For some reason I am having to introduce a delay (sleep(40 msec)) in my code just after I unmute (active SHDN Vcc goes to 0) an amplifier otherwise I get audio clipping. It seems odd to me. The amplfier's SHDN line is just tied to ground through a .1uF capacitor. Any ideas, am I not reaching true ground fast enough?

ex the following code allows audio with no clipping:

LibPlatform::Sound::amplifierOn();
threadfunc::sleep(40); // Sleep for 40 msec. Gives amplifier 'SHDN' time to reach true ground??

however, with this delay I am getting clipping:

LibPlatform::Sound::amplifierOn();
threadfunc::sleep(30);

The amp is a MAX98307

 

The amplifier plays when SHDN is at the supply voltage and it is muted when SHDN is 0V.

The datasheet shows the SHDN going high very quickly then the audio output beginning after a 45ms delay with no distortion.
The SHDN pin must be either 0V or the supply voltage, not floating.
Why do you have a capacitor to ground on the SHDN pin?

 

The datasheet shows the SHDN going high very quickly then the audio output beginning after a 45ms delay with no distortion.
Why do you have a capacitor to ground on the SHDN pin?

Sorry I was confused, there is a .1uF cap running from SHDN to Vcc I was looking at the datasheet incorrectly. Where on the datasheet does it show the audio output beginning after a 45ms delay?

EDIT: Oh I see now, I wonder if I can reduce this time?

 

The datasheet graph shows a delay of 45ms but the written spec says 40ms to 80ms.
To reduce the delay (and maybe cause a POP) you need external muting.