Simple output mutng signal

[StanleyB]

simple muting circuit

I have been trying to figure out a simple muting circuit that will either short or disconnect the output of a set of headphones from a headphone amplifier output. This circuit will be used to prevent that "pop" or high pitched sound when the amp is first powered up, or shuts down. Relay is an expensive option in this project. I tried muting transistors, but they seem to be affecting the sound quality somehow.

The amplifier is AC coupled to the headphone by the way.
Anyone got any suggestions on what else I could try?

 

[Ave_Rapina]

mutng

Hello

You cant use a normal transistor as switch becouse the output is alternated signal.

I recomend you an circuit that I use.

It as start delay and dc protection.




The layout




Regards

 

[IanP]

mu-tng

"Eliminating pop noise with external mute circuits"
http://www.wolfsonmicro.com/uploads/documents/en/WAN0151.pdf
To make this circuit working you will need to add a power-on-reset circuit ..
Here you will find an example of POR circuit based on 555 timer (you can set time to 0.5s, 1s or whatever you like) ..
http://www.kpsec.freeuk.com/555timer.htm

Regards,
IanP