TAS2557: electronic sound issue

Zoe Ko

Expert 3590 points

Part Number: TAS2557

Hi team,

When turn on the smart amp(Not enable EQ), the sound hear like electronic sound and it looks 2-4KHz not normal.

Enable EQ and adjust to reduce dB can inhibit electronic sound.

There are also with electronic sound when Smart amp flat protection use mid frequency.

1. Could you help provide evm calibration related material and teaching guide? And how to calibrate for this kind of the issue?

2. Manual calibration is with impedance parameter, is this cause to the issue?

3. Any other way can enter what kind of parameter?

Thank you!

10 months ago

Arthur Brown 10 months ago

TI__Mastermind 19105 points

Hi Zoe,

Is the output clipping? is the EQ reducing the volume such that the output is not clipping

Is this on the EVM or in the customers system? can you share more details about the system?

Regards,
Arthur

Zoe Ko 10 months ago in reply to Arthur Brown

TI__Expert 3590 points

Hi team,

Let me check it's their system or EVM and get back to you.

1. The microphone recorder test they saw 9~12dB plus at 2~4KHz and then quick down and go back.

2. 2~4KHz EQ reduce and still with the electronic sound. It's normal if not turn on smartamp so should not clipping issue.

3. The Fs is 123Hz for the speaker. Smart amp is set at 892. Is there any impedance parameter if no calibration?

4. combined_configuration_0_TuningMode_48KHz.cfg write with I2C as attached. 4544.combined_configuration_0_TuningMode_48KHz.cfg

Thank you!

Arthur Brown 10 months ago in reply to Zoe Ko

TI__Mastermind 19105 points

Hi Zoe,

Apologies for the delay due to the US holiday,

I will review this and give my feedback within 48 Hrs

Regards,
Arthur

ZongYuan Pan 10 months ago in reply to Arthur Brown

Prodigy 40 points

Hi I'm Mark . My account is broken and reply from my colleague's account.

Please info me (Mark.Wang@aver.com) when you have the feedback . Thanks.

Arthur Brown 10 months ago in reply to ZongYuan Pan

TI__Mastermind 19105 points

Hi Mark,

Sorry for the delay, I had overlooked this issue, I will check it and give you detailed feedback tomorrow

Regards,
Arthur

Arthur Brown 10 months ago in reply to Arthur Brown

TI__Mastermind 19105 points

Hi Mark,

I also found some unexpected distortion in the attached .cfg file, but when I configured the amplifier with PPC3 GUI it was all working as expected. What did you change in the PPC3 GUI?

Can you recreate the desired settings in PPC3 and create a new .cfg file. perhaps something unexpected happened which caused this distortion?

Zoe Ko said:
The Fs is 123Hz for the speaker. Smart amp is set at 892. Is there any impedance parameter if no calibration?

It is recommended to characterize the speaker and use the speaker model in PPC3. This will give the best performance from the speaker. you can characterize the speaker with the learning board 2 https://www.ti.com/tool/PP-SALB2-EVM.

Regards,
Arthur

Arthur Brown 10 months ago in reply to ZongYuan Pan

TI__Mastermind 19105 points

Hi Mark, Zoe,

Can you please provide the .PPC3 file that generated this .cfg file?

Regards,
Arthur

ZongYuan Pan 10 months ago in reply to Arthur Brown

Prodigy 40 points

smartamp.zip

Hi Brown ,

file as attached.

Arthur Brown 10 months ago in reply to ZongYuan Pan

TI__Mastermind 19105 points

Hi Mark,

I found that with this PPC3 file, when I configure the device using the PPC3 GUI I am not finding any distortion,

but I found that I was able to reproduce the distortion in the end system integration configuration when I select incorrect values for the Fs and the BCLK frequency.

I believe the issue here is that the PLL settings are being generated incorrectly because the fs and the BCLK frequency where not selected correctly.

for the EVM the correct values are fs=48kHz and BCLK=3.072 MHz.

if your end system is using 44.1kHz then you should select 2.822 MHz BCLK. (or whichever is matching your systems settings)

Regards,
Arthur

ZongYuan Pan 10 months ago in reply to Arthur Brown

Prodigy 40 points

Hi Brown,

I set source clock to MCLK 12.28M. it works.

I set 12M measured from i2s another record setting. My mistake.

Thanks for your help.

Arthur Brown 10 months ago in reply to ZongYuan Pan

TI__Mastermind 19105 points

glad i was able to help. I will close the thread.

Regards,
Arthur

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TAS2557: electronic sound issue