Chapter 11. Instrument Editor

Table of Contents

11.1. General
11.1.1. Envelope Parameters
11.1.2. Gain and Mute Group
11.1.3. Filter Parameters
11.1.4. Pitch Shift Parameters
11.1.5. MIDI Out Settings
11.1.6. Hi-Hat Pressure Group
11.2. Layers
11.2.1. Components
11.2.2. Layers
11.2.3. Sample Selection
11.2.4. Controls

Figure 11.1. The Instrument editor General view

The Instrument editor General view

The Instrument Editor is located in the Instrument Rack in the lower right corner of Hydrogen, which can be shown or hidden via the View option in the Main Menu or via the corresponding button in the Main Toolbar. The Instrument Rack does either show the Instrument Editor or the Sound Library depending on what is chosen in the View option in the Main Menu or the corresponding buttons at the top of the Instrument Rack.

11.1. General

When clicking the General button in the Instrument Editor you can adjust several parameters that apply to the particular instrument (and all its layers) selected in the Sidebar of the Pattern Editor.


It's important that you understand Drumkit Concepts and a couple of basic concepts of sound synthesis described in the Glossary in order to continue on. To ease reading, several of the latter concepts are linked in the text.

11.1.1. Envelope Parameters

Four rotaries are displayed. From left to right: "ATTACK", "DECAY", "SUSTAIN", and "RELEASE".

When a note associated with this instrument is triggered, its volume is run through an ADSR Envelope. Its particular settings can be adjusted using the envelope parameters located right below the instrument name.

  • Attack: the amount of time that the volume of the sample goes from 0 to the full velocity of the note. If the value is 0, the sample will play back immediately at full velocity.

  • Decay: the amount of time for the volume of the sample to go from full velocity down to the sustain volume. If the value is 0, the sample will immediately skip from the full velocity to the sustain volume.

  • Sustain: the volume to play the note after the decay phase is over and until the note is released. If set to 0, the note will be silent. If set to 1.0, the note will play at full velocity.

  • Release: the time to fade out the note from the sustain volume back down to 0 (silent). If set to 0, the note will fade out in the minimum amount of time (about 5 ms). If set to 1, it will fade out for the maximum time available.

    Note, however, that this only affects notes for which you set a note length smaller than the underlying sample length (see Section 9.2). All other notes are played back till the end of the sample without reaching the release phase.


All transitions between the individual ADSR phases are done using exponential functions.

The Attack, Decay, and Release parameters are all set by the number of audio samples. This means that the time changes depending on the sample rate of your sound card. The max time for each of them is 100,000 audio samples (type. 2.27 sec at 44.1 kHz).

If the sample is shorter than the times that you specify, the sample will end, regardless of which phase of the ADSR it is in. If the note is sustained, it does not draw out the note while you are holding it. It only holds the gain (volume) parameter during that time.

11.1.2. Gain and Mute Group

In the upper half there is a display showing "1.00" (left) next to a rotary titled "GAIN" (middle) and a display with corresponding decrease and increase buttons (right) titled "MUTE GROUP". In the lower part there are two checkboxes: "AUTO-STOP-NOTE" (left) and "APPLY-VELOCITY" (right).

The Gain adjusts the overall volume of all samples associated with this Instrument. This Gain is applied in addition to the one you set for each layer and before the one that is set in the Instrument Channel Strips. If the set to 0, the instrument will be silent. If the Gain is 1.0, the volume of the samples will not be adjusted. If the Gain is set higher, the samples will be amplified.


It is very easy to set the Gain too high, causing your sample to clip. Remember to test the Gain with full-velocity notes. If you clip your signal here, it will only get worse as Hydrogen processes it.

Hydrogen provides more Mute Groups than you know what to do with (over 256). A Mute Group is a grouping of instruments which's playback is mutually exclusive - only one instrument of the group may be playing at a time. If one is playing and another instrument in the group is triggered, the former will immediately be silence (muted) and the latter starts playing. This is useful, especially, for instruments like hi-hats where the opened and closed sound are incorporated into the drumkit as different instruments.

If the Mute Group is set to Off, then the instrument is not part of any mute grouping. If the Mute Group is set to any number, then that is the group that the instrument is a part of. To set other instruments into the same grouping, set their Mute Group parameter to the same number. (For example, to group all the high-hat instruments, you can set all their Mute Group parameters to 1. To have a snare drum Mute Group, set their Mute Group parameters to 2.)

