ST Warlock - The Beginning (1)

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Today I'd like to talk about a very special project, the guitar I've been dreaming about building since before I actually started playing guitar, a decade ago. It's something rather complex, experimental and every detail is challenging.

This guitar have its own OS written for extensive MIDI control, a hacked guitar pickup with another handwound sustainer bobbin, custom designed preamp system and even its hard case is getting custom built for something really awesome I'll tell you about on another article.

Everything here is hi-tech and experimental. I invite you to join me on a tour.

I'm lucky and I know it:

I had the luck to meet amazing people, capable of doing amazing stuff and kind to listen to my ideas and consider it possible to achive instead of laughing at it. People that got excited to join me creating this project that got a lot bigger than my idea, bigger than myself.
I really need to thank Erik Zatti, the luthier that took care of setting and modding my 6 guitars and is building the seventh one, this one.
This dood is used to pass by my home to take some guitar of mine and get another one back to me like, 2 or 3 times a week! Simply because I'm kinda addicted to do lots of stuff to my guitars and I keep the research up with 2 or 3 while I need the other ones working 100% to gig and record, and he always manage to do everything I ask perfectly and just in time. This dood is like a guardian angel of the guitar players of my town.
He can listen to my ideas for long minutes, things I just brainstorm and things I've done lots of research, then break it down in a lot of complex details. When he takes a guitar to his place, he comes back with everything I've asked perfectly done. This guy is amazing. Seriously.

Hardware:

Breaking the project down a little bit, starting by the "more common features" we got lock tuners for stability, stainless steel jumbo frets for durability and confort and a Tune-O-Matic bridge with piezo saddles for acoustic sound wired to a channel of the custom preamp I've designed and built, ending on a "blend" knob for adding to the electric pickups sound.

Here's a demo of one of these bridges recorded in line for a raw sound listening.

Bridge Pickup:

My pickup of choice here is the Entwistle HDN, a british company that I found out by accident and got interested in their neodymium magnet pickups.
Here's some theory: Overwound pickups produce more output but sound more muddy and less focused, that's a classic "hi-gain pup paradigm" and happens because of the winding capacitance increasing, making the treble roll-of earlier. Overwound singlecoils sound fuller and less bell-like but humbuckers that already are bassier can get a real lack of definition here.
Pickups get a similar effect as some years later the magnet naturally weakens its magnetic field, some single-coils are even slightly less charged on the factory and delivered this way to the customers for this effect.
Guess what happens if you have a "helluvah-magnet" above your coil, way stronger than the common ceramic ones? Right on, more bite, and wider frequency response. Super-Hot Pickups no more need to sound lifeless. Crystal clear and articulated sounding pickups with high output.
The first HDN I bought was installed on my ST Weaver (photo) and this link goes to a page with a review about this guitar, with tech specs and samples of the HDN if you want.







Neck Pickup:

I've already used some pickups made in my country, bought some, sold some, kept some. The AlNiCo Dallas set I use on my  ST Nevan strat is, for now, a keeper example.
I read a lot of  Paula Bifulco and Paulo May and I deeply respect their experience and knowlege, they made some nice reviews of  Sergio Rosar pickups, another national manufacturer, and decided to try 2 of their neck models for this project, "Virtual Active" and "PunchBucker".
I need to tell you that this man gives lots of useful info about his pickups on his website, with frequency response analysis, resonant frequency, DC resistance and Inductance as well. I want to disassemble this pickup and wind a "sustainer coil" along with the existing one without damaging anything.

Sustainer:

So, I need to thank this person, Mr. Sergio Rosar for listening to my idea for the design and hacking his product and being so kind to send me the piece with a bobbin disassembled already, as well as all the knowledge about electromagnetism and what could or should happen once my new coil was put in place.
You can see the result on your left side, the hacked pickup already with a base and the new sustainer coil ready to be reassembled, soldered and installed.
I already written an article, funcionamento do sustainer and if you don't know much about it maybe you can get a thing or two there.
I've already prototyped some sustainers but never attempted the "sustainer + working pickup" thing and even though I think (or hope) it's gonna work, that's new. If it works, you'll soon be reading another article here named "DIY Sustainer" and you'll know what's this one about, right?

