Yeah, I have one installed and will be at the meet on Saturday. It is the Sony XA-39MK2.

Bingo. Thanks for that information.

Here's the entry at Crutchfield, it sells for fifty bucks US.

They say: "The Sony XA-39II switching relay allows you to run two separate four-channel sources (an in-dash cassette and in-dash CD player, for instance) into your amplifier system. The unit features front and rear inputs for two separate head units (or any source with up to four RCA outputs), and front and rear outputs which can be connected to a 4-channel amplifier (or two 2-channel amps)."

Considering all that it does (properly handles four independent signals and amp remote turn-ons from two separate units), it seems like a bargain for fify bucks.

Dominic also describes a similar DIY device in this post and includes a schematic.

Any questions?

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Tony Fabris