Need Audio Grade Cap for Mute on LM3886 ???

[Droidiphile]

Hiya guys!

I see a lot of threads on using the mute function to suppress power on pops in the LM3886. But I cannot find any mention of whether or not the type of capacitor will affect the sound quality. Refer to Rm and Cm in the datasheet.

Should I use an audio grade cap, or is a cheap aluminum electrolytic acceptable in this case? My thinking is that if these components have an affect on gain, then it is possible they will affect sound quality.

Thanks for any help you can offer !

[thetube0a3]

I'm using standard aluminum electrolyics. I believe almost 1000uf at 25V. The cap has no effect on sound.

[tomchr]

Looking at the LM3886 equivalent schematic (see data sheet - or attached figure), the mute function is implemented with an analog MUX that switches the bias current between the main input pair and an input pair that has one input grounded (mute error amp). When the mute function is inactive, the mute circuitry receives no bias current, hence, will have no impact on sound quality.

There is, therefore, no reason to go with a boutique cap on the MUTE input. 100 uF ~ 1000 uF aluminum electrolytic will work just as well. Just make sure it can take the supply voltage.

~Tom