ACO160EVK
Audio‐to‐Synth Evaluation System
1
999 SW 1
st
Ave. #1617, Miami, FL 33130
ACO160EVK Audio‐to‐Synth System
Direct audio pitch to DCO
square/sawtooth/sine oscillator output
Low‐latency MIDI out with included
STM32F100C4 uC
1V/octave pitch CV output
Zero‐ripple envelope follower with
eight rate settings
Modulation CV input with +/‐2 octave
range in semitone resolution
Gate output with user‐configurable
threshold
25Hz‐5.2kHz frequency tracking range
Hard sync square wave oscillator from
10Hz‐10kHz generated by uC
Applications
Real‐time pitch‐to‐MIDI using virtually
any monophonic audio source
Audio‐controlled synthesizers
Pitch‐to‐CV converters
Pitch‐dependent audio processing
Harmonizers
Guitar and other instrument
effects/stompboxes
Description
The ACO160EVK Audio‐to‐Synth system is an
evaluation system for the ACO160 audio‐
controlled oscillator, an ultra‐low latency, low‐
power frequency‐tracking oscillator suitable for
audio‐controlled music synthesizer applications.
The ACO160 contains a fundamental frequency
detector based on dual switched‐capacitor peak
detectors with frequency‐dependent decay
time for ultra‐wide detection range, ultrasonic
analog oscillator and frequency tracking engine
that forces the analog oscillator to run at 8192
times the frequency of the incoming audio
signal detected at the input. This ultrasonic
analog oscillator is then divided back down to
audio range using programmable dividers that
are controlled by the harmony CV input and
which cover a +/‐2 octave range with semitone
precision over the entire range.
Additionally, the ACO160 features an integrated
switched‐capacitor envelope follower which
exhibits zero ripple, even for the lowest
frequency signals the chip can detect (down to
25Hz). An integrated gate generation
comparator has the envelope signal wired to its
positive input and allows the user to set the
voltage on the negative input. This voltage
functions as the gate threshold and generates a
rail‐to‐rail gate CV output.
The ACO160EVK additionally includes a
balanced preamp with combo XLR + ¼” jack
input with 0‐50dB gain, adjustable high‐pass
and low‐pass filters for improved frequency
detection (if needed) in front of the ACO160
chip, a VCA controlled either by the built‐in
envelope follower or by an external source, an
auxiliary mixer to mix another synth voice after
the VCA, and a STM32F100C4 micro‐controller
to convert the frequency, envelope and gate
information provided by the ACO160 chip into
MIDI commands to control digital synthesizers.
The ACO160EVK is meant to assist analog or
digital synth manufacturers with designing
products using its unique ACO technology and is
not intended to serve as a finished consumer
product.
Ordering Information
Part Number
Package
Size
ACO160EVK
PCB
140mm x 120mm