Electronics (analog):

On the analog side of things we got 2 electric pickup volume controls going to a switch. The piezo goes to a "Blend" control to set the mix with the electric signal on the main output. The second output is for the acoustic signal and the "Blend" control do not affect it, so it can go straight to a second fx chain, a mixer or another amp.
The fourth pot sets the amount of signal going to the sustainer. From "organic sustain" to "all-out-morello-like-crazy-feedback", everything in between is possible.
Since I do not realy use a passive tone control, I won't be using one. In fact I have made a presence control to do add more presence on another guitar, the ST Vic and and let the EQ for my rig to take care. The pickups are passive but there`s a whole preamp and signal routing system onboard.
(Note: The picture is not my preamp, it's still under development)

Digital stuff:

I'd like to talk about the proximity sensor and the IMU before giving you more details about the STG-O.S.
The guys from Zvex used capacitive distance sensing for Wah Probe and Fuzz Probe like an expression control. There are some keyboards using IR and ultrasonic range sonars for this purpose too, so, why not put something similar on a guitar?
 My sensor of choice was a SR-04 ultrasonic sensor. It's cheap and do not suffer light or electromagnetic interference. So I could move my hand in front of the sensor to control a midi CC parameter that gets higher as I get closer.
 I.M.U. stands for "Inercial Motion Unit" and it takes care of measuring linear and angular acceleration with an accelerometer and a gyroscope on 3 axis for 3 dimensions. Some IMUs are even more complex with magnetometers and other things, but this one just gets the processor to know the orientation and acceleration of the guitar, so the values can be used to control effects. That one is really experimental and still need a lot of test.

STG-O.S.

It stands for "Sharp Trickster Guitar Operational System". I see Mathew Bellamy (Muse) and others using Kaoss Pad on their guitars and think It`s a nice idea, but guitars could have way more powerful and capable digital interfaces, so I started building one by myself with everything my mind came up with.
The "XY Trackpad" function is a keeper but I could control my whole gear with my hand, switching stompboxes on and off, changing my amp channel, having more input devices like the distance sensor and IMU and doing lots of great stuff with MIDI protocol, standard for most rack gear, VSTs and everything.

Recursos atuais:

- Rig Mode: A virtual pedalboard with 10 stombpoxes and 5 footswitches to control an analog midi-enabled gear on a rack or a Midi-Looper or a VST like Guitar Rig or Amplitube.
  
- XY TrackPad:Gets X and Y coordinates when you slide your finger (or pick) on the screen and convert to Midi-CC values (0-127) to simultaneously control 2 parameters for vertical and horizontal components.
 
 - Function Generator: This one is capable of generating wave patterns like sinusoid, triangular and sawtooth as midi CC and showing it real time on an osciloscope screen. It works like an external LFO for any pedal, parameter or unit on the gear assigned to it.

-Piano Keys:A keyboard (as the name implies) for controlling accompainment key or setting a latching bass synth, drone or anything your VST can. It's possible to play lead but it would need a nice coordination. There's a transpose function for semitones and octaves up or down the middle C.


 Quick Demo:

To-Do List:

As I said, even a High-Tech hard-case is on my list of things to do and I'll write about it as soon as it's finished.
The OS is getting written and improved on a daily basis and I'm looking for new functions before taking it as a definitive v1.0 firmware ready to go onboard of the ST Warlock.
One thing I'll like to try is DSP but the latency and AD and DA converters quality would be a major issue here, I'd probably need another board for this one. With this one I could try audio>Midi conversions, like the Roland GR gear but It would still be monophonic.
Another thing I could do is to generate digital drones or re-create the audio sensed undersampled and injecting it on the sustainer driver for a synth feel or another weird effects, maybe? Lots of possibilities here, so I need some more time to run these tests and find out what's possible.
I invite you to follow this project development on my blog, I'll write new posts every time I get something new to show you. Feedback and suggestions would be much appreciated too! If you have some function you would like to see on STG-OS you can leave a comment bellow. If you'd like to sponsor or help this project it would be nice!