QA402 Audio Analyzer [Retired]
The QA402 is an improved replacement for the QA401 Audio Analyzer. The QA402 initially began shipping in early May 2021.
Jan 2022: The QA402 has been replaced by the QA403.
Update 17-Aug-2021: The QA402 is on backorder. Given the scarce part availability, we don't yet know when it will be back in stock. As soon as we do, we'll start taking orders again.
Update 5-Aug-2021: We have caught up on all backorders. New orders generally ship in 24 hours.
Update 30-July-2021: We have started shipping backorders and expect to have all shipped by 5-August. After that date, we will resume normal shipping cadence (normally 24 hours).
Update 7-July-2021: We are accepting orders again. Orders placed today likely will not ship until late July or early August. We will not accept orders if we do not see a path to delivery. So, if you are able to order, it means we are confident we can deliver in the next 4-6 weeks. If you place an order, we can cancel at any time before the order ships if needed.
Affordable Audio Analysis
The QA402 is our 3rd generation of audio analyzer and can provide a wide range of audio measurements, making it a cost-effective addition to your bench. Unlike a sound card, the QA402 offers isolated and differential input and output, with input handling up to +32 dBV (40Vrms). The QA402 offers 8 input range, from 0 dBV up to 42 dBV full scale (note the max input, however, is +32 dBV). The output drive is also differential, with 8Vrms (+18 dBV) single-ended or 16Vrms (+24 dBV) balanced.
The QA402 is powered from a powered USB hub--most modern hubs can readily deliver the 900 mA the QA402 requires. But the small size and the fact that our different accessories (mic pre, programmable loads) are also USB powered, the upshot is that your backpack just got a lot lighter if you are debugging away from your bench.
The QA402 can operate standalone, or with an accessory such as the QA451 or QA471, further extending its utility. Automation via APIs is straightforward using the QA402 REST interface.
The product brief below has more information on product, including detailed specifications and loopback measurements.
Specs and performance on the QA402 here: QA402 Product Brief and Specs PDF
Wiki Getting Started
Wiki QA402 API
MORE READING: WHAT DO YOU WANT TO MEASURE?
Much of the content below was created with the QA401, but it's still relevant to the QA402.
Power Amps (5W to 1000W):
- Measuring Amplifier Noise with the QA401 and QA451
- The Basics: Power Amps
- Measuring a 300W Class D Amp
- Fast Tube Amp Characterization
- MERUS MA12070 Class D
- Evaluating Class D Amps with the QA401
- Swept Measurements
- Automated Amp Testing
- QA40x and IMD Measurements
- Rapid DAC Evaluation
- Measuring DAC performance using Notch Filters
- Measuring DAC performance using Notch Filters #2
LDO and Component Noise
Outboard Processing Gear
- Automating EQ TEsting using Masks
- Characterizing a Tone Knob using Expo Sweeps
- Quantifying Fuzz
- RIAA and User Weighting
- Automating EQ Tests
- QA401H, REST and Python
- Low-cost Test Setups
- QA401 Headless and Linux
- Tractor: First Look
- QA401H, Ubuntu and VirtualBox