Combine mono and stereo signals to stereo headphone

Hello everyone. As the title implies, I'm trying to to combine mono and stereo signals for a stereo headphone. I'm not by any means an electronics expert, so please have pity on me...

From what I understood in this thread ( I wired my gig according to the attached diagram, but I'm barely geting any audible signal.

Can someone please tell me what I did wrong here?

Thanks a lot in advanced!

Welcome to ETO

of course your thread could not be opened. You may open the thread and copy the link at the top of window and paste it here.

The link at the bottom of this page shows the thread. It uses resistors that REDUCE the signal levels and REDUCES the stereo separation.

In order to add together left and right stereo channels without signal reduction and mix in two mono signals then you need an active mixer circuit that probably uses an opamp.

Here is the very poor circuit from the other thread:

By using that link,thro firefox6.0.2, i get this message "Page not found" . that is waht made mde me seek for a workable link.
May be you are able to open. i had copied the content anfd it is here



I had changed the http to h**P for the legibility of the link's err. The closing parenthesis and the semi-colon, made it unworkable , perhaps.

The link shown at the bottom of this page is:
https://www.electro-tech-online.com...ereo-audio-signal-to-stereo-headphones.94550/