I am trying to couple a signal from a microcontroller to the output of an audio source, mp3 player, stereo, computer that will create audible sound at an earphone speaker. I am simply putting a 5volt square wave 1-10khz pulse onto the audio lines of the speaker.
It works fine when directly driving the speaker from the microcontroller, but when i connect the audio lines the pulsed uC signal is severly attenutated at the speaker. I believe that this is because of the extremely low output impedence of the audio amplifier driving the audio line??? It would seem that i need to buffer the audio line with something of a higher impedence?? It appears that i will have the same problem running the signal through an opamp configuration( follower) becuase of its low output impedence??
What would you recommend doing with minimal extra components being required??
Thank for the help
It works fine when directly driving the speaker from the microcontroller, but when i connect the audio lines the pulsed uC signal is severly attenutated at the speaker. I believe that this is because of the extremely low output impedence of the audio amplifier driving the audio line??? It would seem that i need to buffer the audio line with something of a higher impedence?? It appears that i will have the same problem running the signal through an opamp configuration( follower) becuase of its low output impedence??
What would you recommend doing with minimal extra components being required??
Thank for the help