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Drambo

Chapter 10

Build a synth

From one buzzing oscillator to a polyphonic two-oscillator synth saved as a preset, then pitch, glide and MPE.

Written in our own words from the Drambo docs’ first synth and recipes pages. Read the Drambo docs

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In this chapter · 11
  1. 10.1Start with an oscillator and an envelope
  2. 10.2Insert a filter
  3. 10.3Give the filter an envelope
  4. 10.4Add a second oscillator and a mixer
  5. 10.5Polyphony and drive
  6. 10.6Wrap it in an Instrument rack and save it
  7. 10.7How pitch works
  8. 10.8Key tracking
  9. 10.9Glide and portamento
  10. 10.10Ring modulation, sync and unison
  11. 10.11MPE
10.1Basics

Start with an oscillator and an envelope

This chapter builds a small subtractive synth step by step — two oscillators, a filter with its own envelope, an amp envelope, polyphony and some drive — then packs it into an Instrument rack and saves it as a preset. Each step shows a bit more of how the modular side thinks.

  1. Tap track pad 1 to make the first track current.
  2. Tap +. The library browser opens.
  3. Choose Oscillator from GENERATOR / OSCILLATOR. The track now has a constant buzz.
  4. Tap + again and choose Amp env ADSR from PROCESSOR / AMP. Now the sound starts and stops with the notes you play.

Look at what’s in the rack. The coloured column at its left edge belongs to the track itself: its output and settings. Next comes MIDI to CV, which turns the track’s MIDI notes into pitch, gate and velocity signals. The oscillator’s pitch input is the same green as MIDI to CV, so that’s where its pitch comes from. The amp envelope’s main input matches the oscillator’s colour, so it’s shaping the oscillator, and its gate and velocity inputs come from the track.

From the community

Drambo Bites Ep. 1: Building a Simple Synth - Daveypoo, The Mobile Music Minstrel

Daveypoo: The Mobile Music Minstrel

The three-minute synth build the official docs recommend: an oscillator, an amp envelope, a filter and a filter envelope. Filmed on 1.x in April 2020.

Drambo - How To Make & Save a Synth From Scratch - Beginner Friendly Tutorial

The Sound Test Room

A synth from scratch – oscillators, filter, LFOs and effects – then saved as a preset. From June 2022.

10.2Basics

Insert a filter

Set the oscillator to SAW for a bright sound with plenty for a filter to work on. The filter has to sit between the oscillator and the amp envelope.

  1. Put your finger on the AMP ENV header and slide it slightly to the right until a gap opens with a blinking + in it. Let go.
  2. Tap the + in the gap and choose Filter from PROCESSOR / FILTER.
  3. Play with Cutoff and Resonance. LP12 — a low-pass with a 12 dB per octave slope — is a fine type to start with.

Drambo made every connection for you: the filter takes the oscillator, and the amp envelope now takes the filter.

From the community

Drambo Bites Ep. 1: Building a Simple Synth - Daveypoo, The Mobile Music Minstrel

Daveypoo: The Mobile Music Minstrel

The three-minute synth build the official docs recommend: an oscillator, an amp envelope, a filter and a filter envelope. Filmed on 1.x in April 2020.

Drambo - How To Make & Save a Synth From Scratch - Beginner Friendly Tutorial

The Sound Test Room

A synth from scratch – oscillators, filter, LFOs and effects – then saved as a preset. From June 2022.

10.3Basics

Give the filter an envelope

A filter that opens and closes with each note sounds far more alive. The envelope has to come before the filter, because modulation only flows left to right.

  1. With the same gesture as before, insert Env AD from MODULATOR / ENVELOPES between the oscillator and the filter.
  2. Nothing changes yet: the envelope is violet and no input is violet, so it isn’t connected to anything.
  3. Tap the filter’s Cutoff knob. Connection mode starts and shows the outputs you can use.
  4. Tap the envelope’s output socket. A new knob appears beside Cutoff: the amount the envelope moves it.
  5. Turn the new knob up, and shape the envelope’s attack and decay.

To back out while choosing a source, tap the knob again. To remove a modulation later, double-tap its amount knob and choose Remove. See Modulate a knob.

From the community

Drambo Bites Ep. 1: Building a Simple Synth - Daveypoo, The Mobile Music Minstrel

Daveypoo: The Mobile Music Minstrel

The three-minute synth build the official docs recommend: an oscillator, an amp envelope, a filter and a filter envelope. Filmed on 1.x in April 2020.

10.4Basics

Add a second oscillator and a mixer

Two slightly detuned oscillators make a fuller sound. Adding the second one shows the limit of automatic connections, though.

  1. Insert another Oscillator between the first oscillator and the envelope.
  2. Detune them a little with the Octave and Tune knobs. You only hear the new oscillator: nothing is connected to the first one any more.
  3. Insert a Mixer from the MIXER group before the filter. Now you hear nothing at all — the filter has switched to the mixer, which has no inputs yet.
  4. Tap the + on the mixer and tap the first oscillator’s output. Do the same for the second.
  5. Balance the two with the mixer’s level knobs.

From the community

Drambo - How To Make & Save a Synth From Scratch - Beginner Friendly Tutorial

The Sound Test Room

A synth from scratch – oscillators, filter, LFOs and effects – then saved as a preset. From June 2022.

10.5Basics

Polyphony and drive

You now have a two-oscillator subtractive synth with a filter envelope. Two more changes make it playable and a little dirtier.

