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@QuantAsylum QuantAsylum released this May 22, 2019

1.74 (May 2019)

  • Changed behavior so that "press to cancel" is no longer shown once testing has completed. It is closed before user is asked to make graph selection
  • Changed behavior so that cancelled tests never plot partial data
  • Added File->Save bitmap to graph dlg
  • Added in black color to graph color options and trimmed color space overall
  • Fixed bug where first data point with PC Audio Mirror enabled sometimes wasn't getting captured.
Assets 3

@QuantAsylum QuantAsylum released this Jun 17, 2019

Release 1.75 (June 2019)

  • Changed PC Audio startup delay to be 2X user setting for PC Audio delay (previously it was fixed and couldn't be changed)
  • removed un-needed fields from speaker test plug-ins
  • Added ability to specify dBr units. This is useful when using measurement mic as input. This permits the ability to specify mic sensitivity and permits reading dBSPL directly on display
Assets 3

@QuantAsylum QuantAsylum released this Apr 22, 2019 · 1 commit to master since this release


  • Bumped audio pump thread priority and buffer size as with new Win1809 release it was showing skipping at 192Ksps. Not sure why this started happening.
  • Previously, when setting to default the codec was always reset, which required a DC settling. Now, the reset only occurs if the sample rate has changed. This change was for Tractor
  • Codec reset now only happens when actual sample rate change occurs. Previously it occurred when defaults were set. This was causing clicking on Tractor 0.91 release.
  • Removed ASIO hooks in QA401 interface. Use Asio401 instead.
  • If you are evaluating Tractor, you should be using Tractor release 0.91 or later with this QA401 build.
Assets 3

@QuantAsylum QuantAsylum released this Apr 4, 2019 · 1 commit to master since this release

After installing this version, please re-plug the QA401 to ensure the FPGA is updated!

This is a quick-fix to address the issue on some units with the attenuator cycling forever. The symptom is that you run the program, plug in the QA401, wait for it to configure, and then disable the attenuator. At that point, the attenuator will cycle on and off forever.

Originally we couldn't duplicate the issue here at all, but today we found a unit that exhibited the behavior. What is looks like is happening is the relay response times are a bit uneven. The attenuator consists of two relays, one for the right channel and one for the left channel. If the relays are perfectly matched, then they both click open and closed at the exact same time. If they are not, then one goes first, and a millisecond or two later, then next one clicks.

The detection logic assumed they both clicked at the same time, but thus there was a single overflow event from the ADC--this event is what drives the overflow detection logic.

But if the relays aren't perfectly matched, then you see the OVF go high while the first channel changes state, and then you see the OVF go high again a short time later.

What is interesting is that you can hear this--on some units, engaging the attenuator sounds like a single click. On a problem unit, you will hear a click-click, separated by a mS or two in time.

The problem may be exacerbated by low USB voltages. In other words, if you are using a USB cable with 26 or 28 AWG power conductors, the response time could worse as the voltage driving the relay is low.

In any case, there is no reason to install this version unless you are having trouble with the endless atten cycling.

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@QuantAsylum QuantAsylum released this Apr 2, 2019 · 1 commit to master since this release

This has more changes to the logic and timing for the overvoltage circuit. If you aren't having trouble with the attenuator on your QA401 being too sensitive,, then you should stick with your current version OR if you are looking for the latest software, then install 1.726.

If you are seeing an issue with the attenuator being too sensitive, the please contact support. We'd like to know about it.

Thanks, Matt

Assets 3

@QuantAsylum QuantAsylum released this Apr 1, 2019 · 1 commit to master since this release

This is a quick fix for some that have had trouble with the attenuator cycling. In release 1.72, the over voltage protection circuit was made more sensitive, but on some units it is too sensitive. This backs off on that by changing the OV minimum from 500 uS to 1 mS. In other words, if the ADC reports an overflow from 1mS or longer, then the attenuator will be forced on.

If you haven't experienced any trouble, there is no need to download this. Nothing else has changed.

Assets 3

@QuantAsylum QuantAsylum released this Mar 30, 2019

UPDATE1, Friday 29 Mar 2019 ~5PM PST: We've already received a report this didn't fix the exception when loading the plug-ins. If you are stuck at that issue, this build won't solve it. Hopefully this weekend

UPDATE2, Friday 29 Mar 2019 7:50 PM PST: This seems fixed now. The new release version is 1.726B. You should see that in the EXE download below.

