I am guessing those are samples that held within the circuitry, no point it having a built in synth just to recreate the same noises on the pull of a trigger.

If your talking about building a synth to do this then its mainly down to the techniques used to create the sound. I lot of the sounds your talking about are done by doing certain tricks with modulation, chorus, etc. You could build a modular synth based on the common techniques that are using vintage synths in reactor.

I would recommend you get hold some soft synths that are based on vintage synths. Pro-52/53, or have a look at the new Korg plugins, the MS20 manual shows the schematics for it if. You can also buy sample cds containing these types of sounds generally labeled as sci-fi samples. You local library will have then hahaha!!!

Or you could just go and buy a ray gun and sample it :lol: