simple music on hold circuit

[Babybearjs]

I found this on the web. could this be multiplied 4X to work on a key telephone system?

[rdelius]

You can wire a transformer across the holding resister to inject music. Some line  cards have a jumper to eneble or delete MOH and you can cheat and inject it at the option jumpers..

[Babybearjs]

that's an Idea!

[dc4code]

Wow, thank you! I actually needed this right now! (Like exactly right now how did you read  my mind!!!)

[Babybearjs]

you are welcome Dylan! I found it online and have known about it for years! But, I don't do PC Boards, so it explains the circuit, but I can't build it..

[robert_m]

Is their a specific system you need this, many PBXs have a MOH or MOH Adapter (separate). but they basically do what that circut does. 

I personally use the ATT adapter and an external mp3 player with 20 MP3 songs in it that are royalty free and it just plays them in sequence.