A touch controller for your modular synth

Gliss is a touch controller for your modular synth.

We built Gliss using the same high-precision capacitive touch sensing technology that we developed for the Trill touch sensors, meaning that Gliss offers superb touch control that brings physical interaction into your synthesiser setup. But that’s not all Gliss has to offer: It’s also a powerfully practical tool for generating and managing control voltages in your modular system.

Gliss is available on the Bela shop, as well as a network of worldwide distributors.

Table of contents

  1. Gliss touch control
    1. 4 modes of touch control
    2. A universe of customisation
  2. Control mode overview
    1. Control type
    2. Latching
  3. Record mode overview
    1. Control Type
    2. Playback mode
      1. Loop
      2. Trigger
      3. Clock
      4. Wavetable
      5. Waveshaper
  4. Signal mode overview
    1. Scaling
    2. Clipping
    3. Envelope detector
    4. CV input block diagram
    5. Audio input block diagram
  5. Notes mode overview
    1. Keyboard
    2. Sequencer
  6. Hardware
    1. Choose your ideal orientation
    2. Tech Specs
  7. Where to buy

Gliss touch control

For a full explanation of every aspect of Gliss, check out the video manual above or download the Gliss User Manual. Below is a light and visual overview of some of the basic features of the module.

4 modes of touch control

Gliss is a touch controller with four modes:

  1. Control. Generate CV and gate signals based on your precise finger position and touch size (how hard you press on the Touch Strip).

  2. Record. Draw waveforms directly into your system and record gestures of up to 60 seconds, then play it back in a variety of ways (like looping to make a custom LFO, triggering it as an envelope, and much more).

  3. Signal. Along with visualising any signal, you can scale, offset and smooth CVs performatively, outputting the processed signal, an envelope of the input, or both.

  4. Notes. Five notes at fixed, user-configured voltages that can be used as an expressive keyboard with five touch-sensitive buttons, or as a step sequencer that’s played using an input clock signal.

A universe of customisation

As mentioned above, to read about all of Gliss’s capabilities check out the Gliss User Manual. The Menu is where all the customisation of the modes is configured. From the Menu you can change each Mode’s settings, as well as move between Modes. Here is how to access the Menu and the Global Settings.

Along with the mode settings you can customise the voltage range for the Input and Outputs, specific to each Mode. This means that you can ensure that your output signals will always be in the perfect range for where you want to use them.

Control mode overview

Control mode allows you to generate CV signals with the touch of a finger. The available settings in Control mode are summarised below.

Control type

This diagram shows the three touch different ways you can split the touch strip (Selector 1). From left: Single Slider, Dual Slider, Dual Touch. The values sent to each output in each case are illustrated in the table below:

Control Type Top Output Bottom Output
Single Slider Position Size
Dual Slider Top position Bottom position
Dual Touch Top size Bottom size


The latching selector determines whether and how the output values corresponding to the finger’s touch and position are automatically latched when releasing the finger, according to the following table and illustration

Latching setting Latches position Latches size
Unlatched No No
Latched Yes Yes
Latch Position Yes No

Latching position only can be useful when sending the size output to the gate input of an envelope generator.

Regardless of this setting, the current position and size values are latched when pressing the button or receiving a trigger signal into the input. Pressing the button or receving a trigger signal when there is no finger on the touch strip unlatches any values currently latched.

Record mode overview

Record mode allows you record in gestures up to 75 seconds in a variety of different ways. These diagrams clarify the five different playback modes enabling the creation of LFOs, envelopes, looped sequences and much more. The available settings in Record mode are summarised below.

Control Type

This selector works just like in Control mode Refer to the corresponding section above for details.

Playback mode

Each playback mode has a specific way of controlling the recording and playback of the gestures. A gesture recorded with one mode can be played back in a different mode.


When using Loop playback, you can start recording a gesture up to 75 seconds in length by placing your finger on the Touch Strip. When you lift your finger, Gliss will play back the recorded gesture indefinitely. Overwrite your gesture at any time by placing your finger on the Touch Strip and recording a new gesture. A trigger signal into the input or a press of the button will reset the LFO to the beginning. A press and hold of the button will erase the stored gesture.


When using Trigger playback, the gesture will play once when the Button is pressed or when a trigger signal is received in the Input. This way, your recorded gesture can act like an envelope with a custom shape.


