After reading you're initial question and the link you supplied, I take it that you have 2 receivers. The smaller one is a stereo receiver with A/B capabilities which I'll call receiver #2. What you want to do is have receiver #2 play the same signal (radio or CD or ipod or whatever) as receiver #1 is playing.

I've no experience at this, but perhaps if receiver #1 has pre-outs, for the L/R channels, that you could connect these pre-outs to receiver #2 as input from say, axillary.

https://docs.google.com/spreadsheet/ccc?...amp;usp=sharing