Q: TAS5717 HP EQ

Pls help for 2 questions about TAS5717 HP,

1. D/S shows HP function register is 0x05=13, it'll serious noise if I writing 1B (volume in headphone mode =0x08/0x09 (same as speaker channel volume)). Could you pls check it?

2. I can using 0x26(bq(0)) to change HP EQ and work good but cannot get correct response if using 0x27(bq(1)), 0x28(bq(2))... 

A: Re: TAS5717 HP EQ

Here's the summary:-

Issue 1.) High Noise reported on HP outputs, when register 0x05 is selected to set channel-volume registers to control HP-volume.

Debug Notes: As I mentioned in the earlier post, I found that toggling this bit also changes the PWM modulation mode from AD to Ternary. The data-sheet needs to be updated to remove this as an option (and only allow HP volume control)

Work-Around: As of now, the only option is to use HP-volume control register to update the HP volume.

 

Issue 2.) HP-EQ doesnt seem to be working (only 1st bi-quad works) all others have no effect.

Debug Notes: Register 0x50 bit '6' controls the HP-EQ enable/by-pass mode.

Resolution: Datasheet indicates this bit as reserved. This will be updated shortly. To Enable HP-EQ, please change Bit-6 status & also set bit '7' to by-pass speaker EQ mode.

 

Also, for issue-1, it might be worth trying the following experiment to see if any improvement can be made on the noise-issue. In HP mode, after toggling the bit status to channel-volume control (i.e. where the noise  issue is seen), please use register 0x20 to [00-89-77-72] to set device in BD mode.

 

Q: Re: TAS5717 HP EQ

Thanks for your great information.

I write 0x50 to 0F-70-80-40(Defult: 0F-70-80-10) and HP can using EQ.

But I found GUI has issues, I need to fill up EQ setting then write 0x50-it'll success.

If I write 0x50 first, last byte 40 will be chenged to default 10 when I fill up EQ then push "APPLY & DRAW" bottom-EQ cannot be load to HP.