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TPA3125D2 Ticking

Other Parts Discussed in Thread: TPA3125D2, TLE2074

Hello! I have been testing out producing an amplifier using the TPA3125D2 speaker amplifier in BTL mode to double the power to a speaker. The design was based entirely on the schematic from the datasheet. The input and inverted input are provided via a TLE2074 opamp. The idea was to product a small but simple guitar amplifier. It is powered by a 15V 4A adapter salvaged from a laptop.

I built it once successfully then had issues with the guitar's preamp section and now when I try to power it up, I get a very rapid tick from the speaker instead. I have rebuilt it and am still getting the same ticks. Is there anything I can do to resolve this issue? What could be causing the ticking? I have provided the diagram of the prototype that I built on some veroboard. 

 

  • Hi, Jason,

    Sounds like a neat project!

    While it discusses a different device, I suspect you are suffering from the same issue as described in this post. I think if you study that post, it will help you resolve your issue.

    If not, let me know...

    -d2

  • Hi, Jason,

    I just ran across this post, and it might be helpful as well.

    -d2

  • Hi Don. Thanks for the quick reply. I have ordered a few new inductors to see if that's the problem. But I'm wondering if the output filter is really necessary. Since it's being used as a guitar amp and not really for hifi applications, I don't need a very wide frequency response. I'll try it out and see if it works but I'm wondering if there are any long term concerns to worry about if they were permanently left out.

  • So I've tried it without the filter and it works! I guess the problem was with my inductors. However, the output has a little crackling going which becomes more prominent when there's a quieter input signal and there's an audible high frequency whine. When the input signal is at a low level, there's some distortion in the output. When I turn up the input signal, the distortion goes away but I get a low frequency oscillation except when I play the guitar. Would the filter help with this?