A little background and some notes
This build guide should enable you to build a RE-303, provided you have sourced all the parts in the current version of the BOM. For any updates to this guide please visit http://www.re-303.com
The build guide and BOM assume to build the RE-303 with an original NEC processor taken from an original TB-303. This would seem to make the most sense, since we need a known reference build and we are trying to replicate the TB-303.
This way if you have an aftermarket CPU such as the RE-303 CPU, RE-303 PX or a quicksilver CPU, you will be able to refer to the instructions with those devices and it will make sense in regards to the build document.
Some important things to note, there are no ic sockets in the BOM, so you may wish to order some in. Also do not fit a socket for the cpu if using a 3rd party cpu as vertical space is limited.
There are no pot brackets in the BOM, Adrian on the forums is currently working on making some, in the meantime you can use wire straps, this is explained later in the guide.
There currently exists no off the shelf solution for the switching sync socket, there are instructions in this guide on how to make one with a generic 5 pin din socket and a dpdt switch. These parts are not listed in the bom but should be obtainable easily.
The BA662 clone has place for an optional trimmer and resistor, we recommend fitting those parts. They are listed in the BOM but here are the needed mouser part numbers for clarity. R3 Trimmer, Top Adjust 3223J-1-503ECT-ND resistor R4 Chip Resistor (on back of PCB) 311-10MGRCT-ND
There has and always will be a lot of “voodoo” with the 303 circuits. Personally myself I build so called “dice roll” machines which basically have no preference to selecting parts (except for the right type) then doing one adjustment (if needed) to make them match my real TB’s. I’ve included more details on the “dice roll” at the very end of this guide, I would recommended it as it is very simple to do and you can forget the sockets and solder your transistors in (as they should be)
Ok let’s get started, before we start properly there’s a few things we should do to make life easier later on in the build.