There are a lot of changes to the graphing subsystem, even if though this indicates a very minor point release. There are also 3 new plug-ins. The plug-ins have been renamed and re-structured. See this post HERE to get an idea of what the names mean and what the graphs look like.

There are likely a lot of bugs still lurking in the plugins. Internally, all range checking and number validation has become driven by c# user attributes, which means lots of details can be 'decorated' onto a variable and then a validation engine will check it automatically. And given the scope of changes, there are bound to be some cut and paste errors. So, if you see something strange or unexpected with plug-in warnings or validation, please drop a note to 'support' and we'll check it quickly.

The last release had problems (that release has been pulled) with exceptions when some tried to access the new plug-ins. Most likely that was old plug-ins that didn't have the correct call sigs. The installer will not clean out all DLLs in the script directory before installing. So, if you have written your own DLL it will be deleted. We need a plan for handling user plug-ins that hasn't been worked out yet. But contact us and we'll figure something out.

There has been a change to the FPGA code. Now, the FPGA can detect if an overflow occurred during an acquisition and it sets a sticky bit to indicate such. This way, you can know after an acquisition if the hardware protection circuit interfered with your measurement. This was needed for the QA401H, and it will be exposed there in the next release.

If the attenuator state is changed via an API call, the API will pause for 500 mS IF a hardware change is needed. The relay is very fast (1-2 mS) but the longer wait is needed for DC settling.

The MIRROR checkbox in Settings now as a user-adjustable delay associated with it that will be applied if freq or amplitude is changed. This was needed for bluetooth speakers and the extra buffering done by those. If you are testing bluetooth speakers, let us know if you need help getting your setup tuned.


  • Fixed bug in parsing of plugin ranges introduced by 1.726 checkin of new parsing logic
  • Added gain offset to FR plugin
  • Chnages to output impedance plug-in so that it can cope with 4/8 ohms
  • Added range indication on the display. This will appear if the overflow bit from the ADC asserts at any poitn during the acquisition.
    this is a warning that what is seen should be treated with suspicion as the relay may have been in transition
  • The THD versus Power plugin will now optionally manage the attenuator
  • Changing attenuator state via API call will pause 500 mS if hardware must be changed
  • Added API call to indicate if overrange was experienced during acquisition
  • Added PWR IMD versus Power plugin
  • Added DAC THD versus Output Level plugin
  • Added AMP THD versus Output Level plugin
  • Removed ASIO driver
  • Install now cleans out scripts sub dir
  • Mirror now has delay associated with freq and amp changes
Assets 3
Mar 30, 2019



@QuantAsylum QuantAsylum released this Mar 21, 2019

Release 1.725 (March 2019)

  • First release of Wow and Flutter Visualizer (see Visualizer-> Wow and Flutter)
  • Added HTML help some of the more difficult to understand plug-ins and visualizers
  • Added the ability to abort a THD(N) versus Power measurement if the power AND THD exceed certain thresholds
  • Fixed errant bug on right channel phase display
  • Added range checking to more plug-ins. This is part of the architecture change in the 1.72.

[Update 29 Mar: EXE has been pulled due to exception issues with plug-ins. Please use 1.726]

Assets 2

@QuantAsylum QuantAsylum released this Mar 13, 2019

Release 1.72 (March 2019)
Release 1.72 replaces the existing graphing subsystem with something more generic and flexible. As it stands in this release, the functionality isn't all the way there yet, but it's already more flexible than that prior implementation. If you write software, the most appealing thing about the new plugin architecture is that no code is required for the UI. Now, the user settings are just decorated with properties which defines their behavior and the UI is auto-generated from the properties. There are some things not yet done, such as range checking across user settings, but those will come. If you have an idea for writing a plug-in, send mail to support at quantasylum and we'll get some sample source for you. But you can also decompile some of the plugins to see what is going on.

Also added in this release is a much faster over-range detect circuit. The previous implementation worked over a 20 mS averaging window, the new one works over a 1 mS window. If 500 uS out of 1 mS involve an overflow event, the attenuator will be engaged automatically. And then released 1 second later. For now, this is your hint to engage the attenuator, but an upcoming release will automatically do this if you configure it as such.

Finally, the ability to start and stop tone generation programmatically was added. To start the generator, use

QA401.GenerateToneStart(1000, -20); // Generate 1 KHz at -20 dBV

and to stop the generator call

Assets 3
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