This is the 2nd article in which we'll take a good look at a particular instrument, the PCMSynth, in...

1. Caustic for Android - Getting to Know the PCMSynth
This is the 2nd article in which we'll take a good look at a particular instrument, the PCMSynth, in
the Android Digital Audio Workstation (DAW), Caustic.
PCM stands for Pulse-Code Modulation. Â PCM is the standard form of digital audio found on CDs,
digital phones, and portable music devices.
There are two properties always found in a stream of a PCM signal: Â sampling rate, and bit depth.
 Sampling rate is how many times per second the recording device (sampler) takes a 'sample' of the
original sound. Â Bit depth is how detailed or coarse the sample may be, determined by the
maximum number of sampling points.
Caustic's PCMSYNTH loads samples of sounds, and allows you to apply filters, LFO's, volume
ADSR's, pitch control, and also provides some on-board sample editing features.
Features Found in the PCMSynth
I'm going to assume that you know how to start up Caustic, and get to the PCMSYNTH screen. Â If
not, take a look at my article on the Subsynth, which shows you how to navigate the screens in
Caustic.
Let's go over each section of the PCMSYNTH, section by section. Â I'll cover the sections by going
from left to right, starting at the top, and working my way down.
1st SECTION - PRESETS:
MACHINE NAME
It's called PCMSYNTH by default, but you can rename it by long-pressing it
NOTE ON
Let's you know visually if the PCMSYNTH is generating any sound
PRESETÂ name
Touch this field to load a PCMSYNTH preset
DISKÂ icon
Saves any changes to the currently loaded preset
2nd SECTION - FILTER:
CUTOFFÂ slider

2. Use to select the frequency at which the current filter takes effect
RES slider
Use to select the amount of resonance applied to the current filter
ATTACKÂ dial
Controls how much time passes between the key press, and reaching the amount set by the
cutoff slider
DECAYÂ dial
Time taken after attack for the cutoff value to reach the sustain level
SUSTAINÂ dial
After attack & delay have happened, this is the level that the cutoff settles at, as long as the key
remains pressed
RELEASEÂ dial
Time for cutoff to go from the sustain level to fully off, or, zero
3rd SECTION - LFO1:
(LFO: Low Frequency Oscillation)
 LFO name
Currently selected LFO. Â There are 8 types available for use
LFO 1 Waveform
4 Waveforms are available for use in shaping how the LFO1 operates
Sine
Triangle
Sawtooth

3. Square
RATEÂ dial
Controls LFO1's speed, as applied to the original sound
DEPTHÂ dial
Controls LFO1's amount, as applied to the original sound
4th SECTION - PITCH:
OCTAVEÂ dial
Tunes the signal by octaves, up or down the keys
SEMIÂ dial
Tunes the signal by semitones
CENTSÂ dial
Tunes the signal by cents
5th SECTION - SAMPLE CONTROL
This section contains a display window, a large dial, and a number of buttons. Â The large dial is
used to cycle through various things shown on the display, depending on which button is pressed in
the section.
The available buttons are:
SAMPLE
Shows what sample(s) are loaded for
the selected preset. Â More than one
sample can belong to a preset
Long-press to load a sample
LEVEL
Volume level of the sample. Â Use the large dial to change the value
Long-press to bring up the editor
TUNE
Use the large dial to change the value by cents

4. Long-press to change to PAN control
ROOT KEY
Sets the root key on the key board for the sound. Â Typically, this key is the same pitch as the
sample, but not always.
Long-press to select a key by using the keyboard keys
LOW KEY
Sets the lowest key that will play the sample
Long-press to select a key by using the keyboard keys
HIGH KEY
Sets the highest key that will play the sample
Long-press to select a key by using the keyboard keys
MODE
Sets the playback mode for the selected sample. Â Options are:
Play once
Note On/Off
Loop Forward
Loop Forward-Backward
Intro + Loop Forward
Intro + Loop Forward Backward
START
Point in time (of the sample itself) to begin playback after a key is pressed
END
Point in time (of the sample itself) to end playback after a key is pressed
6th SECTION - VOLUME ENVELOPE:
ATTACKÂ dial
How long it takes after key press for the volume to reach maximum level

5. DECAYÂ dial
How long it takes after attack for the volume to drop to the sustain level
SUSTAINÂ dial
Sets the volume to hold the note at, after attack and sustain, provided the note is still held
RELEASEÂ dial
How long it takes for the volume to go from the sustain level to off
7th SECTION - VOLUME OUT:
VOLUMEÂ dial
Final output volume of the PCMSYNTH sound
VOLUME LEVEL METER
Shows you graphically the level of the sound output. Â Your outputting distortion if your meter is in
the red (which isn't always bad, if that's the sound you are looking for, pre-effects)
8th SECTION - KEYBOARD & POLYPHONY:
M & S Buttons
MUTE (turns off all sound from this PCMSYNTH, even during playback)
SOLO (turns off all other sounds except this PCMSYNTH, even during playback)
"- or +" POLYPHONY
Let's you decide how many notes can simultaneously sound at any given time, up to 8Â
KEYBOARD
One of the places to initiate sound. Â Key size can be selected in the 'Options' menu
Keyboard UP/DOWN Arrows
Let's you determine at which octave on the keyboard to play
Keyboard Controller that Works With Caustic

6. Behringer U-Control
UMX250 25-Key USB/MIDI Controller Keyboard with USB/Audio Interface
Amazon Price: $169.99 $129.99 Buy Now
(price as of Oct 25, 2013)
Folks who use Caustic have reported satisfaction with this keyboard controller. Go on over to
Amazon & read the reviews, and see if it fits your needs. Behringer also make units with more keys
as well, so check them out.