How to build a midi controller - DIY virtual analog controller.

I haven't posted on this blog for a while. Busy with my day job and have been out of project funds for a while. I've been kinda quite on the gear building front. But, with Christmas holidays and a little overindulgence, I have found myself with some spare time to build a box or two for next years projects. Something that is quite new for me and has been taking over my music composition fancies is a little application called Ableton Live 9. Being a staunch Pro Tools user for the past 15 years has taken its toll, and to be honest this new (for me), "non-linear" way of making music is causing me to once again gain real inspiration from a piece of software. So I decided to build myself a small midi controller for the purpose of servicing some plugin EQ, compression and synth parameters.

Things can become very cramped on the Breakout Shield 

The Basic Concept of this controller.  

The concept for this controller is quite simple. I have in the past had some serious problems coming to terms with the idea of software controls when adjusting EQ and compression settings while using a mouse. I have always felt that something major gets lost when adjusting parameters on software when compared to hardware. Hardware for me, force's me to listen to adjustments rather than subconsciously relying on visual feedback provided by modern software signal processors. For me, eq'ing with a mouse while staring at a spectrum analyser causes me to second guess my instincts regarding treatment of a selected instrument. I have tried several controller solutions, the knobs on my Novation controller keyboard, the knobs on my mackie HUI all provide control over my parameters, but the lack of friction on the pots and the endless rotary feeling really gets in the way for me. It doesn't feel like I'm using an analog processor. It doesn't bridge the gap between analog and digital. I used to argue that digital processor plugins will never sound as good as hardware, but recent experiences have caused me to think twice about this statement. If I could control a plugin in the same way I control a hardware unit, then perhaps I can start using my instincts again and not rely on finicky mousing around or ultra-light and unresponsive endless rotary encoders. 

Cut off the excess pot pole with a hack saw or a mini cutting tool so you can fit the knobs. 

The design for this controller is very simple, it will feature 16 analog pots arranged in a specific way on a 3U front panel that can either be placed (At an angle) on your desktop or racked in the same space as all your analog processors. I will be using 24mm, 10K potentiometers and Urie 1176 reproduction knobs. Basically its a USB plugin controller masquerading as a vintage analog processor. The central processing unit I will be using  is from Livid Instruments. Its their smallest brain unit which supports up to 16 analog inputs, 16 digital inputs, and will also support a number of LED's. I could if I wanted to, include push buttons and LED's, but have decided to keep this controller very simple. I have some plans brewing for a much bigger unit that will feature 24 faders, mutes, pan's and sends. This Analog Control unit will consist of 12, 4x3 control knobs arranged in similar way to an analog equalizer. Each pot will sport a small reproduction 1176 knob.  The remaining four knobs will feature large 1176 knobs, these 4 controls are arranged in a 2x2 configuration, for compression control and general synth parameter duties. One of the main features of this unit is that you can rack in in a standard 19" rack unit, or stand it on your desk within arms reach. With the unit placed in the rack, you can get a feeling of it being an analog unit, as it sits comfortably amongst all your real analog hardware.  You could  very easily create any configuration you please, most midi brains on the market will support a range of control components including proximity sensors and joysticks. Really, your imagination is the only limit.

Disclaimer: Remember! Parts can cost a small fortune, and it is valuable to know that building your own is often not cheaper than buying from the shop. Also, this is DIY! There is always a chance that you can mess this up.  If you do, no one will care. And you wont be able to return the used parts to the shop. So if your looking for an easy and cheaper alternative to buying, think again. This controller cost me around 3 times more to build than the Novation equivalent with the same features. Sometime's its easier to just buy the bloody thing! But, if your willing and able. This type of DIY project can be really rewarding and will leave you with a very high quality and unique end product that you can use for years.    

Enough rambling, lets get on with how to build this thing.

Shopping List  

For this project you will need

• Midi Brain processor (USB, see info below) 
• 16 x 10k audio potentiometers.
• 16 x 0.01uf capacitors (Ceramic) 
• Hookup wire (3 colours) 
• 16 knobs
• 3U aluminium front panel 
• Some wood of some description for the table stand (Optional) 
• Adhesive Rubber Feet   

Tools

• Soldering iron 
• Side cutter's
• Needle nosed pliers 
• Counter sink bit (Optional)
• Drill (Preferably a drill press) 
• Hack saw or Dremel with Cutting disk. (for the pot shafts) 

The Midi Brain. 

The first thing your going to need is a brain. The midi brain is basically the central processing unit that will convert your analog control signals into midi "cc" (Control Change) messages that are sent to your computers sequencing software via an on board USB facility. With most midi controller brains, you can connect a range of analog peripherals by soldering them directly to the brain board or connecting them via ribbon cables. There are a range of controllers on the market. I would not know about, or recommend building a brain from scratch, I can only imagine that you would need some kind of advanced degree in digital system processing and programming or some such to pull that out of your hat. So leave the real work to the experts. I have listed the ones I am aware of below. 

