Want to convert amplifier output to input level

[rkc7]

I want to get a little creative in my home audio system. I have a bunch of things I want to put into a 5.1 audio system (Klipsch 5.1 Promedias). The only thing is, they require analog signals. What I was considering was using a AV receiver to switch through all of my inputs, and so I can have multiple video inputs to my TV with only one input. Now, since my system has it's own amplifiers and crossovers I was just going to convert the amplifier output signals to input signals to my system. I have this little device I used to have in my car which could convert the amplified head outputs to line-level output, but it only accomodates 4 channels, so I need one more. It looks to be a small transformer in series with an adjustable pot (the resistors aren't for the inputs I was using). But, I have no idea what value or type the transformer is. Anyone have any idea on how to tell, or even how I can build another converter? By the way, it's a PAC OEM-1 module, I've included a pic. Inputs are on left, output on right.

[pinkmouse]

The transformers may just be for isolating the load, to prevent noise transmission.

It might be worth starting off with a simple experiment, and 5 preset pots, like the ones you have on that board, to attenuate the signal from the power amp.