Rare Waves Grendel Grenadier RA-99 User manual

CV-Gate Analog Music Synthesizer
Rare Waves LLC
RAREWAVES.NET
GRENADIER RA-99

Introduction
In the spirit of sonic exploration and musical evolution we bring you the Grendel RA-99 Grenadier, an all-
analog synthesizer with an original and unique tone palette. It implements parallel formant synthesis with a
bank of three voltage controlled filters to generate tones inspired by the human voice, without being
limited by the conventional boundaries of speech modeling. Twenty patch points give you extensive self-
patching options plus creative compatibility with analog modulars, sequencers and keyboard controllers.
Oscillator
The RA-99 sound engine is based on an accurate voltage controlled oscillator with variable wave shape.
The VCO has multiple CV (control voltage) inputs for creative stacking of the various CV sources available
in your studio. There are two 1 volt per octave inputs for melody. It also has a 5 volts per octave input
that is ideal for creating octave modulations from an LFO with 5V output. Finally, the 15 volts per octave
input is suited to narrow pitch modulations like vibrato and pitch bend. The CV inputs of the RA-99 VCO
have wide response bandwidth, allowing FM with audio frequency waveforms.
A subharmonic square wave is generated at a frequency 1 octave below the VCO. Activating the SUB
switch mixes this with the VCO output. Raw subharmonic waveform is available from the SUB OUT jack.
Noise Source
A pink noise generator is included to add complexity to the sound. Pink noise is mixed with the VCO at
the input to the filter bank. Pink noise volume is adjustable with the knob labeled P-NOISE, and by CV
input to the NOISE CV jack. The noise source also adds a subtle amount of jitter to the VCO waveform.
Modulation
The RA-99 modulation section contains a pair of multifunction waveform generators called MOD1 and
MOD2. They can provide (1) gated attack-release envelope, (2) triggered decay envelope, (3) pulse LFO
with variable pulse width, or (4) saw-triangle LFO with variable symmetry. In envelope mode, the output
is a true exponential slope. In addition, RA-99’s MODs can create time delayed gate events, serve as low-
frequency audio VCOs (with limitations), or act as frequency dividers. Both MODs have variable output
level that is sweepable from normal to inverted polarity. Either MOD1 or MOD2 can serve as the main
volume envelope.
Filter Bank
The Grenadier RA-99 filter bank combines one low pass and two band pass filters to produce full-bodied
tones with resonant character of vowels. The filter bank has three control parameters: ALPHA, BETA, and
FILTERS. These parameters are also fully controllable with CV inputs.
Patch Points
Made by Rare Waves® (Texas, USA)
RAREWAVES.NET
Design and Support:
Eric Archer
Manufacturer
Compatibility
CV-Gate In:
Patch cables:
Audio output:
CV output range:
MIDI:
Polyphony:
VCO
1V/oct (x 2), 5V/oct, 15V/oct,
Timbre CV In (controls wave shape)
MOD1
Gate In, Rate CV In, Vari Out, Gate Out
MOD2
Gate In, Rate CV In, Vari Out, Gate Out
Filter Bank
Alpha CV In, Beta CV In, Filter CV In
Audio
Subharmonic Out, VCF audio In,
Mix audio In, Noise VCA CV
Specification
Power Input:
Dimension:
Mass:
Case Material:
RoHS-Compliant:
Lead-free:
12 VDC @ 1.2 Watt
30 x 10 x 6 cm
0.53 kg
Anodized aluminum
YES
YES
1 V/oct, +5V Gate
3.5 mm mono
1/4” analog unbalanced
0 to +5 volts
Not included
Monophonic
Grendel RA-99 Grenadier User Guide | Revision 2020-0103

Power Input
This unit requires 12 volts DC and draws a maximum current of 100 mA.
Polarity of the AC adapter connector does not matter. It can be tip positive or tip negative.
* Grenadier RA-99 will also operate from 9 volts DC, but please note that the pink noise source will be unavailable in this situation, and
distortion may be heard in the output.
The unit is protected against over-voltage with a built-in self-resetting fuse.
It is OK to use a daisy-chain cable to share power with other 12V gear from
a single AC adapter, provided the total current demand (mA)
does not exceed the AC adapter’s rating.
Tip positive OK
Tip negative OK
12 VDC 100 mA
2.1 mm tip
Power Switch?
For simplicity, this unit does not have a
power switch. It is on whenever its AC
adapter is connected to mains power.
We suggest plugging its AC adapter to a
power strip with on-off switch built in.
This unit uses approximately 1.2 watts of power while in
operation. Assuming an energy cost of $0.13 per kWh, it
would cost about $1.35 per year to leave it on all the time.

