I (S-Tek, only one part of AG-KW) got a X0XBox (TB-303 Clone) Kit from xoxshop.de in Berlin last Friday (21th of June 2013), to make a little mid summer project. It comes with all parts you need to build the whole unit incl. another transistor to decide by yourself how the oscillator especially the Pulse Wave should sound. You can also decide how the frontpanel and the LED’s looks like. I decided to get a black one with red standard LED’s. I call it my little „DeathStar“ Now!

The following pictures show you how I build it from scratch.

There was some little parts missing in the Kit, but I hope the Xoxshop owner brings me the missing Knob for the Pattern Selection, 2 rare Tantal Capacitors and 4 bar spacers for the LED’s today. Only depends on his part suppliers. So I can finish it and make some ACIIIED!!! hopefully in the end of this week. =)

After the final soldering and checking all points in the making manual last wednesday, the Box was sound like big Shit. Damn!
I lost many hours and the half of my soul to find the error haha. On saturday Bruce came to me and we just found out that the 220K Resistors were wrong. They had only 200 Ohm.  Its hard to see that on the crappy colored resistor bodys. But no problem,  google helped like always. The X0XShop owner send me new Resistors and 3 new ICs for the Sequencer section. They where also broken after the 200Ohm Resistor madness. But now, all is fine.

Last step was to tune the OSC and Cutoff with the trimmer TM4 and TM5 and TM6 (for Cutoff). I did this with a freeware guitar tune software.
– at first, make sure the Tune Poti, TM4 and TM5 are centered
– open the Cutoff and put Env and Decay to 50 or 60%. Maybe also Accent
– pull down the Resonance to zero
– crank up the Volume
– go into Keyboard mode (or Midi Play mode for  using in a Sequencer with)
– play the lowest C note on your X0Xbox
– trim TM4 to note C (at 440Hz) now
– after that play the C note at the end of the X0XBox Keys and trim TM5 to Note C(one oktave higher)

At the End you only have to trim TM6 for the Cutoff Frequenz now. I did this with Accent, Decay, Env, Resonanz and Cutoff at zero position.

Final X0XBox