Add Line Out to Old Keyboard

BeniRose

BeniRose

New member
I have an old Casio keyboard that doesn't have a line out on it, it only plays through the speakers. I figured I can take it apart and add a line out jack, but I'm not sure what it needs. Can I just get a 1/4 jack and put it in the same path as the speaker? Do I need to add any resistors? Any help would be appreciated, even if it's just a website tutorial on this kind of thing (I couldn't find anything).
 
BeniRose said:
I have an old Casio keyboard that doesn't have a line out on it, it only plays through the speakers. I figured I can take it apart and add a line out jack, but I'm not sure what it needs. Can I just get a 1/4 jack and put it in the same path as the speaker? Do I need to add any resistors? Any help would be appreciated, even if it's just a website tutorial on this kind of thing (I couldn't find anything).
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Yeah, just tap the speaker. 150 ohm series resistor downstream of the speaker and a 33uF/63V series cap should protect against just about anything--63V not really required, that's just what I keep a big bag of around . . .

I did that on my old TV which lacked a line out, works great into an amp for external speakers :)

if you want to get slick, use a normalling jack that passes signal to the speaker when no plug is connected and interrupts when a plug is connected. You have to be a bit more clever there since you don't want to defeat the series resistor nor put it in the speaker's path, generally there it's better to find the input to the power amp and tap that rather than the output.
 
Aw man, I'm so close to knowing what that means, but I'm just not confident in my knowledge of electronics. Would you mind drawing me up a diagram or something? I can't really read schematics either, so it'd have to be well labeled. Thanks so much.
 
Tapping off the speaker is not going to give you a real line out. As stated above you need to find the input to the power amp section and route that to your jack. Do you have a schematic? What is the model number of the keyboard?
 
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