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QA401 Audio Analyzer
QA450 Programmable 8/4 Ohm Load
QA150 High Side Current Sense Amp
QA460 Transducer Driver
QA470 Low Noise Mic Pre-amp
QA351 uV DC Voltmeter
QA350 Microvolt DC Volt Meter [RETIRED]
QA101B Mixed Signal Oscilloscope [RETIRED]
Recent Blog Posts
Automated Testing of In-Ear Monitors
May 28, 2020
The next few months will reveal another round of accessory products for the QA401. Next up is a tester for In Ear Monitors (IEMs) called the QA490....
Measuring Input Impedance
April 02, 2020
For some circuits, it's easy to determine the input impedance. For example, take a look at the simplified input stage of the QA460 Transducer drive...
Mic Testing with the QA401
March 01, 2020
Last week a post on the forum showed how to make an automated test for microphones that runs in Tractor. Recall Tractor is the standalone program t...
February 17, 2020
We previously looked at the phenomenon of speaker compression, which occurs when increases in gain in the the speaker output fail to track the incr...
February 06, 2020
Notch filters have always played an important role in measurements. In fact, before higher performance ADC and DACs were available, distortion meas...
NAMM 2020 and Speaker Compression
January 28, 2020
[Post by Matt] NAMM 2020 has come and gone, and as usual the event was informative and educational. I had an interesting discussion with a person w...
Automating Pedal Measurements with Tractor
January 15, 2020
We have a new forum located here. It's based on Discourse, which is a bit different form most forum software. Discourse is optimized for short, qui...
December 04, 2019
Let's say the first 50 units of your new widget prototype have come off the line. You're excited because this is the first time you've built more t...
Speaker Impedance Measurements
October 18, 2019
In late 2018 a plug-in was added for making speaker impedance measurements. This post takes a look at additional hardware requirements to be aware ...
Rub and Buzz
October 15, 2019
QA401 release version 1.81 (located HERE) adds speaker Rub and Buzz testing in the form of a plug-in. Rub and Buzz refers to a speaker test that ca...
First Look: Infineon MERUS MA12070
September 28, 2019
The growing portable speaker segment is resulting in some solid Class D innovation from silicon vendors. A new part from Infineon is especially int...
Release 1.791 and Portable Speakers
August 17, 2019
Release 1.791 (located here) has some tools for testing portable speakers & speakers in general. The portable battery-powered speaker segment i...