Audio Precision APx516B Review

[morillon]

While there is certainly value in being able to present data in the same format as AP software, I think REW provides a lot of the main functionality for free, with more flexible DUT audio I/O (no need for universal ASIO), and a simpler layout. Much more accessible for hobbyists.
I also don't remember exactly, but you might end up paying considerably more than $3300 for AP Flex once you add on some of the options you need. For example, Bench Mode (the "dashboard view" most often seen at the top of these reviews) is not included with the base package.

I also prefer the REW software layout for doing multiple comparative measurements; each sweep generates its own complete set of plots, and flipping between them is clear and simple. Also MUCH easier to import past measurements and overlay in REW, which in AP I think you have to do plot by plot; you can't just import a project file over top of an existing one.

The main advantage of the AP software is its automation capabilities, i.e. being able to set up a sequence of tests and have them run automatically. There is also a Python programming interface that enables scripting more complex types of measurements than the software itself allows, such as a 3D distortion over level/freq plot.

it was higher but multitones of pkanes can also carry out this kind of tests sequence...
Thread 'RME ADI-2/4 Pro SE - Auto-measured with Multitone' https://audiosciencereview.com/foru...-4-pro-se-auto-measured-with-multitone.43243/

 

[KSTR]

The main advantage of the AP software is its automation capabilities, i.e. being able to set up a sequence of tests and have them run automatically.

This, and the bullet-proof input front-end / auto-scaler. On the older systems (System Two Series) you have access to many options for the (auto-)scaler and also to the input gain of the notch filter, allowing different optimizations (for lowest noise or for lowest distortion).
The front-end has constant 100k input impedance vs. scaler settings and a 1-2-5-10 stepping of ranges. It is not lowest possible noise mainly because of the protection features.

So this is where you might have a slight advantage with something like the Cosmos ADC for some specific level ranges.

 

[KSTR]

Slight offtopic... The way the x555 measures in loopback, means it should be one of the best DACs in the market.
How well does it playing music? It must be the reference for all high SINAD DAC manufactures!
AP should start manufacturing DACs only...

Looks like this is the plot for the analog generator, not the DAC of the AP.

 

[Sal1950]

Just FYI Boss. You dropped this Review on Sunday afternoon. Clearly indicating that you still do not know the difference between a Work Week and a Weekend.

Adam, I think you're missing out on the whole point of being "retired".
We work when we want, don't if we're not in the mood.
The clock and calendar become irrelevant.
Your day will come. LOL

 

[amirm]

Slight offtopic... The way the x555 measures in loopback, means it should be one of the best DACs in the market.

As noted, that measurement is from the analog generator which only exists in APx555 series. Its DAC would rate around or below $100 to $200 DACs I measure.

Really, a lot of what AP does right is in analog domain.

 

[Sokel]

it was higher but multitones of pkanes can also carry out this kind of tests sequence...
Thread 'RME ADI-2/4 Pro SE - Auto-measured with Multitone' https://audiosciencereview.com/foru...-4-pro-se-auto-measured-with-multitone.43243/

Yep,I set it once and now just leave it measuring on it's own and have coffee
Multitone Analyzer is by far the most flexible,easy and (when someone takes some time to make a plan) just does it for you.

 

[restorer-john]

Topping DX5 + E1DA Cosmos ADC. THD = -128dB, THD+N = -118dB.

View attachment 350787

What about 4V in 4V out? gain panel is showing 11.91dB gain?

 

[jjaskuna]

The software is $3500 which is out of reach. If I really wanted to get into the business of testing DACS and Amps, I'd look for software (s) that did the same test as the AP Software. It may involve more than one piece of software, and it almost certainly would not output the same nice, lovely way the AP 500 software does, but there has to be other stuff (perhaps some of it even freeware) that would perform the same tests.

And if you wanted to use their software, it should prove compatible with any number of ASIO-enabled Audio interfaces: Api has even done much of the work for you in this regard as verified by their page regarding the software:

"Any ASIO-enabled audio interface should suffice with APx500 Flex. However, AP has thus far verified the compatibility of the audio interfaces listed below and configuration templates for these devices are included in APx500 software (v5.0.2 or later).

Guides for setting up Flex with one of these audio interfaces are also available (see Downloads tab). Each of these verified compatible interfaces offer quality analog I/O (<90 dB THD+N, 192 kHz SR) and stable drivers with consistent delay. Please contact the manufacturers, or their authorized resellers, for more information.

