Bob has posted a tutorial HERE on using the QA403 for making a host of amp measurements. The amp under consideration is outlined in Chapter 4 (2nd edition) of the Designing Audio Power Amplifier book, and depending on options can do about 150W into 8 ohms. Some more background on the design considerations and tradeoffs was presented at Burning Amp in 2019.
I have both books on my nearest shelf in my office. They are that good!
Bob Cordell is an authority on audio amplifier design. In my opinion, his book ‘Designing Audio Power Amplifiers’ should be in the library of anyone who wants to engage in audio amplifier design. This book, in my humble opinion, together with Doug Self’s texts, is an important mine of news and information. In this regard, I recommend reading Chapter 26 (but Chapter 27 is also very useful) ‘Distortion and its Measurement’ of ‘ Designing Audio Power Amplifiers’ (second edition) for a correct interpretation of the results that can be obtained from measurements made with the QA403. Of course all this is just my own thinking
Thank you for the recommendation, I ordered the book. I love good reference books that people put thought and love into. Books still work even when the internet does not
Hi. Here is the “PwrOutputimpedence Options” plugin with the “Plot Damping factor” box highlighted in QA40x version 1.207. Perhaps you are using an earlier version of QA40x.
Once again, one would think a tab would be available at FILE to upload the latest software version. No, you have to search for it and then unsure of what version is being installed.
If you go to QuantAsylum.com and click Support and then Download, and then click on your product, you’ll go straight to the Github page of all the latest releases and what has changed.
The installed version can be found under the logo in the main window of the QA40x (of course, the “Suppress Logo ‘ option should not be selected in ’Edit” “Setting”).