If the Auto-Stop-Note box is checked, Hydrogen will immediately stop any playing samples belonging to this instrument whenever the instrument is re-triggered, e.g. by another note.

This option is particularly useful when you are using long samples like a crash or some existing audio that you have sampled (like a looped voice in a dance/electro song). For the crash you will need to use the Auto Stop-Note when you are sequencing multiple notes in fast succession and want to make it sound realistic. If you do not check this option the cymbal will start to sound like multiple cymbals instead of only one (since the sample of each individual hit will be played completely). For the voice sample this option is useful if you are trying to get that 'stuttering' effect.

The Apply Velocity box lets the user decide whether Hydrogen should apply the note velocity to the sample being played.


The note velocity can set it the Note Properties Editor.

When activated, Hydrogen will apply the note velocity to the sample gain in addition to e.g. the layer gain, the instrument gain, the component gain, or the instrument volume. (A full list of all contributions can be found in Gain). If all the layer samples are normalized, this option should be used.


By default this option will be selected as this is the way older versions of Hydrogen used to work.

When not activated, the note velocity will only be used to select the sample to be played, but the sample gain itself will not be changed. This is useful for set of samples that already have their gain "hard-coded".

11.1.3. Filter Parameters

From left to right: a button titled "BYP", a rotary titled "CUTOFF", and another one titled "RESONANCE".

The filter used in here is a low-pass resonance filter. If you don't wish to use is, click the BYP button (bypass) so that it's red. If it's not red, then the filter is active. The cutoff parameter adjusts the cutoff frequency for the filter. The resonance parameter adjusts how much to boost to provide at the cutoff frequency. If the resonance is set to 0, then the filter is just a simple low-pass filter.


The cutoff frequency of the filter varies with the sample rate of your audio card. The range of the knob 0 to 1.0) is optimized for a 48,000 kHz sample rate.

11.1.4. Pitch Shift Parameters

From left to right: a display showing the total pitch and three rotaries titled "PITCH", "FINE", and "RANDOM".

The first two knobs control the pitch shift offset. You can use it to change the tuning of the instrument. Pitch is the Coarse control and has quantized steps of half-tones from -24 to +24. Fine is the Fine control and has quantized steps of cents of half-tones from -0.50 to +0.50.

The Random parameter allows you to randomly vary the pitch of the sample every time it is triggered. The value is set between 0 and 1.0.


The pitch change is fairly small, almost always between ±1 half-steps ⨉ value. Using this sparingly can help your sequences to sound more like a real drummer.

11.1.5. MIDI Out Settings

Two displays with corresponding decrease and increase buttons. The left one is titled "CHANNEL" and the right one "NOTE".

Hydrogen is capable of generating MIDI messages that you can use to trigger any external MIDI device or application. To do this, you need to configure the MIDI output Channel and Note for an instrument.


In order to enable MIDI output, the channel of an instrument must be set to a value other than off, like 10, and the instrument must contain at least one sample. Having just an empty one is fine.

From now on every time a note is played for that instrument (in the Hydrogen sequencer) a MIDI message will be sent to your external app/device and trigger a sound. This way you can use Hydrogen as a pure sequencer for other apps, or combine the internal Hydrogen sampler with multiple external apps/devices.


By enabling Use output note as input in the MIDI system tab of the Preferences dialog the number specified in the Note field will also be used to associate the current instrument with the corresponding incoming MIDI messages.

11.1.6. Hi-Hat Pressure Group

Three displays with corresponding decrease and increase buttons titled "HH PRESS. GRP", "MIN. RANGE", and "MAX RANGE" (from left to right).

The hi-hat is a particular instrument of the drumkit as its sound can be changed by pressing the foot pedal.

For e-drum owners, the hi-hat pressure group enables to group different hi-hat instruments together, for example closed, half closed, fully open.

Pressure Group: you can assign more instruments to the same group. You can create many groups. For example one group for the different opening levels of a hi-hat when playing the top of it, another group when playing the edge. Another example: timpanis - create a group for each timpani and the pressure will change the note.

Range: set the minimum and maximum pressure for each instrument. Each instrument of a given group should seat in its own separate pressure range. The range will decide at what pressure level the instrument will be played. For example, if your closed hi-hat has range from 0 to 20, when the hi-hat pedal is pressed between 0 and 20 the closed hi-hat is played.