Stereo to mono input

[giralfino]

Hi all,
I have the following problem.

I built a small radio based on a mono FM tuner and a single channel amplifier. The output goes to a single speaker. Now I would also add an input for a CD, but don't want to add another amplifier and speaker, so I was thinking of converting the CD stereo output into a mono signal that can feed the (mono) amplifier.

I found the schematic for this solution (see photo), but would like to know if it is good or there are other better solutions not too complicated. If it is the correct way, are 1/8W resistors OK?

Thanks,
Ralf

 

[bob91343]

That should work well. If you use 1/8 Watt resistors, you can have as much as 11 Volts or so across each one, which is probably more than your CD player can put out. So yes, that is okay.

 

[Frank Berry]

Depending on the output impedance of your CD player, you might want to increase the value of the resistors to something like 10K. The results will be the same but it may be an easier load impedance for the CD player.

 

[Speedskater]

The Rane paper on Wye-ing:

Why Not Wye?