Adding a line out to Yamaha keyboard

[diydidi]

Hi
I have a client who wants me to add a line out to his P85 keyboard. Any ideas on how to accomplish this?
I have managed to track down a piece of the schematic related to the audio section.
Much appreciated.

[MarkusBass]

The simplest solution is to add two voltage followers build with 4580 on a small universal board and feed it with signal form the outputs of IC102 and IC103. On the output there is half of the power supply voltage so you will need additionally a capacitor and a resistor to the ground.

Mark

[Jazz P Bass]

Depending on where the operator puts the main volume control (setting it too high may be an issue at the sound board), you could get away with using one of the 'phone out' jacks.

[bsco]

Not sure if I am on the right track here but I'll try.....hopefully I don't make an idiot of myself........is it possible to take a feed from the top of the volume control and send it to another jack through a couple of coupling caps?? Or will this load down the circuitry....I am sure that if this won't work, somebody here will let me know.......nicely!!

[The Dude]

A bit more info would help. The keyboard is stereo and the question states "a line out". Is the objective here to sum the stereo output, ignore one of them, or do we want 2 line out jacks for stereo? There are plenty of ways to accomplish this, but we need to find out exactly what the end goal is. Another question: Do we want the volume control to have an effect on the line out, or do we want it to be constant regardless of what the keyboard player does with his volume control?

[doctor]

The simplest way is to use the PHONE 2 output jack.

1. In order to match output voltage to the line out level,
few resistors of the PHONE 2 channel need to be changed,
namely new values should be:
R505 = R506 = 2.2K
R507 = R508 = 1K.

2. It is necessary to provide for measures in order to speakers
will not disconnected when plug is inserted to the PHONE 2 jack.
May be the pin #4 of the JK502 (PHONE 2 jack) should be shorted
to the pin #5.

[diydidi]

Thanx for the help guys. Will report back.