A quick search and what I've mostly found are expensive commercial level converters.
There is another couple of approaches that can be tried, are less than optimal, make me cringe when I think about proper hi fidelity practices, but may be "good enough".
They're cheap, so no harm done in trying them.
The first... Buy a couple of these:
From here, or your local store...
http://www.radioshack.com/product.a...name=CTLG_011_002_016_000&product_id=273-1380
Connect the 8 ohm secondary to the audio inputs on your audio device and the primary to the audio inputs on the extra sat connector. You can go from the centre tap to one side, if the audio level is too high. You need one for each channel (2).
Downside of this? Frequency response may not be what you hope for, depending on how good or bad these are, and how picky you are.
Bad practice number two, but still works:
Create a voltage divider out of the input by driving the unbalanced audio into the balanced audio inputs.
Get a couple of 330 ohm resistors and put the audio ground on one side and the audio signal on the other. (In other words, instead of connecting them directly, connect them through two resistors on each channel.)
This works for all the wrong reasons. It's not the right way to make the conversion, but the voltage drop accross the input creates a difference in the signal levels, and fools the input into believing a differential signal exists. Unfortunately, it gets hit with a higher signal level than is necessary, to get the desired volume level.
Positive: Better frequency response.
Negative: Greater chance of distortion, not as good isolation as the transformer.
Of course the best way is a proper converter. I'm hoping to get the pac audio unit working with my Sat this weekend, and have it all selectable through the radio. My chances? 50/50...
I'll have to look up the pin numbers for you...