Main Audio Output
Use a common 1/4” shielded audio instrument cable (mono, TS type) to connect the synth’s output to a line input
of a mixing board, computer sound interface, keyboard amplifier, or effect processor.
The output impedance is 220 ohms, so it is unnecessary to connect it to a high impedance (HI-Z) input.
You may plug headphones in to this jack, but you’ll only hear sound on one side.
DI Box may be necessary on stage to connect to a PA system.
For best sound quality, always connect the Grenadier to a grounded (earthed) audio system.
Normally the mixing board, amplifier, and/or powered monitor speakers have 3-prong AC
plugs. This provides grounding, which is important to maintain a clean noise oor in the
analog audio signal path.
If every device in an audio system is running from AC adapters with 2 prongs (or batteries)
then the system is electrically ‘oating’. It is likely that the noise oor will be contaminated
with humming, buzzing, and noise from the AC adapters.
Grounding
Grendel RA-99 Grenadier User Guide | Revision 2020-0103

Quick Start
Here are some suggestions for connecting the Grenadier RA-99 to other analog equipment in the music studio.
RA-99 uses the 1 volt per octave tuning standard (not V/Hz). Its Gate inputs interpret >2.5 volts as Gate On, and < 2.5 volts as Gate Off.
Nominal Gate input is 5 volts, but there is no harm in connecting a 10 volt gate input.
Connection to a sequencer
Connection to a keyboard controller
Connection to a computer
Connection to a modular
Patch the sequencer’s V/OCT output to RA-99’s 1V/OCT. Patch the sequencer’s GATE output to RA-99’s MOD1 GATE IN.
A sequencer’s ACCENT GATE output is not directly supported, but you can experiment by connecting it to ALPHA CV, BETA CV, TIMBRE CV,
or FILTER CV. Or, connect ACCENT GATE to MOD2 GATE IN. Then the second envelope generator will trigger just for accented notes.
If you have two analog sequencers, or a 2-track sequencer, try using both of RA-99’s 1V/OCT inputs simultaneously. This greatly expands the
musical possibilities. For example, one sequencer could play a fast octave arpeggio while the other transposes the root note.
Patch your analog key controller’s V/OCT output to RA-99’s 1V/OCT. Patch the keyboard’s GATE output to RA-99’s MOD1 GATE IN.
If the key controller has Velocity Out, you can experiment patching it to RATE CV, ALPHA, BETA, TIMBRE, FILTER, or NOISE CV.
You can also use any MIDI keyboard to play the Grenadier, but this requires a MIDI-to-CV converter. See Connection to a Computer below.
You can play the Grenadier RA-99 with DAW software on a computer. A MIDI-to-CV converter is required.
Remember, the Grenadier is a monophonic instrument, which means it only sounds one note at a time. It can’t play chords.
Patch the MIDI-to-CV’s V/OCT output to RA-99’s 1V/OCT. Patch the MIDI-to-CV’s GATE output to RA-99’s MOD1 GATE IN.
Experiment with patching any auxilliary outputs of the MIDI-to-CV converter (Velocity, Wheel, Bender) to the various CV inputs on the Grenadier.
If your MIDI-to-CV converter has multiple channels, try using both of Grenadier’s 1V/OCT inputs simultaneously to expand your compositions.
Grenadier RA-99 is generally compatible with Eurorack style equipment.
There are many options ... have fun. Remember, the more patch cables you use, the better it sounds!
*
Standalone operation
Grendel RA-99 Grenadier can be played manually for sound effects and drone tones without connecting a sequencer or keyboard.
You’ll need a handful of patch cables to get started.
Self-patching MOD GATE OUT to the other MOD GATE IN and using the LFO switches allows its envelope to re-trigger.
You can also patch SUB OUT to GATE IN to self-trigger the modulation generators.