1. Livid Instruments Brain Jr 
2. Livid Instruments Brain V2
3. Doepfer USB64    
4. Hale Micro UMC32 (Always seems to be out of stock) 

Be aware that these brains support varying levels of features. The Doepfer USB64 for instance supports upto 64 analog cc's and the Brain Jr only supports 16. So do some research before deciding on the right unit for  your particular project.

Brian Jr and Breakout Shield

What they look like conjoined

For this project I have decided to use the Brain Jr from Livid Instruments. The bran Jr is just under $50, supports 16 analog cc's, 16 digital cc's (Push buttons) and 16 LED connections. I could connect the pot's directly to the brain itself. But as far as permanent connection is concerned, I decided to order a "Brain Breakout Shield" which would allow me to solder the connections directly to a separate PCB that connects directly to the brain. This is a good idea if you ask me. The first time I tested the brain, I didn't use the shield the the wires kept falling out. So I was very glad that I ordered it, it was only and extra $17.50 and worth every cent. Lastly, I will be attaching the Brain to the rear of the front panel using four 3mm adhesive stand-off's. 

The front Panel. 

I thought that the easiest and most practical control surface would be a 3U front panel. I also decided to make some legs out of some scrap plywood I had lying around. This would allow me to use the controller on my desktop and in my rack. I drilled four holes in the front panel to attach the legs and used a counter-sink bit to make a nice finish when inserting the screws.  

The Finished Controller without the knobs. 

Connecting the Potentiometers (Where do I put the Capacitor?) 

The only potentially confusing part of building this thing is where to put the caps. After some digging around, it soon became clear and easy. You will need a 0.01uf capacitor and you will want to connect it between the wiper (Center) and the Earth (Right) on each and every pot. I connected mine directly to the pot itself then soldered hookup wire on the each lug, twisted for neatness and to save space. I then soldered the hookup wire directly to the corresponding pad for each potentiometer on the breakout shield. 

  

It does tend to get a bit cramped around the pads on the breakout shield, there are methods of reducing this amount of wiring by using a common ground instead of routing all of the grounds from the pots individually. I decided to do it the long way, since this is my first controller. But with some care, some nice thin hookup wire and some cable-ties its easy to keep things nice and neat. You are not just limited to pot's. You can connect a range of devices to the brain. You could even create a midi controller using proximity sensors, ribbon strips and joysticks.  

You can neaten things up with cable ties.

Knobs

I really felt that this area was an area of great importance. If I want this controller to feel like a high quality piece of analog gear, I would need to invest in some serious knobs. This would ensure a nice high quality look and feel. I settled on some reproduction  1176 knobs from Hairball Audio. I have used these knobs in the past on the Hairball FET compressor I built last year, so I know exactly how good they feel. It wasn't until I actually fitted them to the unit that I realized how good they look too! They have really made this unit what it is. I'm very glad spent a bit of money here. 

Getting it all to work with your PC

One of the reasons I decided on the Brain from Livid Instruments, is the reputation they have for their configuration software. The Brain Jr uses the same configuration software as the larger Brain V2. And it is easy to customize your parameters as well as enable and disable controls. I found it easy to setup and test my new controller using the tools available in  the software. Just remember that you will need to close the brain software before opening Ableton Live, it seems that you can only run one or the other. No worrier tho,, you can save your settings to the brain so it will remember its own configuration for the next time its plugged in. Getting the controller to work in Live 9 was as easy as any other controller and has integrated very nicely into my workflow.  

And she lives!

Final thoughts.

I set out to create a midi controller that makes using plugin EQ and compression more analog buy providing real analog controls that are assignable to software parameters. To be honest, I think I have achieved that and much more. After using this controller for a few hours, I found myself using it for just about everything. Synth parameters, parametric EQ's, compressors, even pan and faders. Its amazing! Really, Its one of the nicest things I've ever built and I'm extremely happy with it. I'm really fired up to build a "virtual analog mixer" now. If I was to change anything? Well, I think the payout works really well, so I wouldn't move anything. I would however include a few push buttons for band bypass switches and such. You know what? I could always add that at a later date. For now, I have a new best friend.  

Notable Alternatives

Novation Launch Control features 16 knobs, 8 launch  pads and is bankable. 

Buy the Novation Launch Control: Click here (Amazon.com)

 

Akai MPD26

This is more of a drum pad controller, but it does feature some really nice pot's and some faders. I havent suggested the MPD32 because I have had issues getting it to map properly with Ableton Live 9. The MPD 26 on the other hand works like a bomb. 

Buy the Akai MPD26 now Click here (Amazon.com)