Synthesizers.com Q170 MIDI Gates User manual

Q170 MIDI Gates
Aug 23, 2018
The Q170 MIDI Gates module produces gate signals from a stream of MIDI
messages, either from a keyboard, a DAW or any MIDI source. Each of the 8
outputs can be programmed for one or more MIDI note messages or Continu-
ous Controller messages.
Gate outputs can be used to select steps on a Q960 sequencer, trigger enve-
lopes, change filter settings and many other things.
A MIDI Thru output allows daisy-chaining of many modules.
The MIDI output is a version of the incoming MIDI signals but with the pro-
grammed notes filtered out. This allows you to set aside certain notes on a key-
board for controlling things via an independent gate signal.
To program an output, simply press the Set button and send MIDI note or CC
messages. MIDI channel numbers are recognized. Notes sent once cause the
output to follow the note on/off messages and operate like a simple keyboard
gate signal. Notes sent twice cause the output to toggle On then Off as note On
messages are received.
A special mode allows gate outputs to be programmed to respond to MIDI real-
time messages, sometimes called sync - start, stop, continue, clock. The clock
output can be programmed with a division
of /1, /2, /3, /4, /6, /8, /12, /16, /24, /32, /48, /96, /192.
Programming is preserved through power cycling.
Q170 MIDI Gates Specifications
Panel Size: Single Width 2.125"w x 8.75" (Moog Unit Format).
Gate Outputs: 5V positive.
Trigger Width: 5ms.
Power Requirement: +15V@30ma, -15V@30ma, +5V@50ma. Synthesizers.com standard.
MIDI Messages Recognized: Notes, Continuous Controllers, Clock, Start, Stop, Continue.
Clock Division Options: /1,/2,/3,/4,/6,/8,/12,/16,/24,/32, /48, /96, /192.
Total Messages Programmable: 100 per gate, 800 total.

MIDI input from a
keyboard, controller
or DAW.
The MIDI output has all
programmed notes
filtered out.
Outputs are 5 volt gate
signals that can be used
to trigger envelopes, set
sequencer stages, turn on
LFOs, adjust filter
responses, route signals,
transpose, and more.
Q170 MIDI Gates
LEDs show status
for each output.
For a toggle response, send
a MIDI note message twice.
Then the output will toggle
on/off each time that note is
received. Sending the note
three times produces a
short trigger pulse output.
To program an output,
press Set, send MIDI note
or CC messages,
then release. Each note
sent will be programmed
to activate the output.
Panel Overview
Clearing
Each time you press Set,
that output is cleared of all
previous programming.
Use the Thru output to send
MIDI to the next module.
The Q170 MIDI Gates module creates gate signals for specific keys of a MIDI keyboard or MIDI signal
source. Each of the 8 outputs can be programmed for any key or CC. Gates can be used to select steps
on a Q960 sequencer, trigger envelopes, change filter settings and many other things. A MIDI Thru out-
put allows daisy-chaining of many modules and a MIDI output has the programmed notes filtered out.

Q170 MIDI Gates
MIDI Message Interpretation
In these examples, a keyboard is assumed to be the source of MIDI messages to the Q170 MIDI Gates
module. The source could be any other controller or a computer (DAW). Every message, without excep-
tion, is sent to the MIDI Thru output. MIDI messages are also sent to the MIDI output but with the pro-
grammed messages filtered out.
Note On/Off Messages
Programming gates to follow MIDI Note messages is the primary function of the Q170. Any note number
can be assigned to any Gate output, and many notes can be assigned to each Gate output.
There are three different modes for responding to Note On/Off messages.
Follow Mode
In Follow mode, programmed Gate outputs simply follow note messages. A Gate output will turn On
when a Note On message is received and turn Off when a Note Off message is received. Activate Follow
mode by simply pressing and releasing a key while the Set button is pressed.
Toggle Mode
In toggle mode, the programmed Gate outputs toggle between On and Off as Note On messages are re-
ceived. The first Note On will turn the Gate output On, then the second will turn it Off. Note Off mes-
sages are ignored. This mode is useful for turning effects or settings On and Off without requiring a key
being pressed. Activate Toggle mode by pressing and releasing the key twice while the Set button is
pressed.
Trigger Mode
In Trigger mode, the programmed Gate outputs turn on for a short duration (5ms) then turn Off. You'll
see the LED flash briefly. Note Off messages are ignored. This mode is useful for triggering sequencers
or AR envelopes. Activate Trigger mode by pressing and releasing the key three times while the Set but-
ton is pressed.
When multiple notes are programmed to a single Gate output, the last message received will override
others that are currently active. One key can toggle a note On and another can turn it Off.
Continuous Controller (CC) Messages
Gates can be programmed to CC messages. These are programmed the same way as Note messages -
press the Set button for the desired Gate output, send the message, then release the Set button.
There are 128 possible CC's. Some are typically assigned to volume, modulation and other common
functions so select thoughtfully. Each CC message contains a value of 0-127.
CC messages from a slider or knob transmit a stream of messages as the controller is moved. CC mes-
sages from a button just send a single message. If the Q170 receives more than one CC message from
a CC number while Set is being pressed, it will be programmed as a knob or slider and the value of the
controller determines the Gate output. Values of 0-63 are Off and 64-127 are On.
If the Q170 receives only one CC message from a CC number while Set is pressed, it will be programmed
as a button and the Gate output will Toggle between On/Off as the button is pressed.
If an output is programmed as a button (toggle on/off behavior) and messages for a knob/slider of the
same CC # are sent, the output will toggle on/off very fast as the knob/slider is moved. This is the correct
behavior and potentially musically useful.

Q170 MIDI Gates
MIDI Message Interpretation
Other MIDI Messages
The following MIDI messages are not programmable and are passed through to the Thru and Output con-
nectors - aftertouch, program change, channel pressure, pitch wheel, system common messages. There
is no compelling reason to add the complexity and processing time required for programming these mes-
sages since note and CC messages provide an abundant source.
System Real Time Messages
System Active Sensing messages are ignored and not passed to the MIDI output.
System Reset clears all outputs and resets internal clock dividing counters.
System real time messages Clock, Start, Continue and Stop can be programmed by pressing specific Set
buttons multiple times without sending MIDI data. When one of these messages is programmed to a
Gate output, no note or CC message can be programmed to that output.
Press Set #1 twice without sending MIDI data to program it for MIDI Start. When a MIDI Start message is
received, output #1 will produce a short trigger pulse. This can be used to start analog sequencers.
Press Set #2 twice without sending MIDI data to program it for MIDI Continue. When a MIDI Continue
message is received, output #2 will produce a short trigger pulse.
Press Set #3 twice without sending MIDI data to program it for MIDI Stop. When a MIDI Stop message is
received, output #3 will produce a short trigger pulse.
Outputs 4-8 can be programmed to respond to MIDI clock with a division of your choice. Press the Set
button multiple times without sending MIDI data to program that output for clock with a certain division.
Press Set Division Press Set Division
2 times /1 9 times /16
3 times /2 10 times /24
4 times /3 11 times /32
5 times /4 12 times /48
6 times /6 13 times /96
7 times /8 14 times /192
8 times /12
Programmed System messages are removed from the filtered MIDI output as expected.
Every message, without exception, is sent to the MIDI Thru output.
Factory Defaults
Press Set #1 during power-up to reset the Q170 and clear all programming.

Basic Usage
Here's a basic patch with a keyboard producing MIDI messages. The Q170 MIDI Gates module creates
gates according to its programming and the MIDI signal is sent on to the Q174 MIDI interface module to
produce pitch and gate for a synth voice. The gates from the Q170 can be used to start sequencers, trig-
ger additional envelope generators, or
provide voltages to adjust parameters
in filters and other modules.
The Level control on the filter
allows the 5 volt gate signal
to control the filter frequency.
This example shows a gate output controlling a filter setting.
Q170 MIDI Gates
Q174
MIDI Interface
MIDI Gate
Pitch
QKB37 Keyboard Controller
Q170
MIDI Gates
MIDI
Gate
Outputs
Q170
MIDI Gates Q107 Filter

Keyboard
Pitch
Output
Sequencer Step Selection Patch
This patch lets the user select specific steps on a Q960 sequencer. Program the Q170 MIDI Gate mod-
ule to respond to an array of keys, then set the sequencer knobs to voltages that correspond to any note
you wish. This allows a keyboard to produce arbitrary notes, or allows programmed keys to select a set
of control voltages to adjust a patch at will. Patch the Thru output to a Q174 to produce a combined gate.
Q170 MIDI Gates
Q170 Q174
Combined
Voice
Gate

Transposing
This example uses a gate output to transpose specific notes. The 5V gate signal is patched into the
Q106 VCO's variable 1V/Octave CV jack. Adjust the knob for the transposition you want. With this patch,
certain keys on a keyboard could be transposed, possibly an octave higher or some other musically use-
ful amount.
This example turns vibrato on and off for specific keys on a keyboard, or under control of a CC. The gate
from the Q170 controls the LFO's built-in amplifier which adds vibrato to an oscillator being used in a nor-
mal synth voice patch. Program the gate for the keys you want to have vibrato.
Audio
to the rest
of the
patch
Q170 MIDI Gates
The Amount control sets the
amount of transposing.
Q170
MIDI Gates Q106 Oscillator
Q106 Oscillator
Q170
MIDI Gates Q167 LFO
Pitch CV
From Q174
MIDI Interface
Vibrato Control

Press Set #1 twice without
sending any MIDI data and
it will be programmed to
respond to the MIDI Start
message.
DAW
Pitch
Output
Sequencer Clock Control
In this patch, gate outputs from the Q170 are used to clock a Q960 sequencer and to restart it for syncing
to other gear or a DAW. Patch MIDI Thru on to the Q174 MIDI Interface for normal pitch/gate creation.
The unused gate outputs can be used for other things if you want.
Q170 MIDI Gates
Q170
Press Set #4 twice without
sending any MIDI data and
it will be programmed to
respond to the MIDI Clock
message.

Troubleshooting
Remove the AC cable from the system before opening a system.
Never install or remove the power connector on a module with power on.
If no operation, check the power connection, possibly trying another one. Also inspect the circuit board
for loose cables.
Perform a reset to factory defaults by pressing Set button #1 during power-up.
There are no jumpers on the Q170.
After releasing a Set button, the programmed data is saved internally and this takes a second or two. Be
slow and methodical when programming.
There is a delay between the time MIDI data is received at the input and MIDI data is sent at the filtered
output since an entire message must be analyzed before resending. Under normal playing conditions this
delay is unnoticeable. MIDI thru has no delay and is a direct copy of the MIDI Input.
To clear a channel, simply press its Set button once without sending any MIDI data.
Remember that pressing a Set button more than once without sending data programs special features
which can cause confusing behavior. MIDI Clock is one example.
Remember that sending a note button more than once while the Set button is pressed activates the Tog-
gle on/off and short triggering options.
The gate outputs should not be patched to other outputs in the system, only inputs.
Sometimes continuous controller knobs and sliders send data without being moved because they are
dirty or are sitting on a threshold. If this happens, programming will be erratic because while the Set but-
ton is pressed, undesired CC messages are being sent and programmed. When the Set button is re-
leased, the gate output will fire as the undesired CC messages continue. Often, turning the knobs or
moving the sliders will solve this, especially on older gear.
Q170 MIDI Gates
The time between MIDI input data and Thru output data is ~0s since it's a hardware connection.
The time between the start of MIDI input data and the start of filtered data output is 0.65ms. That in-
creases to 0.75ms if there are 10 notes programmed for each of the 8 channels. This is due to the soft-
ware having to read the entire MIDI message before resending to the filtered output, and the search for
programmed notes.
The time between the start of MIDI clock data and the start of a rising clock edge is between 0.4ms and
1.4ms.
MIDI Time Delays