The Doppler

Knob-For-Knob Functionality

At Artium Instruments, we are committed to knob-for-knob functionality in our desktop synths. Every feature of the Doppler is directly mapped to a knob, button, switch, or jack, ensuring intuitive control. There's no need for menu-diving or complicated button presses to access features—everything is conveniently accessible at your fingertips.

Curated, Onboard Effects

With over a decade of experience in the effects industry, we have carefully curated a selection of effects that perfectly complement the synth core. Unique to the Artium Instruments desktop synths is its ability to use the onboard effects with other equipment, allowing you to route external audio through the input jacks on the back.

Plug and Play Functionality

The Swarm utilizes a USB-C MIDI host for simplicity and ease of use. Most modern class-compliant MIDI controllers with USB functionality should plug in and work immediately with zero setup. Additionally, The Swarm provides power to your controller, streamlining your setup process. For older controllers that only have DIN connections, a USB to DIN converter can be used to ensure compatibility. (These converters typically cost $10-20)

Intentional Design

We’ve invested considerable thought into crafting the overall feel of the instrument. From the layout of the knobs to the choice of colors, artwork, and the weight of the enclosure, every detail has been carefully considered. These details matter to us because we recognize that the connection a user forms with a piece of gear is nearly as crucial to the creative process as the sounds it produces. We hope you can feel the love and passion we've poured into every aspect of the Doppler—from its sonic capabilities to its design aesthetics.

Open Source Platform

Artium desktop synths use an open source platform known as Axoloti or Ksoloti for development and implementation of its products.  Click here for details on the open source platform being used.

2-Operator FM Synthesis

The Doppler is a polyphonic, 2-operator FM synthesizer with a unique approach to sculpting, tweakability, and has 8-note polyphony. It's designed for sonic exploration, where every knob twist reveals a new sound that's uniquely your own.

Ultra-Tweakable

Ultra-tweakability is at the core of the Doppler. It features a single, powerful algorithm, but the magic happens when you start adjusting its parameters. Even the subtlest tweaks lead to big shifts in the overall sound, making every turn feel like a discovery.

At the heart of the Doppler are two sine waves that form the foundation of its sound. The modulator wave is quantized and can modulate both the carrier's phase and frequency—or both at once for even more complexity. The carrier wave can even be sent through a feedback loop to modulate itself. Plus, there's a 9-octave pink noise source to modulate the carrier, adding texture and a lo-fi grit.

Quantized Modulator

The modulator sine wave features two rotary switches that control its frequency through a quantized octave and semitone shift. The Octave rotary switch offers a 5 octave range, allowing you to go two octaves above and two octaves below the carrier’s frequency. The Semitone rotary switch gives you a 12-semitone range, from the base note up to 11 semitones above. Both switches click into place and are perfectly quantized in relation to the carrier's frequency. 

Advanaced Envelope

The Doppler features a standard ADSR envelope, but there are a couple of cool nuances that really enhance its functionality. By default, the ADSR envelope only affects the carrier wave. However, when you flip the Env Mod toggle on, the envelope also influences the amount of frequency modulation applied to the carrier. On top of that, the Mod Trail knob lengthens the attack value, but only on the modulator wave. This gives you the ability to make the modulation swell in, adding an extra layer of depth.

Algorithm Diagram

All onboard effects can be used with other music equipment. Simply plug an external audio source into the rear input jacks, and The Doppler will seamlessly mix the external audio with its synth core, allowing for simultaneous processing of both signals.

Tap Tempo Delay

The Doppler delay is a tap-tempo digital delay with just a subtle touch of warmth. The delay length syncs with an internal clock, which you can set by tapping the red piezoelectric touchpad.

Reverb

The reverb in the Doppler is crafted to enhance the natural body and ambiance of the synth without overwhelming it. It's the same rich, organic reverb found in The Swarm, now with expanded control over both the level and feedback. This stereo reverb lets you move seamlessly from subtle room or hall effects to expansive, cathedral-like soundscapes, opening up a world of atmospheric possibilities.

SYNTH CORE

Octave - Sets the modulator's frequency by shifting its octave
Semitone -Sets the modulator's frequency by shifting its semitone
Phase FB - Sets the amount of phase feedback on the carrier wave
XMod - Sets the amount of modulation on the carrier wave
Noise - Controls the amount of frequency modulation caused by the pink noise source
Xfade - Crossfade between the carrier and modulator
Filter - Sets the cutoff frequency for the 4 Pole Low Pass filter
Phase Toggle - Turns phase modulation on and off
Freq Toggle - Turns frequency modulation on and off

ENVELEOPE

Attack - Sets the attack phase of the envelope
Decay - Sets the decay phase of the envelope
Sustain - Sets the sustain phase of the envelope
Release - Sets the release phase of the envelope
Env Mod - Turning this on makes the XMOD follow the ADSR envelope
Mod Trail - Lengthens the XMOD's attack value for a swell effect.

EFFECTS

Delay Level - Delay signal level
Delay FB - Number of delay repeats
Red Touchpad - Sets the tempo of the delay
Verb Level - Sets the amount of reverb
Verb FB - Length of reverb decay

REAR PANEL

Out(L) - Left Output (stereo headphone jack/TRS when Out(R) is unconnected)
Out(R) - Right Output
In(L) - Audio input to send external audio through onboard effects (If source is Mono, use In(L))
In(R) - Audio input to send external audio through onboard
Oct+:  Shifts the entire synth up one octave for every press
Oct-:  Shifts the entire synth down one octave for every press
MIDI HOST INPUT - Provides power and communication with your USB Midi Controller
USB POWER SUPPLY - USB-C plug to power synth

SETUP

With the included cables, connect the USB-C coming from the power supply brick to the "USB POWER SUPPLY" port on the back.  Within a few seconds, you will see the LED turn on and start to blink.  Plug any USB Midi Controller into the "MIDI HOST INPUT" on the back.  If necessary, use the included USB-C adapter.  Most Midi Controllers can be powered by this port and do not need external supply.  Most Midi Controllers need zero setup and will work immediately after plugging it in. Most issues can be resolved by unplugging and plugging back in.

ROTARY SWITCHES

With the Octave and Semitone rotary switches set to 12 o'clock, there will be no frequency shift, and the modulator's frequency will match the carrier's frequency. Turning the Semitone switch clockwise from 12 o'clock will incrementally shift the modulator's frequency up by one semitone at a time. The Octave switch has a 5-octave range, with two lower octaves to the left of 12 o'clock and two higher octaves to the right of 12 o'clock.

ENVELOPE

With the Env Mod toggle down, the ADSR envelope only affects the carrier wave. However, when you flip the Env Mod toggle on, the envelope also influences the amount of frequency modulation applied to the carrier. On top of that, the Mod Trail knob lengthens the attack value, but only on the modulator wave. This gives you the ability to make the modulation swell in, adding an extra layer of depth.

OCTAVE SWITCHES

The Doppler has two pushbutton switches on the back to offset the notes up and down by octave.  The LED will flash for 1 second when it is back to the original octave with zero offset.

OUTPUTS

The Doppler has stereo outputs.  You can use 2 mono (TS) cables and plug in to the Out(L) and Out(R).  You can also use a stereo (TRS) cable or headphone plug and insert it into the Out(L) as long as you don't have anything plugged into Out(R). 

INPUTS

You can route external audio through the Swarm.  The external audio is mixed in with The Swarm's synth core and both go through the effects.  If you have a mono signal, connect to In(L) and it will route to both sides. If you have a stereo signal attach to both In(L) and In(R) with mono cables (please note that the delay in the Swarm is technically mono, but will output to both outputs).