Hello, i own the "supertooth Disco" portable speakers and lately am hearing a lot of nasty noise on the right channel, so after opening the speakers, i found a TPA3004d2, and started probing with my DS1054z oscilloscope; at first i didn' now how in the world i was going to see the waves because of how class d amplifiers work, but after AC coupling the inputs and enlarging the horizontal scale i found that there really is something up with the right channel:
Here is shown the left chanel in yellow and the right channel in blue, and as you can see there is major interference in the right(blue) channel.
After attempting to take a closer look at actual peak i zoomed in and got this:
So, as i am new to class d, my one and only guess is a bad filtering stage somewhere, maybe the LC filter at the output? or maybe a cap somewhere?
Opinions are appreciated
An externally hosted image should be here but it was not working when we last tested it.
Here is shown the left chanel in yellow and the right channel in blue, and as you can see there is major interference in the right(blue) channel.
After attempting to take a closer look at actual peak i zoomed in and got this:
An externally hosted image should be here but it was not working when we last tested it.
So, as i am new to class d, my one and only guess is a bad filtering stage somewhere, maybe the LC filter at the output? or maybe a cap somewhere?
Opinions are appreciated
So... I replaced the capacitors and the problem remains.. Hum, but also I got a better sound at what the noise sounds like, it sounds like the highs are there but the mids and low ends like bass distort, any ideas? And also what is the ideal way to measure the output of a class d on an oscilloscope?
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