New APx555 Audio Analyser

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A few years ago I was offered a 2722 when the start up I had worked for finally went under for the second time..(I did not work for the final incarnation, but remained a close friend to one of the founders) I did not buy it in the interest of maintaining good marital relations, although it was quite a bargain at $12K.. I did enter the AP sweepstakes today, however I am not too worried about having to pay the considerable taxes as I think the odds of winning are pretty low.. LOL
 
With the 'bench mode' of the new analyzer AP claim to have kept the SYS2 style of use without the annoying bugs, at least that's what the rep said... that would really too good to be true. SYS2 hardware (incl. 2722) was a masterpiece but the quality of software hardly was any better than 'student level', if at all. It made many people swear and throw things... especially once you've seen how smooth eg the DScopeIII handles its user interface....
 
The datasheet and one of the videos show a FFT plot where apparently the signal has gone through the analog notch filter, yet the fundamental is still seen in original amplitude. That's an interesting feature (although probably in practice not that useful, actually)--I suspect they digitize the signal both before and after the notch filter, then somehow combine them again such that the information close to the fundamental is from before the notch, and everything else from after.

Is there any information available of the used ADC...

Likely the AD7760, or perhaps the ADS1675.

Samuel
 
I love this comment... :D

Hp

Although it is not fully clear to me what he's referring to. I'm aware of a few minor issues with the GUI, but the software basically is stable and does it's job. Don't recall having seen it crash in years of service.

Some users may have been overwhelmed by the complexity of the instrument, and the GUI doesn't do much if anything about hiding it. But once you get a grip on it, things are powerful and fast.

A first glance at the software for the APx555 suggests that they tried to hide the complexity, and make operation more foolproof. I hope that doesn't go at the cost of flexibility and power.

Samuel
 
The datasheet and one of the videos show a FFT plot where apparently the signal has gone through the analog notch filter, yet the fundamental is still seen in original amplitude. That's an interesting feature (although probably in practice not that useful, actually)--I suspect they digitize the signal both before and after the notch filter, then somehow combine them again such that the information close to the fundamental is from before the notch, and everything else from after.

The "Measuring ADCs and DACs with the APx555" app note shows the block diagram of the analyzer. Indeed they have two ADCs, and the one ahead of the analog notch filter is (in the digital domain) bandpass-filtered and added to the notch output. There's also a second digital notch filter for further fundamental suppression. Neat!

Samuel
 
Although it is not fully clear to me what he's referring to. I'm aware of a few minor issues with the GUI, but the software basically is stable and does it's job. Don't recall having seen it crash in years of service.
Well, yes, it doesn't crash. But it corrupts data all the time. Save more than 7 or 8 runs of an FFT-based measurement and reload it and add a new run, last trace is corrupt and no fix. Save any measurement with sampled data on a log X-axis (like THD vs Power) and reload it, display corrupt (linear X-axis), you can get the correct display back by clicking around a bit, but then you loose trace comments -- which means loosing overview. Delete a trace? Not possible without a special macro that takes hours for big FFT data (and completely impossible on older ApWin software). I mean how silly is that? How badly written must a code be that deleting an array of data is not possible?
These are NOT minor issues in my view, it really hurts workflow if you always have to take care about things like: will I be able to correctly reload the data later?
We basically came down to a only-one-measurement-per-file strategy, then load all the traces into a new setup for display when needed.

My colleage thinks absolutely the same, he's actually even more pissed off than I am. I have a coding background so I know and can understand that there always will be error and bugs but sure NOT on the most simple and obvious things, notably with a product of this reputation and lifetime. It really looks like they never did any serious testing at all, nor any thinking (why would a user ever want to delete a trace?)

In fact that's my thinking why AP actually ever got away with it, 'it's just audio and were #1 in the market, so what?'. In critical applications, like industrial control (where I initially come from), let alone medical and such, they'd be long out of business.
 
OK, is this notch at a fixed freq. (1 kHz) or allow they to track this notch over the full measurement bandwidth?

Of course this tracks the full generator range (as for the older analyzers).

Well, yes, it doesn't crash. But it corrupts data all the time. Save more than 7 or 8 runs of an FFT-based measurement and reload it and add a new run, last trace is corrupt and no fix. Save any measurement with sampled data on a log X-axis (like THD vs Power) and reload it, display corrupt (linear X-axis), you can get the correct display back by clicking around a bit, but then you loose trace comments -- which means loosing overview. Delete a trace? Not possible without a special macro that takes hours for big FFT data (and completely impossible on older ApWin software). I mean how silly is that? How badly written must a code be that deleting an array of data is not possible?
These are NOT minor issues in my view, it really hurts workflow if you always have to take care about things like: will I be able to correctly reload the data later?
We basically came down to a only-one-measurement-per-file strategy, then load all the traces into a new setup for display when needed.

Agree, the missing feature of easily deleting a trace is very cumbersome. I have not observed corrupted data.

Samuel
 
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I've done a test drive on an APx525 a week or so ago and the 'sequence' software is very good, but meant for production testing or something like that. You just set up a series of tests and then with one click it does everything and provides a (not so hot, to be honest) PDF report with all the findings.

Of course for development you'd want more direct control over the settings of all the generators and analyzers and that was the concept of the S2.

Now they appear to give you a choice which software approach you want to use depending on the job at hand and for me that's a great step forward in useablility.

BTW I did finally decide for the dScope III ...
Hope to get it next month.

Jan
 
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SYS2 hardware (incl. 2722) was a masterpiece but the quality of software hardly was any better than 'student level', if at all. It made many people swear and throw things...

So true. Never let an EE designer type do the software code. It surely wasnt an experienced professional software writer. Looks like something I would have come up with. With the bugs in the 2722 software, I thought it was just me and I must be stupid.... now I know it is still buggy. That saving multiple traces and storing/play back drove me nuts. I too just save one run at a time. If I paid full retail for it, I would have been quit disappointed. It seems capable of many tests to sota accuracy.... but scares me to try to use them. Too time consuming to get it right and know if it is right with bugs and all, I can never be sure. Takes too long to build up confidence in the test.... after you figure out how to do the test. Just isnt user friendly enough and I am not so geeky I want to plow thru it to make it work. I just hope the next test I learn to do -- multi-tones --- isnt as hard to do and has no bugs.


THx-RNMarsh
 
The APx500 v. 4.0 software is actually very sleek. I agree that the software for the SYS-2700 series leaves a lot to be desired, but AP really got after it with the APx500. At least from playing with the software in Demo mode, I get the feeling that AP really listened to the customer and designed the software to help the user.

I agree with the comments about the SYS-2700 software, though. The usability of the software definitely doesn't match the performance of the instrument.

~Tom
 
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