I’m going to detail how I built my first MIDI guitar and of what transformed from this. This project came about when I was asked to play second guitar with a friends band. It was immediately obvious that the lead guitarist was so strong that my rhythm efforts were barely noticed and what the band really needed was someone to fill in all the little bits that add to the overall flavor of the tunes they played. Sure some songs benefited from some back up guitar but almost every number they covered contained some signature keyboard part or percussion.
At first I built up a keyboard rig and would wear a guitar at the same time. Although this works and is quite common but when you add my duties of setting up the PA it becomes quite the task and the floor space that gets taken up is considerable. What to do?
My next idea was to ditch the keyboard rig and add a guitar to midi converter. This worked so well that I eventually set out to make a dedicated guitar and experimented with many different pieces of equipment. First was a Roland GK pickup on my Strat and a Roland GR-33 MIDI guitar converter. These worked fine but the GK had a number of faults one being that it picked up my unclean playing as extra notes which rang out all sorts of strange noises and the GR-33 although being rather large still required an additional synth to achieve all the sounds I needed. My rig was no smaller if I required an extra synth for all my sounds.
Thinking that I may just go to rack gear I picked up a AXON AX 100 MIDI guitar interface and a couple of 1U rack synths. Unfortunately I dealt with an unscrupulous ebay seller who had lied about the condition of the unit and shipped it to me with all the boards loose in the box. This was a lengthy setback as I slowly repaired the device and in the meantime continued on my quest to build the perfect MIDI guitar.
I had decided I was going to base my build on the Fender Thinline Telecaster and found a local luthier selling a beautiful body and another guy had a new Telecaster neck. Then I scoured ebay for the rest of the parts, I wanted to use as much of the Telecaster Deluxe model parts as possible including the recessed neck plate that I liked so much on my Strats. For the MIDI gear I had decided on the full kit from GraphTech, the kit is also sold in smaller packages and as parts so I found a number of sellers who had pieces and built up the full kit, this way takes longer but there are savings to be had.
Once there were enough parts to get to work I designed out my control layout and wiring diagram. This guitar was to have 6 tiny pickups that replaced the Telecaster saddles, the saddles had wires that were to be connected to the GraphTech boards and all that needed some special treatment to keep the stock appearance I was going for. First the guitar was built up to play so intonation could be done, this allowed the position of the saddles to be marked on the bridge. The guitar was then disassembled and tiny holes were drilled directly underneath each saddle hiding the wires.
Under the bridge slots were cut with a milling machine to allow the wires to travel unseen to the control cavity. A new cavity on the back of the guitar was then milled for the GraphTech boards and another cavity milled for a double battery holder to allow the guitar preamp to operate without need for the MIDI controller.
The preamp was for the GraphTech “Acoustiphonic” piezo saddle pickup, this gives a super clean guitar signal that is often used to simulate acoustic guitar sounds which I found quite pleasing but since acoustic guitars require a different type of sound reinforcement you need to work this out. In my case I used a small acoustic preamp and fed the signal into the mixer input on the GR-33 then out to the PA. Nice solution but now I found the need to either have a double switching solution to keep the acoustic/electric signals going to the right amps or run two cords to the guitar, one guitar cord for the acoustic and the 15 pin midi cable that also supports the guitar audio output.
Running two cords is a lot harder than you think, sure you can bind them together but there’s some psychological trait that when you stand and play a guitar you only turn one direction and you end up twisting your cable, one small guitar cable twists up quite easily and the ends are made to allow the cable to swivel without disconnection but two cables turn into a knot and the swivel does not work anymore when there’s two cables. It was a pain and I just went with longer cables that took more time to become a knot. I checked out wireless but that only eliminates one cable so I just forgot about it.
With the Axon working except for the backup battery circuit which would need some attention but right then I was stumped on. About this time I had the guitar finished and created these two test tracks, this one was done in one take with just me on guitar with a backing drum track making for simultaneous distorted guitar, acoustic guitar, organ and piano, the other is a country test with some fiddle.
Returning to the internet I found a forum where some users had actually repaired their AX100. I posted about my battery problems with a request for anyone who may have a schematic. Surprisingly the designer of the unit responded privately saying he would provide the information I needed provided I would respect his wishes and not repost it. He also added that I should sell that unit because he was just about to release the next generation and it was better at everything and better than anything else on the market.
Shortly after the Fishman Triple Play was released I sold off this guitar and two GR-33s and one Axon AX100 and bought myself this new wonder and a brand new Les Paul Jr. in TV yellow with the extra money. The Triple Play ended up going on a Strat but I might buy a second mounting kit for the Junior.
The new MIDI converter is completely wireless and tracks infinitely better than the GK and slightly better than the GraphTech Ghost. The Ghost does have a few advantages and I could see myself building another guitar, for instance GraphTech has a nylon string pickup, I’d like a nylon built like an electric. Also GraphTech has awesome tech support and every question I ever had while drawing those schematics you can see above was expertly and quickly answered.
Since the start of this project I’ve moved twice and converted my entire studio from racks of analog gear to working completely in computer so the new device fits better into my workflow. I don’t miss the Roland and Axon units or the built in sounds of the past units which were starting to sound dated.
If I ever wanted to add piezo it just means going to stereo cables and not dual cables because the Triple Play does not pass any analog signal. On the other hand I may not need to because of the increased sensitivity and faster tracking guitar patches on my synth provide very useful sounds. The other day I wanted to add an acoustic guitar part and started to plan out how I was going to run around and grab a guitar, mic, cables, preamp, etc. when it occurred to me to just select a patch on LogicProX. Not only did the patch work but I ended up changing my mind and using a nylon string patch which I felt worked better.