Yes, should work. I assume your BM3500 is 1 way. I connected a BL Video MKII to BS9000 via Masterlink and the audio aux link socket to the aux socket of my BM4500 (old 1 way). BS9000 is located in the mainroom, BM4500 in a linkroom. BM3500 set to A.OPT 2. Pressing CD, RADIO....activates the audio sources of BM4500, pressing TV, DVD,DTV....activates BM4500 in A.AUX mode and starts up the video source in the mainroom. Pressing LINK - CD (..RADIO, N....MUSIC....) activates BM4500 in A.AUX mode and starts up BS9000...But iy both systems are located in the same room, BS9000 should be set to A.OPT 0.....Hope this helps.
Stefan