Hello, Ujiie here again.
GAIA.
In our last video,
we took a tour of the 64 presets,
and took a general look
at what exactly the GAIA is.
This time, we'll go deeper
into the inner workings
of the GAIA.
This synth follows in the footsteps
of traditional analog synthesizers.
Once you get familar with the way it works,
it is really quite an interesting synth.
First, this section here is quite important.
The Yellow section...
where you find the key three elements:
Oscillator,
Filter,
and Amplifier.
These are the so-called 
Three Major Elements
of analog synthesis.
The Oscillator produces the sound,
it's the source of the sound itself.
This is the place where it all starts.
The Filter processes the sound
being generated by the Oscillator.
The Filter is responsible for coloring the sound,
making it brighter or duller, so to speak.
The Amplifier deals with the amplitude,
or volume, of the sound.
It controls the level of the sound.
The signal path flows from the 
left side of the panel
starting with the Oscillator,
going through the Filter,
then through the Amplifier,
here at the right side.
From left to right.
Also, we have the LFO over here,
which stands for
Low Frequency Oscillator.
just LFO for short.
The LFO generates very slow waveforms,
which are used to add vibrato etc.
you can use it for a variety of things actually.
Ok having said that, let's go
back to the Yellow section here.
Oscillator, Filter + Amplifier.
First, let's listen to the sound as it is.
This is the sound of just the Oscillator.
What kind of waveforms can
the Oscillator produce?
Can you zoom in here?
Here it says 'WAVE', and next to
the button, there are 7 choices.
Right now, it's set to Sawtooth,
all the way at the top.
Which sounds like this...
OK? Technically speaking,
sounds are characterized by
their harmonics, which originate with
a fundamental frequency, then
1st harmonic, 2nd harmonic, etc.
infinite combinations really...
The Sawtooth waveform contains
an average of 
both even and odd harmonics.
Next in line, if you push the button,
we have the Square waveform.
It looks kinda like a square.
And sounds like this...
Compared to a real instrument, 
you could say it sounds like a clarinet.
In contrast to the Sawtooth waveform,
which contains both even and odd harmonics,
the Square waveform contains odds only.
1st, 3rd, 5th, 7th and so on and so forth...
odds only, that's the Square waveform.
This waveform has a duty cycle of
50% positive, 50% negative,
if you look at the panel you'll see what I mean.
Below the Square you'll see PWM,
which is basically a Square waveform,
but you can vary the width of the cycles.
PWM stands for Pulse Width Modulation.
It sounds like this...
You control the pulse width
by moving this slider here
Can you see? This one.
Let's move it and see what happens.
As you move it up, the positive part
of the waveform narrows.
Down, and it widens up.
That's it for PWM.
Next, if we push the Wave button,
we have the Triangle waveform.
As the name implies, a series of Triangles.
It sounds like this.
It's a very key analog sound.
Next, the Sine waveform.
A sine wave is a very smooth waveform.
It goes up and down like this, smoothly.
In Japan it's used to mark the hour.
Right?
They use a Sine wave for that.
The Sine wave has no harmonics,
just the fundamental frequency.
Next is Noise.
Yep, that's noise alright.
If you have all harmonics present,
and all at the same level,
the result is Noise.
Yep. Noise. Last on the list, we have
the Super Saw waveform.
This waveform sounds like this.
The Super Saw produces a very fat sound.
If you take the Sawtooth, at the top here,
and stack it a few times on top of itself,
you end up with this thick sound,
which is called a Super Saw.
Normally, you'd have to have a number of
all producing Sawtooths simultaneously
to get this sound, but here you can do it
with just one.
Let's go back to Sawtooth.
A nice feature of the GAIA, if you look here,
below the Wave button, you'll find a button
labeled 'Variation'.
Let's see what this does
when 'Wave' is set to Sawtooth.
It's lit up red now.
One more push, and it turns green.
Back to normal.
Did you hear how the sound changes?
I'll do it again.
Ok?
Let's try it with Square.
Ok? Subtle changes, right?
So, not only do you have 
the seven waveforms listed here,
but also three variations of each one.
And that sums up the Wave section,
the source of the sound itself.
But we're not done yet.
Let's set it to a normal Sawtooth...
By turning this knob, labelled Pitch,
you can raise or lower the fundamental pitch
+/- two octaves, in 1/2 step intervals.
I'm going to hold down one key here...
To the right of the Pitch knob
is the Detune knob.
Detune allows you to adjust 
the pitch too, but only slightly.
Fine-tuning...
So to make small changes to the pitch,
to fine tune the Oscillator,
you use the Detune knob.
You following me ok?
Right. And that does it for the top part
of the Oscillator section.
Now, on to the Filter section.
The Filter is responsible for
processing the sound generated by
the Oscillator.
Ok? Let's start by looking here
at the Cutoff knob.
Let's move it and see what happens.
You can make the sound bright,
or dull...
Regardless of the Oscillator setting,
which at the moment is Sawtooth,
we can change the brightness of the sound.
What's going on here, though?
This is VERY important to understand!
What the filter does here,
is just like a coffee filter, really, 
it lets only certain things pass through.
Thus the name, Filter.
But what is being filtered?
The harmonics, that's what.
This is important!
The higher harmonics,
or you could say the higher frequencies,
are getting cut off. That's why this knob
I'm moving now is named Cutoff.
By cutting off the higher harmonics,
really, the higher frequencies,
progressively from high to low...
...the duller the sound.
The more harmonics present,
the brighter or sharper the sound.
Cutoff cuts those harmonics off.
There are a few different ways
we can go about cutting or shaping the sound.
This is also an important point.
Here in the Filter section,
there's a 'Mode' button, see it?
Right now LPF is lit up in red.
That stands for Low Pass Filter.
A Low Pass Filter allows only
low frequencies to pass through.
It cuts off the higher frequencies only,
without doing anything to the low frequencies.
It only cuts the high frequencies.
The lows are passed through as is.
That's why it's called a Low Pass Filter.
Next, we have the High Pass Filter.
Well, what do you know?
It works in reverse of the LPF,
cutting off the lows...
while allowing the highs to pass through.
How cool is that?
The High Pass Filter.
Next up, BPS, oops, BPF, sorry.
The Band Pass Filter...
CONTINUED...