Tuning Controls
V/OCT IN jacks
FINE TUNE has a range of +/- 7 semitones. In other words, if you start
with the knob centered, turning it all the way will transpose the pitch by
a perfect 5th interval.
OCTAVE has a range of +/- 5 octaves. This is a rotary potentiometer
(not a “clicks” switch).
Patch 1V/OCT to the V/OCT output from your sequencer, MIDI-CV converter, or analog keyboard controller
5V/OCT is less sensitive. A change of 5 volts tunes the oscillator by 1 octave. It works well for octave trills when you patch
it to an LFO with 5 volt square wave output. For example, patch MOD2 GATE OUT to 5V/OCT.
15V/OCT is the least sensitive CV input. A change of 15 volts would tune the oscillator by 1 octave. A change of 1.25 volts
equals 1 semitone. Therefore, if you connect a pitch bender with +/-2.5 volts output, you’ll have the standard +/- 2
semitone bend range. 15V/OCT is also useful for vibrato and other narrow pitch expressions.
Q. Any tips on tuning this instrument to match my sequenced
compositions?
A. If you are controlling it from a keyboard and a sequencer or DAW:
Begin by setting FINE TUNE to its center position. Play a reference note
on the key controller such as middle A. Adjust OCTAVE carefully until
the Grenadier is sounding the reference note approximately in tune.
Then use FINE TUNE to tweak and transpose the pitch.
Be careful not to turn OCTAVE by mistake during a performance.
Grendel RA-99 Grenadier User Guide | Revision 2020-0103

GATE IN jacks
Patch GATE IN to the GATE output of your sequencer, MIDI-CV converter, or analog keyboard controller
MOD2 GATE IN is normalled to MOD1 GATE IN.
In other words, MOD2 gets the same gate as MOD1 unless a patch cable is connected to MOD2 GATE IN.
It is OK to patch other types of signals to GATE IN. There is no harm in connecting it to an LFO, envelope, oscillator, etc.
Any waveform that crosses the 2.5 volt threshold will generate gate events.
VOLUME ENVELOPE switch
Either MOD1 or MOD2 can control the synthesizer’s main volume envelope.
Press the VOLUME ENVELOPE switch to alternate between the options.
There is no direct CV input for the volume envelope.
*

TIMBRE knob
The controls the VCO’s wave shape to alter its harmonic content.
The slope and pulse width vary simultaneously in a trapezoidal shape.
The effect on the waveform is illustrated in the diagram to the left.
TIMB. CV jack
Patching a CV input to this jack has the same effect as turning the TIMBRE knob.
Both the knob and the jack can be used simultaneously.
TIMB. CV responds well when controlled by an envelope or LFO, adding smooth
modulations to the VCO waveform’s harmonic content.
TIMBRE VCO waveform
Grendel RA-99 Grenadier User Guide | Revision 2020-0103

SUB switch
SUB OUT jack
Activating this switch blends subharmonic
square wave with the VCO waveform
The unfiltered subharmonic waveform is available from this jack.
It is a square wave with 5 volts amplitude.
You can self-patch this output to the RA-99’s other CV, Gate and audio inputs for many tone variations.

P-NOISE knob
Controls the volume of the pink noise source.
Noise is mixed with the VCO and subharmonic and fed to the filter bank.
NOISE CV jack
This input controls the volume of the pink noise source VCA.
It has the same effect as the P-NOISE knob.
Both the knob and the jack can be used together.
If the noise source does not seem to be working, make sure you are using a 12 volt DC power supply.
If you connect a power adapter with lower voltage such as 9 volts, the unit will appear to operate normally, but the noise source will not work.

