the dust.
Of course, you may build your own attenuator.
but then it's all manual again.

The RME, with their automatic ranges, are doing better than a typical DAC on that point.
But they are an exception.

 

[VintageFlanker]

You can't really compare.

First, the AP is meant for productivity and reproducibility.
In short: professional use.

With adequate manual setup, you may get similar or even better results measuring a DAC from E1DA ADC + APU + Scaler + some USB filter + a proper software... for one static measurement.
So, say, for 4V SINAD, it will work.
Buy you won't be able to perform adequately on a wider voltage range, nor with automation.

If you want to measure an analog device with it, you'd need to add a DAC and a proper level attenuation chain. That is even harder to automate.

The RME ADI-2 Pro or (better) ADI-2/4 Pro SE are more flexible on that level, and give similar top performance to the E1DA, but on a wider voltage range.

The pure (mono) loopback will fall a bit short of the APx555B in full auto (say we'd get 116dB where the APx555B would read 120dB) but will still be significantly better than the APx516B.

And you can still use the same tricks to get the final word on 4V SINAD: E1DA APU + Scaler, external attenuator... if you run that manually.
(Best I could measure was above 126dB SINAD for the Topping D90LE at 5.2V)

Exactly what I was going to say. The Cosmos lineup + tone generator ("SOTA" DAC and REW) will give you some higher performance to get a single plot (also quite a bit better than the QA posted above)... But you sure will work a hell faster with an AP and its integrated DMM/Scaler and standardised test tones and software.

 

[mcdn]

Exactly what I was going to say. The Cosmos lineup + tone generator ("SOTA" DAC and REW) will give you some higher performance to get a single plot (also quite a bit better than the QA posted above)... But you sure will work a hell faster with an AP and its integrated DMM/Scaler and standardised test tones and software.

That though is a software problem. Shame REW isn’t open source or we could close the gap very quickly. Not all the way to the APx555 with its analog scaling, but very close given the high quality of modern DACs

 

[VintageFlanker]

That though is a software problem.

Nope. Cosmos works with both fixed input gain and high input impedance. The Scaler fix a bit of that, but it will never be as precise as an AP as it is. Not to mention, the limitation at 43Vrms to measure amplifiers (and most importantly, the gap between 10Vrms and 43Vrms, so you're working less precisely in this wide gap).

Shame REW isn’t open source or we could close the gap very quickly.

REW is indeed a SOTA software, even more considering it's free.

 

[welwynnick]

Interesting test. Anyone know how AP analysers compare with generic, lindustry standard, low frequency network analysers?

 

[amirm]

Does the analyzer have the voltage switch of 120/240 V ?

It automatically supports different input voltages.

 

[lewdish]

Oh it has the HDMI module, can it test for flaws in HDMI cables since the market is flooded w/ so many fake and non-compliant HDMI 2.1/2.1a/2.1b cables?

 

[amirm]

Interesting test. Anyone know how AP analysers compare with generic, lindustry standard, low frequency network analysers?

What network analyzer?

 

[amirm]

Oh it has the HDMI module, can it test for flaws in HDMI cables since the market is flooded w/ so many fake and non-compliant HDMI 2.1/2.1a/2.1b cables?

It can't analyze signal quality over HDMI. What jitter it can analyze may be a function of its own receiver than what is upstream.

On that topic though, ability to plug in different I/O such as HDMI is a differentiator compared to any ADC.

 

[restorer-john]

If you are using unbal (SE) "+" inputs, does the unit automatically short/relay the "-" input on the XLR and 4mm or do you check a box on the AP software?

 

[jjaskuna]

Awesome review. I'm eager to see BT updates for the DUO for 5.0. Maybe that's next in the AP pipeline.

 

[IAtaman]

View attachment 350633
We see that the gap is small during start of the sweep but once we get to around 0.22 volt, the APx516 auto-scales the input signal to better match its ADC dynamic range. This is much earlier than APx555 which runs "native" until 2 volts. Still, at lower measurement voltages, the gap is not that large.

Thanks for the review Amir. Definitely a lot more interesting to me than seeing yet another SMSL/Topping DAC with 120dB+ SINAD/

Are High Performance Generator & Analyzer separate modules added to the basic configuration? Do you recall what they cost? Without them, at least on the SINAD performance, the difference is a lot smaller between 516 and 555 it seems.

There seems to be tiny triangles starting at around 0.3V in the non HP version of the 555 as well - are those also auto scaling "artefacts"? When you say native up to 2V, it that for the HP version?

Now people are talking about it, I'd love to see QA403 measurements as well. It costs $600 - might as well get the QA403 instead of yet another DAC or an amp I don't need.