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 39 (click to view)
DOUBLER
The Doubler replicates the input in another 2 voices and adds some detune, delay and feedback for the generated replicas. This creates rich chorus type effects as well as stereo enhancing and harmonic enriching effects. The Doubler is offered in Mono, Mono-to-Stereo and Stereo. It can go from very subtle to extreme effects. MIX: Range: 0 to 100; Default 50 This sets the balance between Wet and Dry. A 0 setting gives a 100% Dry signal 100 gives a 100% Wet signal. At 50, the Wet and Dry paths mixed are mixed evenly at -3dB. DETUNE: 0 to 25 Cents; Default: 8 This is the amount of detuned chorus effect, in cents, that the Doubler creates. DELAY: 12 to 100ms; Default: 11.3ms This is the length of the Delay effect added to the signal. FEEDBACK: 0 to 100; Default: 0 Feedback controls the amount of energy fed back from the voices� output back to its input. STEREO: 0 to100; Default: 50 At a setting of 100 the replicas are fully panned to left and right. At zero the replicas are panned exactly to center.