Danville Signal dspInstrument spDAQ, Echo AIO-A2, Echo AIO-SA, Lynx Aurora (n), Lynx E22, RME Fireface UC, RME Fireface 802"

Have you looked at subscription over full purchase? I used that with an RME interface( ADI Pro 2) for some time. And, my AP rep actually encouraged this approach before dropping all the money for an AP device. They even let me test the RME vs an AP interface at the same time, which allowed me to confirm the specs/sensitivity ratings I got from RME.

Note, the RME interface I used is not on their list of calibrated interfaces, but it is fairly straight forward to calibrate on your own. AP has a very strong technical note on the process.

 

[DamianW]

That is not what I was responding to.

Ok, QA403 is a very good value for money option.

As others have said Cosmos auto scaler allows for multiple other very cost effective options.

 

[amirm]

Ok, QA403 is a very good value for money option.

As others have said Cosmos auto scaler allows for multiple other very cost effective options.

So? Until I test them under identical conditions, that is immaterial to me.

 

[DualTriode]

A few months ago I went to a APx500 software training in the California South Bay.

The AP guys had both the APx555B and this APx516 on the table for demonstration. For testing speakers and headphones that 516 gets you up and going with enough precession for using microphones without the always on and always loud 555 fan.

The software is a huge expense plus the acoustic measurement software tools are more than a little bit more money.

Since AP has been under new ownership they seem to be more interested in marketing software than the hardware side of the market.

I did purchase a 5 year APX500 software subscription.

Let us see some FFT measurements scaled in Amplitude Spectral Density, dBV/Rt(Hz) where the noise floor is measured in real volt measurements not some dBrA compared to Volts output.

 

[CleanSound]

If there is a market for it, maybe the usual Chinese suspects will reverse engineer units like this and put out a few $250 comparable devices.

Such device exists already, Cosmos ADC. Ivan just need to make an unit that has the scaler, the APU and ADC and a DAC all in one with built in power supply.

 

[CleanSound]

The software is a huge expense plus the acoustic measurement software tools are more than a little bit more money.

I get it that it's a lot of labor for the software, but I find the value proposition very hard to justify. A small company like Topping, spends $35k on the AP, then what? $5k/yr on the software. $40k for first year of ownership, they have to sell what 90 units of the D90III to cover that cost?

Business is hard, and some of you who are on a race to the bottom of the barrel are complaining how SOTA DAC at $900 is too expensive?

We have to give these Topping and SMSL guys a lot of credit, true industry disruptors.

 

[Rja4000]

Noise however is high enough to sap fair bit of that performance bringing SINAD down to 106 dB. Here is my APx555 analyzer running the same test

Is there a way to combine the AP channels to get a lower noise ?

I do that with the RME : use an Y cable on the outputs to get one channel with lower noise and sum the 2 inputs in the device to get one channel input with lower noise.
That gives you up to 3dB lower noise.

Is that possible with the AP ?

 

[amirm]

Is there a way to combine the AP channels to get a lower noise ?

I do that with the RME : use an Y cable on the outputs to get one channel with lower noise and sum the 2 inputs in the device to get one channel input with lower noise.
That gives you up to 3dB lower noise.

Is that possible with the AP ?

I don't know. I should ask. Some drivers don't like to be combined that way.

 

[IVX]

Such device exists already, Cosmos ADC. Ivan just need to make an unit that has the scaler, the APU and ADC and a DAC all in one with built in power supply.

As I see, any AP reviews become advertising for my devices However, I see no reason to combine all devices together into a single case or add automation functions etc.

 

[amirm]

Oh wait, you were asking about the inputs? If so, there is no concern and I can test that.

 

[Rja4000]

Oh wait, you were asking about the inputs? If so, there is no concern and I can test that.

I was speaking of both inputs and outputs.
But only inputs are needed for DAC testing, of course .

By the way, the unit you have tested doesn't have the digital IO option, does it ?

 

[pma]

What about 4V in 4V out? gain panel is showing 11.91dB gain?

It is 4V in 4V out. I do not why gain panel says 11.91dB for the DAC. This new version of REW I have installed recently, I have to investigate it. Cosmos alone has about 4uV noise at 4.5V input, it is the limit for THD+N.

 

[restorer-john]

I do not why gain panel says 11.91dB for the DAC.

I figured it was referencing 3.94V as +11.91dB with respect to 0dBV/1 Volt. That's why I asked.