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.

	Note
	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.

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.

	Warning
	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.

	Tip
	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 the layer gain, the instrument gain, the component gain, or the instrument volume. If all the layer samples are normalized, this option should be used.

	Note
	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".

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.

	Note
	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.

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.

	Note
	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.

Hydrogen is capable of generating MIDI messages that you can use to trigger any external MIDI device or application. To do this, you simply need to configure the MIDI output Channel and Note for every instrument. You need to have a sample loaded (an empty WAV file is fine) and make sure the proper MIDI routing/wiring is in place and you're set. As you can see this is a very flexible approach that enables you to trigger samples or sounds from multiple devices and/or apps.

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.

	Note
	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.

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.