This is simple project to make Power Supply efficient enough to power up many devices like synth from one source. This means to free up space used by many power bricks for every synth, drum machine or sound effects. Most of the sound gear use 9V, some use 12V and other 5V from USB, so there is a problem with a lot of tangled up cables with different socket types.
I have unused laptop power brick that has around 16V and 5A on the output, use couple of power regulators to get down to 12V, 9V and 5V. I used one 12V 2A power regulator because I have only one device using that voltage, so that is plenty enough. But I have a lot of gear that use 9V with different polarity on the sockets, so I used three 9V 2A power regulators. There is also couple of small ceramic capacitors on every output of the power regulator, and one on the input. They are around 22pF, smaller the better and less noise 🙂
USB powered devices doesn’t need a lot of Amperage so we use one 1,5A 5V power regulator connected to two double USB sockets, so we can connect 4 devices. In addition to that I decided to add on 2 unused data lines on the USB (there are 4 pins, 2 for power and 2 for data), a CV and Gate signals to control my modded Monotron and Monotron Delay synths. So we need to add two mono mini jack sockets to get the signals from any sequencers and pass them to one of the double USB sockets. It’s important to not connect devices that use data to this USB sockets!
Now we can connect power leads, In my enclosure I can fit inside 6 leads on both sides. That give us power to 12 devices + 4 USB! Cut some slots on the walls of the enclosure to make some strain relief.
As you can see this is a tight fit, not much room inside, so we need to isolate every connection to prevent shortage. There is one thing to remember, power regulators by decreasing power down, produce a lot of heat! I added some kapton tape (heat resistant) to the cover that is touching the regulators to not to melt the plastic.
Now we have on one side, six 1.7mm plugs with 9V that we can use to connect up to 6 Korg Volcas! On the other side we have 6 standard sized plugs, one 12V, two 9V with positive inside, negative outside polarity. And three plugs with reversed polarity, negative inside, positive outside.
I have added some stickers to cover some scuffs on the enclosure that I scavenged from somewhere, and added some markings with a Sharpie to know what the voltage and polarity is. Circle with + inside means, ground (negative) outside of the plug barrel, plus (positive) inside.
The kapton tape wasn’t enough, and power regulators was overheating so I added some additional aluminum radiator plate and drilled much holes to desepat the heat.
Now to the Monotron Mods! I simply reused two free wires from the powering lead that I have already implemented to power my Monotrons from the USB. You can see how I did it on my Monotron Duo Mod here.
Monotron Delay CV signal goes to the Pitch pad on the PCB, Gate has its own pad 🙂
The same thing on Monotron, CV goes to the Pitch pad on the PCB, next to the Gate, GND and VCC pad.
Simple!