Electronics > Projects, Designs, and Technical Stuff
Analog Disovery as Audio Analyzer
(1/32) > >>
jaxbird:
First off, I know a lot of people on this board got some some misconception that audio is not engineering and everything sounds the same due to many of Dave's comments on the subject. If you feel this way, feel free to skip this thread.

Anyway, there is a lot of interesting engineering associated with audio. Personally I wanted to do some measurements on a couple of amplifiers using the software supplied with my Digilent Analog Discovery unit, but I really find it somewhat limited for this purpose, sure it will do most measurements, but it's very time consuming and the supplied software is a little buggy, not always showing the truth.

I am aware using a PC soundcard is an option (even up to 24 bits/low bandwidth) but I find the sound card option being somewhat limited as you don't know what level you are testing at and often very fiddly to configure.

The Analog Discovery is "only" 14 bits, so limited on the dynamic range, but on the positive side it's got up to ~10MHz+ bandwidth. Anyway, as I got some experience with the API from other projects, I have decided to write some dedicated software for this purpose.

Primary purpose is amplifier measurements.
jaxbird:
Here the screen to measure THD+N vs frequency at a specific power/output level:



Note, minimum THD+N is about 0.01% due to limitations in the Discovery unit. But unlikely anyone can identify distortion that low anyway, especially considering even the best speakers distort 0.1% +++ in an anechoic chamber without any reverberations. Living room conditions is unlikely to every be below 1% distortion even a low levels.

More important is the ability to analyze the harmonics causing the distortion, generally even harmonics are considered much more pleasant than odd harmonics.
Lightages:
Who said that audio electronics is not an engineering topic? It is very much so! I think you are mistaking the disdain here for woo woo claims in the audiphool realm as a disdain for all subjects about audio. Not so.

Looks like you have a winner there with that set up. The Analog Discovery is a great bit of kit and it is very capable of doing many things for a cheap price. I could only dream of having those capabilities when I was younger.

What amplifier are you measuring in that image?
jaxbird:

--- Quote from: Lightages on December 10, 2015, 05:38:08 pm ---Who said that audio electronics is not an engineering topic? It is very much so! I think you are mistaking the disdain here for woo woo claims in the audiphool realm as a disdain for all subjects about audio. Not so.

Looks like you have a winner there with that set up. The Analog Discovery is a great bit of kit and it is very capable of doing many things for a cheap price. I could only dream of having those capabilities when I was younger.

What amplifier are you measuring in that image?

--- End quote ---

Thanks, I agree, unfortunately some seem to lack the insight to discern the difference e.g. I've seen using a film capacitor instead of a ceramic as coupling being called audiophoolery, instead of common sense.

Anyway, thanks for the positive comment, much appreciated.

This is a measurement of a tiny little class D amplifier based on a Tripath chip, I will post more details.



jaxbird:
Here measuring the output level vs % THD+N, useful to know how many watts you can expect from an amplifier with a specific load:



Navigation
Message Index
Next page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod