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TAS2557: TAS2557 + LEARNING BOARD + PPC3 volume can't not up

Part Number: TAS2557

We use  TAS2557 + LEARNING BOARD + PPC3,want to see realtime sep & stp. 
in PPC3 rule,we need go to the Turning and Audio Processing page at first.

but in this page,amplifier volume force to -10dB(if use 4Ohmn speaker ,output power=1W)

Even if we increase the input volume stream over than -10dB, the volume will remain at -10dB 

Down picture is behavior


In conclusion ,how can we up the volume to 0dB ?
  • Hi Simon,

    First let me clarify that Learning Board is only required during speaker characterization. Other than that you may use the EVM only for evaluation and tuning.

    Regarding the attenuation you see at the output, it may be because the speaker model is incorrect. Let me ask a few things:

    • Have you completed the speaker characterization?
    • (You may first reduce the input amplitude. Do this carefully as high output voltage may damage your speaker) Within PPC3, if you access "Test and Measurement" panel, then click on either ROM Mode 1 or 2. Do you have larger output?
    • (You may first reduce the input amplitude. Do this carefully as high output voltage may damage your speaker) Within PPC3, if you access "Tuning and Audio Processing" -> "Smart Amp", then click on the "flip" icon on the top corner of "Characterization Data", modify Xmax = 10 and Thermal Limit = 1000. Do you have larger output?

    Let me know if there are any questions.

    Best regards,
    -Ivan Salazar
    Applications Engineer

  • HI Ivan,

    Thanks for your help 

    We set Thermal Limit = 1000,speaker can output large volume now

    We want know why speaker temperature  doesn't close our limiter(we use thermal Limit = 80 before)
    but volume is limited

    Best regards,

  • Hi SImon,

    For the speaker protection (thermal and excursion) to work properly, the speaker model has to be correct, otherwise the algorithm may trigger the protection unnecessarily.
    As I mentioned before, have you run the speaker characterization process successfully? The characterization data should be close to your speaker data sheet parameters.

    Best regards,
    -Ivan Salazar
    Applications Engineer