Stonker said:
Yes, I saw that. You can buy templates and stuff.
Thinking out of the box, I wonder if you could build some kind of interface cable and mount the electronincs in an amp top box.
I've seen people fool around with that sort of thing, but it isn't a very good idea, unless you do it right. Those guitars rely on piezo elements in each bridge saddle, and each string has its own input. If you were to put the system in some housing external to the guitar, you would be faced with the problem of getting the six signals to that external housing. Why is it a problem?...
Firstly, you would need to deal with choosing a non-standard cable system. I would recommend using the ethercon connectors that those guitars use for the VDI interface. You could also choose a Roland GK interface cable/connector, if you want. (Just make sure you're happy with the reliability of the interface you choose. I am assuming that you want it to be gigworthy.)
Secondly, you would need to deal with the fact that the piezo elements have a very high output impedance. If you connect the piezos directly to the cable, the parasitic capacitance of the cable will create a filter that will cause you to lose a lot of low frequencies. If you are familiar with traditional piezo-based guitars, buffering is an absolute must for decent tone. The same physics apply here, even though you're driving a digital modelling system. If you want the guitar to sound good, you need to buffer each piezo element before its signal hits the instrument cable.
Thirdly, you would need a piezo buffer with individual outputs. Most commercially available buffers will take many piezo inputs and sum them to a single output, because most guitars have a single output. I am not sure if anyone makes a piezo buffer with independent outputs, so you may need to build one yourself.
Fourthly, (and this may or may not be a consideration to you), if you build your own buffer, you may need a fair bit of cavity space to house it on your guitar. If you do it on protoboard, the pcb will be a bit large. I would do three buffers on one pcb and three on a second pcb, and stack them up, to save space. Alternatively, if you really want to go all out with the project, design a pcb with software, and pack the components closely together. There are companies that will manufacture pcb boards from your design, if you send them the file. Expect to spend $50-$100 on the pcb board, if you do this.