Note, that to change the behavior of the sequencer, you are not going to be getting your soldering iron out, rather, you are going to be starting up your favorite text editor and brushing up on your C skills. See FirmWarePatches for sequencer behavior modifications.
You can use any 5mm LED in the x0xb0x. However, you may want to use different resistor values in series. Before you go ahead soldering in all 40 LEDs and resistors, test out one or two with different resistor values until you feel like they're the right brightness. (The LEDs are not necessary for the x0xb0x functionality so you can build it and then test LEDs). The original LEDs are superbright reds, if you want to go with blue, UV, purple, or white, you probably want around 1K resistors. YMMV.
|Schematic||Power Supply||Voltage Controlled Oscillator||Voltage Controlled Filter||Envelope Generator||Voltage Controlled Amplifier||Headphone And Mixer||Digital Sequencer||Midi, USB and Sync|
|Fabrication||Building the Ps||Building the Vco||Building the Vcf||Building the Envelope||Building the Vca||Building the Headphone And Mixer||Building the Sequencer||Building the Midi and Sync||Finishing It Off|
|Testing||Testing the Ps||Testing the Vco||Testing the Vcf||Testing the Envelope||Testing the Vca||Testing the Headphone And Mixer||Testing the Sequencer||Testing the Midi and Sync|
|Mods||Ps Mods||Vco Mods||Vcf Mods||Envelope Mods||Vca Mods||Headphone And Mixer Mods||Sequencer Mods||Midi And Sync Mods||Finishing Mods|