Infinite Response are now taking orders for VAXMIDI, which they describe as the world's first Open Source MIDI keyboard with semi-weighted hammer action keys,hi-res velocity, polyphonic after touch and release velocity. Here's the details in their own words...

VAXMIDI is less than 1/3 the price of our first product, the VAX77. This low cost is only possible because we ask that you perform the final assembly yourself. Review the assembly instructions; the only tool you need is a screwdriver. It is not a difficult task but you will have to dedicate several hours to the project. Take your time, build it with care and you will have a rock solid instrument that will last decades. It was designed to be maintenance free but easy to modify with future enhancements from Infinite Response and other members of the VAXMIDI community. We plan to strongly support the community with forums for building VAXMIDI, accessorizing it, and supporting software developers that want to add new capabilities to VAXMIDI. Join us.

VAXMIDI began as a Kickstarter project on March 31, 2015. About 100 backers funded the development anticipating that they would receive a remarkable MIDI controller a year later, or eventually. Several of the backers offered their expertise as members of the VAXMIDI Design Group and recommended many of the features present in the product today. I thank them all for their wisdom and guidance. Some of the features added cost to VAXMIDI and the retail price is higher than our original target. Nevertheless, this is remarkable keyboard that will get better every year as members of the VAXMIDI community offer accessories, improvements, and enhanced firmware.

The price/performance of VAXMID is possible because of two critical design parameters. The first is that it is comprised of 2, 3 or 4 identical dual octave modules. This created economies of scale never available to a MIDI controller at the expense of not having traditional keys at either end of the keyboard. VAXMIDI starts with F on the left and ends with E on the right. (You will be able to change that to C to B once an additional part is designed later this year) That part will be free to backers and early purchasers.

The second design parameter is that it is assembled by the end user using only a screwdriver. This was a difficult achievement but essential to controlling the final cost. We estimate that it will take 4 hours to assemble VAXMIDI, although I can do it in less than an hour with all the practice I've had over the last few months.

Irrespective of cost, the reason VAXMIDI is a great keyboard is because of the sensors. I would not have embarked on this journey if I hadn't discovered them. They measure the keys more accurately, with less power, and at a lower cost than any sensor I have ever evaluated. Unfortunately, there is a 37 week lead time to get them.

Key sensor technology
The microprocessor clocks the sensors at 200 KHz which is 5 microsecond resolution. The U shaped sensor from Vishay Semiconductor has an led on the left wall and a .3 mm detector slot on the right wall. The wing of the hammer flies through the sensor when a key is pressed. When the notch crosses the path of the led, the detector measures the length of the pulse to determine the key velocity. Notice the triangular window beyond the notch. It is in the detector path when the key is depressed and when the key is pressed harder the hammer moves and lets more light hit the detector. That is how polyphonic after-touch is generated.

We were able to secure enough sensors to build 200 VAXMIDI keyboards and after we ship to our 100 backers, we will ship the remaining 100 in April to customers who preorder now. Once those 100 VAXMIDIs are sold, we plan to order sensors for the next production run for retail delivery in December 2016.

Those 100 units for sale include 15 four octave version, 50 six octave versions and 35 eight octave versions, about equally divided between black and white.

Pricing and Availability:
VAXMIDI ships April 2016
4 Octave: $649
6 Octave: $899
8 Octave: $1149

More information:

• VAXMIDI

• WNAMM09: Polyphonic Aftertouch In a Folding Keyboard 29-Jan-09
• The Keyboard Roadies Dream 31-Oct-07