IntroductionThe Kurzweil K1000 is a classic synthesizer series that was produced from 1988 to 1992. It was made in two formats/versions: keyboard and rack.Even today, there's a good number of musicians keeping it in the studio because of some incredibly good (even for today standards) multi-layered sounds the machine can produce.One of the recurring problems with these synthesizers (both in keyboard and rack form) is the display electro-luminescent backlight running out.In this Instructables I will show you how to replace the factory Kurzweil K1000/1200 series display with a modern LED backlight LCD display. This will keep your synth usable (and attractive).I will also share with you a PCB to speed up the replacement process.Let's go! :)Seiko M1632 Vs New HD44780 DisplayThe factory display Kurzweil installed both in K1000/1200 series sinthesizers was a Seiko M1632 display.This display is based on an Hitachi controller (ASIC): the HD44780. This is still used today on those displays commonly used for DIY project.The main differences between the Seiko EL backlight display and modern LED backlight display based on HD44780 are:- Pinout: the two displays have a different pin position and pinout (signals are the same however)- Backlight: the old backlight was electro luminescent (EL), while the new one is LED. This asks for contrast control and a different voltage.- Phisical: the new display has different dimensionsIn the following we will find a solution for every single difference.Pinout and BacklightLook at the pinout comparison. With the exception of the backlight, all the signals (voltages and data) are the same.The only main difference is the physical pins position.For what concerns the backlight, the new display asks for a contrast control. This can be achieved with a simple voltage divider.To help in this part of the project, I have realized a PCB with screen printed pin positions. Simply solder cables straight from the new display pins to the corresponding PCB pins and you are good to go.The board also hosts the contrast voltage divider the LED backlight asks for.Please notice that the PCB is double-faced. Populate the board accordingly to the type of K1000 (keyboard or rack) you are going to install it into!Warning! Kurzweil K1000 keyboard and rack versions have reversed pinouts. The PCB must be assembled in the right direction for the synthesizer type you are going to install it on.Warning! By connecting a K1000 keyboard to the PCB assembled for a rack version, you will fry the display. It will go very hot and it could injury your skin in case of contact!New Display Physical ModificationsThe old, factory, Seiko display and the new one are physically different.Installing it in a K1000 keyboard or K1000 rack asks for cuts on the new display board, at different positions. In particular:- K1000 keyboard: cut the bottom part of the display PCB- K1000 rack: cut the bottom part of the display PCB and both sides.I used a mini driller with a little grinder on top for this operation.In case of the keyboard version, you will additionally need to drill three mounting holes, or glue the display onto the original synthetizer display board.In case of the rack version, the only method I could think of to install the new display was the use of hot glue and some 6 mm spacers. It works well and don't ask for irreversible modifications to your valuable instrument.Warning! While drilling PCBs always wear mask, protective eye glasses and gloves. A lot of dust will be produced. The drilling operation is dangerous also because of the small dimension of the display.

DIY Korg PME40X External Selector "Clone"I am a PME40X user, and I like this multi effect very much. Sometimes I feel the need to place an external stompbox in my effects chain, but this is not possible without the external selector Korg realized for this pourpouse.I have not one of these at hand, nor schematics unfortunately, but, as you can see, Korg placed some useful indication on the module front, soo..... let's go and realize a replacement for this!Modules PinoutFirst thing first, we need the pinout for these modules in order to make good use of signals coming from and going into the power supply / FX selectors base.The most important thing to notice here is that the power supply is +15V, not the now "standard" +9V. This means that we cannot power most of our external stompboxes directly, but they will need a separate PSU.Hardware and Assembled ModuleThe module in a nutshell is a pair of unity gain amplifiers, one at the module input, the other immediately after the return path. It uses a very small amount of cheap and common components, the op-amp being the "prom Queen".Even if the module is simple, cutting a perfboard to the right size and then soldering the nedded components following a scheme could be time consuming. It's way better to have a pre-sized module manufactured and then solder some component, is't it? :)The components you will need to assemble the module are (BOM):1x External Selector Module PCB2x jack socket, 6.3 mm, mono, female1x 8 pin precision socket1x op-amp (NJM4558 or any other pin compatible4x 1M ohm resistors2x 0.1 uF poly capacitor2x 10 uF electrolitic capacitor8x angles pinheadersI think the module looks good, but most important: works great! I tested it with different amplifiers, and they all worked well: NJM4556, NJM4558, TL072 and NE5532. Even if some amp could be better on paper for audio use, in this application I couldn't honestly hear any difference between those I tested: the module is always quiet and "transparent".The module PCB you can see in these pictures has been manufactured and sponsored by those nice guys at PCBWay - PCB Prototype The Easy Way. Their customer service is very good and PCB quality excellent. Thanks guys!The module was designed and sized around my PME40X. It's tested, so don't worry!Final WordsThis was a simple project because simple is the module's function. As I said I have not an original Korg external selector and it would be interesting to see what's "hidden" under that plastic box. In case anyone has one, or schematics: please post a pic or a link!Now, having the pinout opens a lot of potential for DIY project: I hope some of you will chime in with brand new exciting effects for our beloved PME40X!

