Turns out this was not the manual i was looking for. The concertmate 670 keyboard i have is a "Realistic" model made for Radio Shack and none of the diagrams on the owners manual i received matches up. HOWEVER, I must say the service Owners Manual provides was fast and efficient by being available online. The manual was in good readable condition and easily downloaded.
Thank´s for your help, I already recived these manual from you
Text excerpt from page 19 (click to view)
Simultaneous Speaker-Level and Line-Level Inputs
In some systems it may be desirable to use both the speaker-level inputs and line-level inputs simultaneously. For instance, if you have a stock head unit in your car, you may connect the speaker-level inputs of the head unit to the GTS100x. You may simultaneously connect a CD player equipped with preamp volume control to the preamp-level inputs of the GTS100x. The Universal Interface circuitry of the GTS100x will isolate the inputs from each other while mixing both signals. Therefore, switching from one source to the other is as simple as turning the unused source off and turning the desired source on. No other switches or relay boxes are needed.
When using this setup it is also possible, using the wiring setup shown at right, to allow either of the two sources to remotely turn on the ampli�er. This is not necessary if the factory radio is of the high-power BTL type and is connected to the speaker-level inputs. The Common Sense turnon circuit will activate the GTS100x when a powered source is used, and the conventional remote connection of the preamplevel source will activate the amp when it is used.
Dual Source Remote Wiring Diagram From Head Unit #1 Remote or Antenna Output
1N4001 Diode
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To GTS100x Remote From Head Unit #2 Remote or Antenna Output
1N4001 Diode
