Please help me build this

I am trying to get the relay trigger on my Sonic Frontiers to power up the switched outlets on my Monster 5100. Here is what SF emailed me, but I'm very uneducated about circuits and need further help. I was told I need a STEREO male-male mini plug cable, 12 V (DC) power supply and a relay. Thanks in advance:

For the trigger output, you would have to build a small circuit using an external 12V supply (even an AC adapter):

On the Line 1 connection, the tip and ring are connected - there is no connection on the sleeve, therefore the plug that's inserted must be stereo, not mono.

Since there's no voltage between them, it doesn't matter which way they're wired. When standby is pressed, the tip and ring are connected together, so its best use is in a logic circuit that is activated by a low input (i.e. when a 0 input is given to a gate, caused by shorting it through this connection, the output switches on a relay).

An alternative to a logic circuit would be using it as a simple power switch (i.e. route the 12V positive from a power supply to the tip, the ring in series, in a fashion that breaks the connection when off turning off the power, and closes the connection when on so the 12V makes the connection):

12V-------Line 1 tip Line 1 ring-------trigger input (tip)
ground----------------------------------------trigger input (sleeve)

The Line 1 tip and ring close to complete the 12V path to the trigger input.

A suitable power supply should have low internal impedance to prevent itself from being loaded down while powering the relay coil.

Similarly, the IR input has tip+ ring- connection on a stereo plug, and an external power supply is needed to power the IR receiver, which typically has 3 connections (+12V input, IR output, common ground). Depending on the model, you may be able to use the same 12V supply as the relay, but check the manufacturer's instructions. The IR input to the Line preamp should not exceed 12V.