Archive of the former Yahoo!Groups mailing list: Discussion about the Korg PolySix synthesizer

... and it may be a good idea to buy the LEDs and throw them on a breadboard first. This way you can experiment and find the right resistor value. Their brightness relative to the originals will vary for sure so once you know the voltage that Andy is talking about, base it on that and find the resistance that suits your taste. On paper it may be one value but it may prove too dull or bright so it's best to see the min action before committing.