VCF IN & MIX IN jacks
These are analog audio inputs to the filter bank.
Patching to VCF IN mutes the internal VCO, replacing it with external audio.
Patching to MIX IN blends external audio with the internal tone generator.
Both can be used simultaneously
VOLUME knob
Sets the audio level at the main output
Grendel RA-99 Grenadier User Guide | Revision 2020-0103

RATE knobs
These set the speed of the envelope and LFO. The control range is approximately 1000:1
The maximum LFO frequency is approximately 50 Hz, and minimum is approximately 0.05 Hz (about 3 cycles per minute).
The SHAPE knob also affects the rate. With SHAPE rotated to either extreme, the LFO runs about half as fast as when SHAPE is
centered. For slowest possible LFO, set SHAPE to either limit and turn RATE to minimum. The LFO rate will be about one cycle
per 50 seconds.
The LED indicators to the left of the RATE knobs ash in time with the LFO and indicate the phase of the envelope.
RATE CV jacks
These voltage control inputs set the speed of the envelope or LFO.
They have the same function as the RATE knobs and can be used simultaneously.
The response is approximately 1 volt per octave.

WAVE switches
LFO switches
When its LFO switch is Off, a MOD is an envelope generator controlled by its GATE IN jack.
When its LFO switch is On, a MOD is an LFO with sawtooth, triangle, and pulse waveforms.
These change the waveform that is applied to the DEPTH
knob and VARI OUT jacks.
When WAVE is Off, the output is smooth, gliding
When WAVE is On, the output is pulses, discontinous
The WAVE switches do not affect Volume Envelope
LFO SHAPEWAVE GATE IN
off - -off Gate In
off TRIGoff Trigger In
MOD function
Attack - Release envelope, exponential slope
Decay envelope, exponential slope
off - -ON Gate In
off TRIGON Trigger In
Pulse envelope (Gated)
Pulse envelope (Triggered)
ON - -off ignored
ON TRIGoff LFO Sync
Sawtooth - Triangle LFO, variable symmetry
Falling sawtooth LFO, retriggered by Gate In
ON - -
ON
ignored
ON TRIGON LFO Sync
Pulse LFO, variable symmetry
Narrow pulse LFO, retriggered by Gate In
Grendel RA-99 Grenadier User Guide | Revision 2020-0103

SHAPE knobs
In envelope mode, SHAPE varies the attack-release times of the envelope generator. Turn SHAPE
to the TRIG position and it becomes a decay envelope triggered by GATE IN.
In LFO mode, SHAPE varies the symmetry of the LFO output.
Turn SHAPE to the TRIG position and it becomes a falling sawtooth LFO that is re-triggered
(synced) by GATE IN events.
These parameters do not have voltage control CV inputs.
GATE OUT jacks
In LFO mode, GATE OUT is a pulse wave with fixed amplitude of 5 volts.
In envelope mode, the output is an inverted gate. When the GATE IN is inactive, and the
envelope is settled, the output is high (+5V). When you trigger the GATE IN, GATE OUT
goes low (0V) until the envelope expires, then goes high again.
Therefore you can use GATE OUT as a variable gate delay. For example, if you patch
MOD 1 GATE OUT to MOD 2 GATE IN, it works as a 2-stage envelope generator.
GATE IN
Decay
Envelope
GATE OUT
Gate Delay example with Gate Out
Time delay factor is adjustable with RATE knob.
Frequency divider example with LFO in TRIG mode.
If the LFO is retriggered before it completes 1/3 of a
cycle, the output is a stair-step waveform at a frequency
equal to the input divided by a whole number.
... That is to say, triggering the LFO rapidly can do
interesting and useful things!
GATE IN
LFO
Waveform

DEPTH knobs
These are bipolar attenuators for the MOD outputs.
To cancel the modulation, set the DEPTH knob straight up (12 o’clock).
By default, MOD1 DEPTH controls the ALPHA parameter, and MOD2 DEPTH controls BETA.
You can change this assignment with the patch bay.
These parameters do not have voltage control CV inputs.
VARI OUT jacks
These are the outputs from MOD1 and MOD2, after attenuation by the DEPTH knobs.
The output voltage range is 0 to +5 volts.
When DEPTH is set at minimum (straight up, 12 o’clock), VARI OUT is steady at 2.5 volts.
MOD1 VARI OUT is internally connected to ALPHA CV.
MOD2 VARI OUT is internally connected to BETA CV. See the following page for options...
Grendel RA-99 Grenadier User Guide | Revision 2020-0103

