Welcome to the Mega Drone Synth build instructions. The circuit construction is fairly straightforward, but it will require some patience when we get to the wired components (there are a lot of them)! Let’s get started!
Before beginning any circuit-building project, always ensure that you have all of the parts required to complete the circuit. Check your kit parts against the Mega Drone Synth BOM.
If you are missing any components, we will send them to you free of charge.
Let’s start with all of the components that are soldered directly to the PCB.
ICs and Resistors
Insert the 4 555 timer ICs and the 4093 IC into the PCB. The IC half-circle notches should all point to the top of the PCB. If the ICs do not fit, gently squeeze the leads inward. The 12 1kΩ resistors are also placed onto the PCB at this stage. Solder all of the components onto the PCB.
The next step is to add the capacitors. C1-C4 are polar electrolytic capacitors and require proper placement for the circuit to function. Note the black band on the body of the capacitors. The lead closest to this band is the negative lead and should . Insert this lead into the circle through-hole and insert the other lead into the square through-hole with a ‘+’ symbol underneath.
C5-C8 are non-polar ceramic capacitors and they can be placed onto the PCB without worrying about which lead goes into which hole.
LEDs and Transistors
The LEDs D1-D4 are polar components and need to be placed properly. Look closely at the body of the LED – the flat edge identifies the negative lead. The negative lead will also be shorter than the positive lead. Just like the electrolytic capacitors, the negative lead will be placed into the circle through-hole and the positive lead will be placed into the square through-hole. If you are going to put your circuit into a case, you should use wires to extend the LEDs from the PCB.
The transistors Q1-Q4 are marked with a silkscreen circle shape with a flat side. Look at your transistors and notice how the body shape is similar – they will be inserted with the flat side facing to the right. Spread the leads out gently to fit them onto the PCB.
That’s the end of the first part of our build. The rest of the components will be attached to the PCB with wire.
Our first components to be added to our circuit are the potentiometers. Note that your kit has two different valued pots – POT1-POT4 are 50kΩB and POT5-POT8 are 1MΩB. Make sure that you use the right pots!
Look on your PCB and notice how the silkscreen has a ‘1’ and ‘3’ outside the rectangle for each pot. These identify which wires from the potentiometer go where (see picture above).
I suggest soldering wires to your potentiometer before adding them to your PCB.
For POT5-POT8, the wiring is different from the other pots. You will have to connect solder terminals 2 and 3 with wire (as shown in the picture above) or by making a solder bridge on the bottom of the PCB. Solder bridges are prone to having connection issues, so we recommend using the wiring method. Connect the wires running from solder terminals 1 and 3 to the designated positions on the PCB.
The next wired components to be added are the switches. There are 16 switches, so this step will require quite a bit of time. S1-S4 & SW9-SW16 are SPDT switches (3 solder lugs) and SW5-SW8 are SPST switches (two lugs).
Just like the potentiometers, the switch silkscreens are numbered on the PCB. When inserting the SPDT switches, make sure that the wire running from the middle solder lug is inserted into the middle hole. The other leads can be inserted into the remaining holes without worry about placement.
The SPST switches are just on/off switches, so their PCB placement does not matter. Make sure that the same solder lug on all the switches goes to the same numbered hole. This will make mounting the circuit into a case much easier, as all the switches can be oriented the same direction.
Solder wires to the switch solder lugs before you place them on the PCB. You might find it easier to work with an assembly-line flow when you do this step. There’s a lot of repetition!
The last step is inserting all of the jacks onto the PCB.
The first set of jacks are the 3 1/4″ jacks (Clock In, Out, and CV In). Solder wires to the 1/4″ jacks before attaching them to the PCB. In the picture, the red wires are tip connections and the green wires are the sleeve connections. Tip connection wires go to the square through-holes and the sleeve connection wires go to the circle through-holes.
The 9V battery jack’s red wire is connected to the PCB at the circle through-hole and the black wire is inserted into the square through-hole.
There are three solder connections for the DC Jack, center pin (‘P’), sleeve (‘S’), and connect (‘C’). On the PCB, note the square and two circle through-holes – the square is for the center pin connection, the middle circle is for the connect connection, and the rightmost circle through-hole is for the sleeve connection. See the picture above for solder connection identification for more detail.
Congratulations, you’re done building your Drone Synth! Now make sure it works! Put a battery in your circuit, put a 1/4″ plug into the ‘Out’ Jack and an amplifier, and see if the LEDs light up and the circuit produces some noise. If nothing happens, don’t panic! You may need to flip the switches and manipulate the potentiometers to get the circuit to circuit work at first. Do this for all of the rows of switches before doing anything else. If this does not fix your problem, double-check your power connections. If this still does not fix it, go back through the circuit and ensure that everything is inserted and soldered correctly.
Thanks for following these instructions. If you have any questions about the assembly, feel free to shoot us an email; we’ll update the assembly instructions to make it easier to understand. Have fun making some crazy noise with your hand-made 4093 Drone Synth!