The Redox is a keyboard project designed with ergonomics in mind. It uses Cherry MX style mechanical switches laid out in a 7x5 columnar stagger layout with components that can easily be sourced.The design was heavily inspired by the Ergodox keyboard, and its main goal is to reduce the size without sacrificing too many keys, hence the name Reduced Ergodox.As an Ergodox user I couldn't ignore the few flaws of the original design and in a moment of arrogance I tried to fix them, thus the Redox features:Easier to reach thumb cluster.Additional easy-to-reach rotated 1.25u thumb key.Reduced size.Reduced costs (the Redox uses Arduino Pro Micro instead of the Teensy 2.0).Either half can be plugged in to the PC since each half can act as the master.Either half can work as a standalone keyboard to be used as a macropad/gaming keyboard.RGB backlighting support.3D-printer friendly case.WirelessVIA compatible (thanks to Harshit Goel)More info at: https://github.com/mattdibi/redox-keyboardThese Gerbers refer to the receiver only. To make a working keyboard you need also two Redox Transmitters PCBs. Please refer to the documentation for more informations.

The Redox is a keyboard project designed with ergonomics in mind. It uses Cherry MX style mechanical switches laid out in a 7x5 columnar stagger layout with components that can easily be sourced.The design was heavily inspired by the Ergodox keyboard, and its main goal is to reduce the size without sacrificing too many keys, hence the name Reduced Ergodox.As an Ergodox user I couldn't ignore the few flaws of the original design and in a moment of arrogance I tried to fix them, thus the Redox features:Easier to reach thumb cluster.Additional easy-to-reach rotated 1.25u thumb key.Reduced size.Reduced costs (the Redox uses Arduino Pro Micro instead of the Teensy 2.0).Either half can be plugged in to the PC since each half can act as the master.Either half can work as a standalone keyboard to be used as a macropad/gaming keyboard.RGB backlighting support.3D-printer friendly case.WirelessVIA compatible (thanks to Harshit Goel) More info at: https://github.com/mattdibi/redox-keyboardThese Gerbers refer to the transmitters only. To make a working keyboard you need also a Redox Receiver. Please refer to the documentation for more informations.

KeyBoh is an Arduino Leonardo shield having 20 buttons, one analog thumbstick (+button) and one rotary encoder (+button), so you've a total of 22 buttons, a joystick and an encoder.You can use the standard Arduino Leonardo USB libraries or using other, more feature-rich libraries such as the HID Project by NicoHood.In the Github Repository you can find the schematic, the STL files for 3D printing the faceplates, and a programming example.Used joystick is like the PS2 type, base measures about 26x21mmYou can found more pictures here

The Yampad is a Macropad/Numpad which uses Cherry MX style mechanical switches laid out in the usual numeric pad layout. The only difference comes from the bottom row, which uses a 4 keys configuration, thus enabling the use of the macropad as a nav cluster.The name comes from the acronym: **Y**et **A**nother **M**echanical num**PAD**, referring to the disruptive and innovative nature of the project.The main goal of this project is to have a cheap, easy-to-build, feature-rich numpad which is completely open source.Features:- Cheap to build: the PCB can be manufactured for less than 1$ per piece.- Easy to source components.- Easy to build.- Hot swappable keys using *Kailh PCB sockets*.- Arduino Pro Micro powered.- QMK compatible.- RGB backlighting support (optional).- OLED 0.91" screen (optional).- Completely open-source.

### DESCRIPTIONMy first attempt to build a board for a vintage computer Amiga 1200 to use an external Commodore Keyboard (A2000, A3000, A4000)### TECHNICAL DETAILS / COMPONENTSSimply piggy back the socket into U13 MPU Keyboard controller, plug in some cables and connect a DIN or MiniDIN female port. That's all, folks!### LEARN / TOPIC / BUILD INSTRUCTIONSI refuse to refund any damage or bad connected motherboard or computer. Do this at your own risk!