ALPHA and BETA knobs
These control the filter bank and can morph between vowel tones when you find a sweet spot.
ALPHA CV and BETA CV jacks
These affect the filter bank in the same manner as the ALPHA and BETA knobs, and can be used simultaneously.
Remember:
By default, MOD 1 VARI OUT is internally connected to ALPHA CV. Plugging a patch cable in to ALPHA CV breaks this connection.
By default, MOD 2 VARI OUT is internally connected to BETA CV. Plugging a patch cable in to BETA CV breaks this connection.
To stop MOD DEPTH from modulating the filters so you can use VARI OUT for other purposes, dead patch ALPHA CV or BETA CV.
To dead patch, just plug in a patch cord to ALPHA CV or BETA CV and leave its other end unconnected.
*

FILTERS knob
This is an important filter bank parameter that has the general effect of tuning it from from low to high.
It can also inuence the vowel tones, depending on the settings of Alpha and Beta.
Please note, the RA-99 filter bank is not designed for full cutoff, as in a conventional low pass filter.
FILTER CV jack
This has the same effect as the FILTERS knob, providing the option of voltage control.
Both the knob and the jack can be used simultaneously.
The resonance (Q factor) of the filter bank is not adjustable.
The filter bank can not be bypassed.
Grendel RA-99 Grenadier User Guide | Revision 2020-0103

VCO trimmer
This is used to calibrate the V/OCT inputs for accurate pitch scaling. It affects all of the V/OCT inputs.
For a quick tuning check, patch MOD 2 GATE OUT to 5V/OCT. Set MOD2’s LFO switch ON. The
VCO should be playing a sequence of alternating octaves.
This is used to calibrate the Volume Envelope VCA to match the envelope generators.
When it is set properly, decaying notes fade away to silence with accurate exponential character.
If it is not set correctly, notes may continue to sound after the envelope decays fully.
If it is not set correctly, the tails of decaying notes may be clipped off prematurely.
** Note that there are two envelope generators, and their RATE knobs have a slight inuence on the envelope
baseline (quiescent) voltage level. So its best not to obsess over setting this trimmer perfectly. Just make sure the
decay envelope fades completely to silence at any combination of settings on VOLUME ENVELOPE and RATE.
VCA trimmer
Q: What type of tool do I use to adjust the
trimmers?
A: Use a screwdriver with at blade or
Philips tip, 2.5 mm, 3.0mm or 1/8”

Creative self-patching will let you uncover many tone variations in the Grenadier RA-99. This page presents a few ideas as starting points.
** These patches don’t show CV-Gate input from your controller or sequencer, which are usually connected to 1V/OCT and MOD1 GATE IN.
Octave Trills
MOD2 LFO = ON
2-Stage Envelope
MOD1 LFO = off
MOD2 LFO = off
Pure Square Wave Drone Mode
Volume Envelope = MOD1
MOD1 LFO = off
Bass Drop
MOD2 LFO = off
MOD2 SHAPE = TRIG
MOD2 WAVE = off
MOD2 DEPTH = full CW
Vibrato
MOD2 LFO = ON
MOD2 SHAPE = center
MOD2 WAVE = off
Waveform Variation Subharmonic Divider
MOD2 LFO = ON
MOD2 SHAPE = TRIG
MOD2 DEPTH = full CW
Grendel RA-99 Grenadier User Guide | Revision 2020-0103

Creative self-patching will let you uncover many tone variations in the Grenadier RA-99. This page presents a few ideas as starting points.
** These patches don’t show CV-Gate input from your controller or sequencer, which are usually connected to 1V/OCT and MOD1 GATE IN.
Dead Patch Alpha
MOD1 is disconnected
from filter bank
X
Dead Patch Beta
MOD2 is disconnected
from filter bank
Die Twice
MOD1 and MOD2 are both
disconnected from filters
X
Auto Drum
MOD1: LFO ON
MOD2: LFO OFF, Shape = TRIG, DEPTH = +5
Breathing
MOD1: LFO ON, WAVE ON, SHAPE = center,
RATE = 0.2, DEPTH = -1
MOD2: LFO OFF, WAVE OFF, DEPTH = +3
P-NOISE = 4
X
FM Drone
MOD1: LFO ON, RATE = 30..50
MOD2: LFO ON, RATE = 30..50
Grendel RA-99 Grenadier User Guide | Revision 2020-0103