  1. Set the instrument’s polyphony — the Voices value — to 3, and play chords.
  2. Add a Shaper from the processors’ shaper and distortion category at the end of the rack, and turn up its amount.
  3. Drag the Shaper header to the left of the filter. Distortion before a filter sounds quite different from distortion after it.
  4. To get rid of a module, swipe its header downwards until it vanishes.

Polyphony carries through the patch: every module after MIDI to CV now runs once per voice. See Polyphony, stereo and CPU.

10.6Intermediate

Wrap it in an Instrument rack and save it

Packing a patch into an Instrument rack turns it into one module you can reuse, save as a preset and show in a compact view.

  1. Hold the oscillator’s header until it turns green — the start of a selection.
  2. Choose Select All, then Cut. The modules move to the clipboard.
  3. Add an empty Instrument rack from GENERATOR / DEVICE.
  4. Inside it, tap the red + and choose Paste in the bottom-left corner of the library browser. Your synth is now inside the rack, and the rack passes it all the inputs it needs.
  5. Tap the icon in the rack’s top-right corner to switch to compact view.
  6. Tap the Instrument label, choose Presets, pick or create a folder, tap Save, type a name and confirm.

To keep a module out of the compact view, open its menu and choose Hidden in compact view. There is more on racks in Instrument racks, Compact view and Presets.

From the community

Drambo - How To Make & Save a Synth From Scratch - Beginner Friendly Tutorial

The Sound Test Room

A synth from scratch – oscillators, filter, LFOs and effects – then saved as a preset. From June 2022.

Drambo by BeepStreet - Racks, Presets, and Layers

Ben Richards

What a rack is, saving and organising racks with sections, labels and compact view, and building layers. Filmed on 1.x in April 2020; preset selectors on rack headers only arrived in 2.48.

10.7Intermediate

How pitch works

Pitch travels through Drambo on pitch signals — the sockets with a note symbol. A value of 0 is C2 (130.8 Hz), and each step of 1/8 (0.125) is one octave up or down, so the range 0 to 1 covers eight octaves.

Most pitch-related knobs default to 0, which means “follow the incoming pitch exactly”. If a patch has drifted out of tune, double-tap the pitch knob and reset it to its default.

ChangePitch signal
One octave0.125
Two octaves0.25
Eight octaves1
10.8Intermediate

Key tracking

A module without a pitch input — a filter’s Cutoff, for example — can still follow the keyboard. Modulate the parameter with the track’s pitch signal, from MIDI to CV. With the modulation amount knob turned fully right, it tracks the keys 100%; less gives partial tracking.

From the community

  • For a filter that follows the keyboard exactly, modulate its cutoff with the pitch signal from MIDI to CV. Forum users suggest a base frequency of 130.8 Hz, which is C2 and 0 in Drambo’s pitch signal, with the pitch modulation at 100%. One octave is 0.125 in that signal. via BeepStreet forums: key tracking, October 2026
10.9Intermediate

Glide and portamento

Glide makes the pitch slide from one note to the next. It takes two changes.

  1. Open the track menu and turn off Retrigger in the MIDI section, so overlapping notes don’t restart the gate.
  2. Add CV Glide from MISC / UTILITY at the very start of the track’s rack, so every module after it gets the gliding pitch.

Overlap notes in the sequencer — longer gates, or ties in auto-advance entry (Auto-advance entry) — and the pitch glides between them.

From the community

Drambo by BeepStreet - Manual Connections, Modulation, and some fun modular ideas

Ben Richards

How Drambo connects modules for you, how to patch by hand, stacking modulation sources and reading the oscilloscope. Filmed on 1.x in April 2020; the patching ideas still apply.

10.10Advanced

Ring modulation, sync and unison

Classic synth techniques are usually one module away in Drambo.

Ring modulation
It’s just two signals multiplied. Use the Multiply module from the MATH group.
Oscillator sync
Connect an oscillator’s gate input to the sync source — another oscillator, for instance.
Unison and parallel processing
The Unison module spreads a signal over several voices, each modulated separately — a powerful way to build big sounds or banks of effects from a few modules. See A moving filter bank from a few modules.

From the community

  • Clicks at the start of notes? Put a Gate Declicker before the amp envelope. Forum users explain that it holds each gate until the next zero crossing, which delays the note by under one cycle. That is harmless for most sounds, but worth knowing when timing is critical. via BeepStreet forums: No more clicking envelopes, 2022

MASSIVE SOUNDS - New DUAL OSCILLATOR with Exp FM - Drambo Tutorial 114 (iOS)

SoundForMore MusicTech Tutorials

A 22-minute look at the Dual Oscillator’s waveforms, cross-modulation and FM. It went up in September 2026, a month before 2.57 brought the module to everyone, so it may show a pre-release build.

BeepStreet Drambo v2 - Demo / Tutorial 101: Macro Oscillator (Mutable Instruments Plaid)

SoundForMore MusicTech Tutorials

The Macro Oscillator added in 2.45, based on Mutable Instruments’ code: its engines, chords, speech and random modulation. From August 2025.

10.11Advanced

MPE

Drambo handles MPE as naturally as polyphony and stereo: each note’s expression travels on its own voice.

  1. Add an empty Instrument rack.
  2. Open its menu and set Mode to MIDI.
  3. Switch on the MPE setting.
  4. Build your instrument inside it.