PicoMite: can we explain/fix "ticking" when using PLAY SOUND


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mozzie
Regular Member

Joined: 15/06/2020
Location: Australia
Posts: 68
Posted: 11:56am 20 Mar 2023      

G'day Tom,
If the bypassing doesn't work can I suggest adding a 100n cap in between the output of the filter (junction of 2.2k resistors) and the volume control, and also re-configuring the volume control so that the wiper goes to the input of the PAM amplifier board.

The 100n capacitor will AC couple the amplifier and also limit the low frequency response to approx 160Hz, if you are using small speakers as mentioned this might stop the speakers / amp from clipping on a sudden signal change and attenuate the clicking sound.

The changes to the volume control will maintain a fairly constant input resistance otherwise the frequency response will change as the volume control changes, less resistance = higher cutoff frequency. Volume controls also don't like DC.

I am no EE etc, but many years of messing with audio gear