* You should've soldered something before, preferably a small kit. Without some practice you will get problems with bad soldering joints. Errors like this are always very difficult to find if you have not worked properly. Instructions on how to solder and which tools to use can surely be found on the Internet.
* You need time! Someone with a lot of experience and practice can finish the whole kit in 2 hours. But if you don't take enough time, there is a high risk to fill something wrong or to create bad soldering joints.
* You need good tools. Good doesn't always mean expensive. But don't try to work with unsuitable tools, because it may also lead to problems.
* Soldering iron: It is best to use a temperature-controlled soldering iron or a station with about 40 watts of power. Never use soldering tips that are too large or a soldering iron with a large capacity.
The printed circuit board has numerous optional components that only need to be mounted in certain cases. This guide shows you all possible options and indicates whether steps are optional or recommended. All steps without further hints are necessary.
It is also possible to equip the board with a PT8211 I2S audio chip instead of the Teensy Audio Shield. This option is not shown here. If you want to use this option, please take a look at the schematic or ask directly via email or in the forum.
The build process is organized into several steps. Each step is on one page with pictures showing the relevant changes. It is good practise to take a short break after each step. For steps in which you have to solder very much (like the IC sockets) you should take breaks in between.
Be careful when soldering on the Teensy audio board! You should take care not to stay too long on one soldering point. Again, take breaks to let the soldering joints cool, so that the chip on the board will not be damaged.
For the assembly of printed circuit boards you should always start with the flattest components and mount the higher components step by step. On the next pages you will find several steps for the parts in a recommended order.
__Note the mounting direction in the IC sockets: If the board is aligned like in the picture below, the notches of all IC-sockets must point to the left.__
You have to cut the needed number of pins from the long double-row-headers on your own. Only JP4 is needed, the rest are optional signals and ground pins if you want to extend the hardware by yourself. For more information take a look at the circuit diagram.
You have to cut the needed number of pins from the long single-row-headers on your own. Only JP1/JP2/JP3/J7/J6/J17 are needed, but it is recommended to solder the remaining headers as well. For more information take a look at the circuit diagram.
You have to cut the needed number of pins from the long single- and the double-row-headers by yourself. The 2 * 2 pins are optional and only needed if you want to use the option for audio-input. The 3-pin-single-row header on the right picture (for GND/VOL/3.3V) is not needed.
The kit contains 10 wires with open ends. These open ends must be stripped, tinned and soldered. You need 5 wires per encoder. To be on the safe side, heat shrinkable tubing should be put over the soldering joints. For this you have to cut 10 pieces out of the long shrink tube.
__Note the direction in which the two ICs must be inserted: If the main PCB is aligned like in the picture below, the notches of both ICs must point to the left.__
__Note the direction in which the Teensy must be inserted: If the main PCB is aligned like in the picture below, the SD card slot must point to the right.__ Also connect the USB adapter cable so that the thicker black end of the female connector is located to the right (like in the picture below).
__Note the direction in which the Audio Shield must be inserted: If the main PCB is aligned like in the picture below, the SD card slot must point to the right.__
Connect the audio ports of the Audio Shield to the pin headers on the main PCB. You only need to connect the audio-out port, but it is recommended to also connect the audio-in port. For the wiring look at the wiring scheme below.
Format the SD card as FAT32 and copy the contents of the directory *addon* from the *MicroDexed* directory to the SD card. You can also install your own SYSEX files (or load them directly onto the MicroDexed later). It is important to keep the directory structure: For each bank there is a directory with the bank number as name.
The jumpers are needed to decide which kind of I2S sound chip you want to use and to enable the I2C pullup resistors. To enable them close JP4 and JP5. Then set JP3 to the down position (as seen in the picture below) and leave JP1 and JP2 open.
Now you can try to power up your kit. If everything works, the display should show a short text during the boot process. After that you you should see the bank/voice selection.
This can happen if the contrast of the LCD display is not set correctly. To adjust it you can (carefully) adjust the contrast with a small screwdriver using the blue potentiometer on the back of the LCD display while power is connected.
This may be due to problems with the SD card? The synth will only work if the SD card works correctly. If the SD card is not recognized, the system will stop. Try to format it again as FAT32 and copy the preset data or try another SD card.
The lines on the encoder (on the three-pin side, the lines on the right and left) have been connected to the headers in reverse order. Exchange them crosswise on the main board.
It is also possible that the potentiometer knobs are mounted too close to the encoder. Loosen the screw in the potentiometer knob and push the knob a bit further away from the case. You can also remove it first and try to push the buttons without the knobs.
First check your MIDI wiring. Are you getting signals? The LCD should show a note symbol or a box symbol under the inverse 1 when you press a key. If not, no MIDI signals are detected and no sound is generated.
Did you reset the EEPROM? You may need to reset the EEPROM after each time you flashed the firmware.
Is the volume high enough? Turn the volume encoder (left) so that the display shows you a higher value (maximum 100).
Has the SD card been recognized? You can only hear the sound if the SD card has been recognized correctly. If not, format it again as FAT32 and copy the data or try another SD card.
