Hello rompelstilchen,
Check the schematic below:
Guitar Jammer
The above is a Guitar Jammer designed by Silicon Chip magazine here in Australia.
I've made some modifications, but essentially its Silicon Chip's idea.
The project was designed to connect your guitar with your CD player or any other
low signal audio source (eg. PC Sound Card etc.), so you can jam with any of your
preferred music.
Each has its own separate volume control so you can get the equalisation between
the two inputs the way you like it.
Its good for 8 to 32 ohm headphones.
It has the option of using a 9 volt battery or a 9 volt plugpak. Its also reverse polarity
protected.
I hope the above might suit your needs.
Regards,
Relayer
All rights to Silicon Chip Magazine.
Taken from their October 2000 issue...