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vs1011e volume change popıng

Posted: Thu 2019-12-19 22:14
by lobra07
ı have a costum board wıth vs1011e .. when playing mp3 file i try to change volume but every time i change the volume i get the pop sound at output
but when there is no mp3 file playing no poping happen
could any one help me with this problem

Re: vs1011e volume change popıng

Posted: Fri 2019-12-20 13:51
by pasi
How much are you changing the volume at once? Do the issues only come up when the change is crossing 6dB or 12dB boundaries?

"Pop" is a natural effect when the amplitude of the signal is changed by a large amount. When you change volume, there is discontinuity in the signal at the gain change point, and the larger the gain change and the larger the signal, the larger effect.

In vs1053/vs1063 the volume control tries to minimize the effect by delaying gain change to the next zero cross of the signal. The change can still be heard, because the human hearing is sensitive to the gain change itself, but the behavior in the frequency domain is cleaner.

A workaround is to change volume in smaller increments.

Also, in vs1011 going over the -6dB and -12dB points will cause extra complication because the calculation range is changed. (You could work around this by adjusting the software volume variables directly.)

Re: vs1011e volume change popıng

Posted: Fri 2019-12-20 15:20
by lobra07
i change the vulume step by step and is incrementing slowly .. and the poping appear in low ranges too .. i mean it happens in all ranges

questions 1. dose the poping happen if i send tow volume commands very fast without waiting for the secound to finish excute in vs1001e ?
questions 2 .. should i send the sci_vol command while sending data or should i wait to the data_req_pin go low to do that ?

Re: vs1011e volume change popıng

Posted: Fri 2019-12-20 23:32
by lobra07
there is something i forget to mention that im using the device in SM_DIFF mode

Re: vs1011e volume change popıng

Posted: Wed 2020-01-08 14:46
by pasi
1. Pop happens if gain is changed when the signal is non-zero. The amount depends on the signal level and amount of gain change. This is universal.

vs1011e has "analog" and digital volume control parts, so when you cross -6dB and -12dB, there may be a larger pop.

2. Keep sending data to SDI, or you risk another pop when the decoder runs out of data to decode.

For some applications we have used a slow fade-in / fade-out to gradually change the gain, but vs1011e doesn't have that kind of function.