Soldering the components

Now you know how to solder, let's put it to the test. Ready?

Part one - The headphone jack

Before soldering, please check our video tutorial again to ensure you're doing everything right.
The first components we'll use are PCB and headphone jack.

The headphone jack will be placed at the upper left part of the PCB. You can help yourself by finding the little square.
Or, you can simply check the photo below:

Make sure that the round part of the headphone jack is facing up. That way, you'll be able to connect your headphone jack to your headphones.

While placing it on the board, check if everything is well-adjusted before soldering.
Your Synthia should look like this by now:

Now is the time to take your soldering iron and get down to business. 

Turn the PCB around, find the pins that belong to the headphone jack, and solder them.

Solder all of the pins from the headphone jack and that this component is vertical to the board.

Great job! You successfully soldered your first component! We have many more things to solder ahead of us, so we better hop to the next component. 

Part two - the speaker connector

The next thing we'll solder is the speaker connector. That is the little white thingy you got in one of the plastic bags.

You need to put the speaker connector here.
Take your soldering iron, turn over the PCB and start soldering.
Beware not to solder the chip near the pins on the front side.

Part three - pushbuttons

Now is the time to solder the pushbuttons!
Buttons are the most commonly used input, and there are a total of 5 of them.
The buttons consist of two parts - the mechanical button parts and the button caps. Buttons can work even without the caps, but pressing them with the caps on feels way nicer, and they look a lot cooler.
However, we'll leave the caps aside for now and focus on soldering the mechanical button parts.

The five buttons will go on five white-marked squares at the bottom of the PCB.
You can check the exact place to put them on the photo below:

The first thing you'll have to do is place every single one of the pushbuttons onto the board. They should be placed vertically on the board.

Before soldering the pushbuttons, make sure they are perpendicular (vertical) to the board. This is very important as you'll have trouble putting the protective casing on the device if the buttons are tilted.
After placing the components in the right place (pins through the tiny holes), put the main board on the surface in front of you and pick up the soldering iron.

Solder all five pushbuttons, and make sure they are vertical to the board.
Also, now is a good time to check if there is any solder bridging.
After you finish soldering those five pushbuttons, this is what the back of the PCB should look like.

And the front:

Part four - encoders

The next thing we'll solder is two encoders.
Those are similar to pushbuttons, but they are round and a bit bigger.
Here are the components that you'll need for this step. Got everything? Cool, let's start!

Start with inserting the first encoder. As you can see in the photo, each rotary encoder goes where the white square is shown on the board - it's hard to miss it.
Also, keep in mind that all pins must be inserted into the holes to solder the encoder to the board later. In case any of the pins bend when inserting, simply
straighten them out with your fingers and try again.
There are seven pins on each encoder arranged so that there is only one way to insert it. After inserting the first rotary encoder, repeat this step six more times.

Make sure encoders are vertical to the board before soldering.
If everything seems alright, start soldering!

Part five - sliders

It's time to solder the sliding potentiometers. They are crucial components that will later be used for playing with sounds.
There are two sliders, and each slider has three pins that need to be soldered to the board. One pin is on one end of the slider and two on the other, so you don't have to worry about aligning them the wrong way.
They should be located above the encoders.

Place it on the right spot, and start soldering!

As previously mentioned, there are three pins on each slider. Fit the slider so that the two pins on one side go into the two holes on the PCB board, and one
pin goes into the single hole on the other side of the PCB.
After inserting the first slider, turn the board upside down and solder the three pins.

This is what your PCB should look like after soldering the sliders.

And the back:

Congrats! You successfully soldered all of the components!
The hard part is done. The only thing left to do before connecting Synthia to the PC to check if everything is soldered properly is to connect the speaker!

We hope you had a great time soldering the components. Sadly, you'll have to turn off your soldering iron now, but there are fun steps ahead, and we're not quite done yet! Please turn off your soldering iron by unplugging it from the power outlet. Leave it on the soldering iron stand for at least five minutes so it cools off before you put it away.

Ready to continue?

Part six - connecting the speaker

We have to connect the speaker before doing the hardware test because, without it, we couldn't check the main feature on Synthia - the sound!
You probably already know what does the speaker look like, but if not, check the photo below:

One of the first components you soldered was the speaker connector. That is the small white thing at the back of the PCB.

Take the white part of the speaker and push it into the connector. If the speaker is connected properly, you should feel click!

This is what Synthia should look like right now:

In the next chapter, we'll guide you through the hardware test.