Clock playback allows you to record gestures and synchronises them with an external clock signal in the Input. When using Clock playback you can record different gestures, one after the other, lifting your finger in between each one. Tap the button to start recording (taps will be synched to the next clock tick), tap again to stop the recording and start playback of the loop. Triple click the button to erase the stored gesture.


Wavetable varies the playback speed of the recorded gesture at audible frequencies. The pitch or frequency is determined by sending a volt per octave signal into the CV input. This turns Gliss into a voltage-controlled wavetable oscillator: the gesture you record is the waveform, and the CV input will determine how fast that gesture is played back.


Waveshaper playback means that you can record a gesture, and then scrub through it using input voltage. In waveshaper playback, the input range is mapped to the gesture length. For instance, with an input range of -5V to +5V, a -5v input will correspond to the beginning of the gesture, a 0V input will correspond to the middle of the gesture, and the +5V input will correspond to the end of the gesture. This means that using input voltage you can play different parts of your gesture.

Signal mode overview

Signal mode functions as a visualiser for signals in your modules case. You can also clip, scale, offset, and smooth CV or audio signals, ready to be passed around your system. The available settings in Signal mode are summarised below.


To scale and offset this input signal, place 2 fingers on the Touch Strip. A gold point will appear under your top finger (representing the maximum scaled voltage level) and a gold point will appear under your bottom finger (representing the minimum voltage level). With 2 fingers on the Touch Strip. Slide these points to scale your signal. You’ll see the animated point representing your input moving between your fingertips.


In active Signal Mode, press the Button to activate clipping. When clipping is enabled, the Button will be red. With clipping enabled you can set the minimum and maximum clipping points by sliding your fingers to move the red points on the Touch Strip. This selects a portion of your input signal to pass through to the output.

Envelope detector

This diagram shows the effect of envelope detector on a pulse input. Differing levels of envelope decay produce different envelope signals. The envelope signal is shown in green.

CV input block diagram

This diagram shows the various stages of processing when dealing with a CV signal input.

Audio input block diagram

This diagram shows the various stages of processing when dealing with a audio signal input.

Notes mode overview

Notes Mode turns the Touch Strip into a set of tuned notes. These notes can be played like a keyboard that you play with your fingers (with expressive glissando and vibrato), or like a sequencer where the notes are triggered one at a time by an incoming clock signal (with the behaviour of each step customisable). The available settings in Notes mode are summarised below.


Setting Notes mode to be a Keyboard means that you can play back fixed voltages on the Touch Strip. The voltage of the active note will be sent out the Top Output, and the touch size of your finger will be sent out the Bottom Output. You can play with vibrato by wiggling your finger vertically, and glissando by sliding continuously between notes. Tuning of the notes is possible via a v/octave source or directly via the touch strip.


Setting Notes to be a Sequencer means each of the notes becomes a step in a sequencer. Connect a clock source to move the sequencer forward. Steps can be active, held, muted or skipped.


All Gliss hardware design files are licensed under a Creative Commons Attribution Sharealike 3.0 license (or CC-BY-SA), meaning they can be freely reused and remixed with attribution, provided modifications remain open source. This is a license we use with many of our other products. Gliss firmware is the code that’s flashed on each Gliss module. Gliss firmware is licensed under the GNU Public License, or GPL. All project files relating to Gliss can be found here:

Choose your ideal orientation

Gliss is a slim 4HP module that features a capacitive Touch Strip, as well as one Input, two Outputs, and a physical Button. Gliss comes configured with the Input, Output and Button at the top, but because we want to offer maximum flexibility, we include a second faceplate that allows you to change Gliss’s orientation. This means you can change your mind later about where to put your controls, or that each Gliss you own is configured for where it lives in your modular system.

Tech Specs

For the full explanation of all Gliss functionality, download the Gliss User Manual.

  • Width: 4 HP
  • Depth: 27mm
  • +12V: 150mA
  • -12V: 30mA
  • Voltage rating: Input and outputs are ±10V safe. Usable range for both input and outputs is -5V to +10V

Where to buy

Gliss is available on the Bela shop, as well as a network of worldwide distributors. If you want to be the first to know when it’s available, make sure to subscribe to the Bela Newsletter.