How to derive a line level output from a speaker.

2022 02 23

 

This circuit uses a voltage divider to derive a line level output from a speaker inside low voltage low wattage devices like 5 volt powered electronic toys and 5 volt powered electronic musical instruments.
With a line level output the device can be connected to an audio amplifier or a mixer.
If into circuit bending, adding a line level output to the device first is always a good move.
This circuit uses three-legged switch S1 to direct the +output of the system/device to either the speaker or the line level output.
The parallel 22 ohm and 10 ohm resistors make one 8 ohm resistor to simulate the load of the speaker to the system when the speaker is switched off. These are an option and not a need. If the speaker is large and the wattage of the device is over 2 watt, add these.
The 10K and 1K resistors that make the voltage divider should be 0.25 watt metal film type resistors for best results and audiophile autism.

line output from speaker circuit