Gates v Triggers in Eurorack

[jshell]

While reading through some of the discussion about the Circuit Abbey G8 clock divider, I noticed that some of the discussion (and demos in the video) differentiated between a Gate mode and Trigger mode.

What is the difference? I tried searching with Google but most of the answers I found stated that this varied between manufacturers and systems. So specific to the Eurorack format - what is the difference between a gate and a trigger (and also just a square wave from an LFO)?

[theewiper]

viewtopic.php?t=47124&highlight=gates+triggers

[BrotherTheo]

A gate is a digital signal originally meant as a key down signal from a keyboard. Today it is more than that, but it's still a signal that stays high during an event or state. The G8 for example: an output (in gate mode) will stay high until a clock makes it change state, then the output will go low and the next output goes high.

A trigger is a narrow pulse, usually 2-10 milliseconds in duration, that shows an event occurred. Keyboards of old would output both gates and triggers for key down events.

Gates and triggers are interchangeable for some modules, like clock dividers that just look for the rising edge on their input. Other modules like ADSRs are meant for a gate signal, although a trigger is also valid and useful.

I hope that helped.

--Brother Theo

[FetidEye]

a trigger is a short pulse. useful for triggering AR (attack release) envelopes for drums and other.

a gate is like a key pressed on a keyboard. press and hold = on, let it go =
off. useful for ADSR envelopes in combination with CV.
2 gates next to each other form 1 long gate. (?)

a squarewave lfo can be used as a gate.

[jshell]

Thanks for the answers. That's what I thought, but I just wanted to be sure.

And when things talk about 'clock signals', is that typically like a trigger?

[maudibe]

Yea a clock is like a trigger, but by its nature is occuring at regular timed intervals.

So to sumise:

Gate is 'long' and features a on event, a hold time, and an off event
Trigger is a very short pulse that gives a on event
Clock is a short pulse that happens at a predetermined period tick-tick-tick

Clocks triggers and gates can all be combined by something like the Bytom to give groovy pulses and rhythmic doodah.

A trigger or clock into an ADSR is going to make the sustain portion pretty redundant. A trigger input to an AR module is going to give a ping type response.
A gate into an ADSR will allow you to use the full cycle of the envelope.
A gate into an AR will just give you an AR response....

I think I got all that anout right

Play and all will become clear.

[jshell]

Ah! That helps a lot, particularly for understanding the Signal-In versus Trigger-In on the Function alongside the two Clock outputs of the Wogglebug.

[negativspace]

Gate = long trigger.
Trigger = short gate.

That's a bit oversimplified, but it should illustrate the point.

[Rayek]

I was a bit confused by this too.

Correct me if I'm wrong, but something looking for a clock pulse or a trigger will just look for the rising voltage and ignore the fall, meaning that a clock/trigger in can be anything from a square wave, a gate, or a narrow pulse, so long as the rise is above a certain voltage. This isn't always true, from what I've heard, as there are some problems with the Quadra Expander's EOC output when the envelope is on a really fast attack/decay, so the pulse is narrower than is detectable by the module it's trying to clock.

[maudibe]

there are some problems with the Quadra Expander's EOC output when the envelope is on a really fast attack/decay, so the pulse is narrower than is detectable by the module it's trying to clock

That's not a problem - its a feature

[Rayek]

That's not a problem - its a feature

Ha

I just noticed that people were complaining about it in that thread. It makes sense to me (Can't wait to get my Quadra + Expander)

[maudibe]

Yea.... that fast trigger is probably just a function of the super fast envelope. ? Fix... slooooow downnnnn

[ersatzplanet]

In the olden days (God I have used that phrase a lot on Muffs...) your keyboard would produce a gate and a trigger. An ADSR EG would receive both of them and would do AD then S as long as you held the key down (the gate would handle this) and R when the gate was removed (let up on the key). If you didn't let go of the key and hit another instead (like doing a trill for instance) the ADSR would do the AD part over again starting from the S level (the trigger telling it to start again). This is why all those fusion players from those days had such mad chops - you could be sloppy and still would get a "new" note. There are many ADSR modules out there now with both a gate and trigger input on them (the Doepfer ones call the trigger "Retrigger"). Like a previous poster said, in many cases with multiple gate sources a EG will only see one large gate when many are present at once. A trigger on top of the gate will re-fire the ADSR to compensate for this. Of course the Sustain level will have to be NOT full on to make it noticeable. If the sustain is up all the way basically the D is nonexistent.

[daverj]

Trigger = START
A short pulse that starts something

Gate = ON
A longer pulse where the time it is high usually represents the length or duration of an event.

Clock = a repeating pulse used to convey a time period, such as a beat, or note time, or a fraction of those (there might be multiple clocks pulses within a certain time period). A trigger, gate, square wave oscillator, or any other source of a repeating pulse can be used as a clock.

[carvingcode]

Reviving this thread with a slight hijack:

In a eurorack system, without the use of a keyboard to create the gate (on-hold-release), what module combinations are used to recreate this? Example: Rather than a series of long quarter notes, how do you create a series of eighth note - eighth note rest?

Thanks.

[JohnLRice]

Reviving this thread with a slight hijack:

In a eurorack system, without the use of a keyboard to create the gate (on-hold-release), what module combinations are used to recreate this? Example: Rather than a series of long quarter notes, how do you create a series of eighth note - eighth note rest?

Thanks.

I'd think a square wave / 50% duty cycle pulse would do that. A 25% duty cycle pulse would give you a sixteenth note followed by a dotted eight rest and a 75% duty cycle pulse would give you a dotted eight note followed by a sixteenth note rest etc.

[Ish]

Reviving this thread with a slight hijack:

In a eurorack system, without the use of a keyboard to create the gate (on-hold-release), what module combinations are used to recreate this? Example: Rather than a series of long quarter notes, how do you create a series of eighth note - eighth note rest?

Thanks.

4ms' expander for QCD allows continuous control over the gate's pulsewidth (via knob and CV).

http://www.4mspedals.com/QCD/qcd_exp_final_frontdc.jpg

[midiguru]

there are some problems with the Quadra Expander's EOC output when the envelope is on a really fast attack/decay, so the pulse is narrower than is detectable by the module it's trying to clock

That's not a problem - its a feature

I've noticed a different problem on another Intellijel module, the Planar. It has a button labeled Gate, but I've found this button can't be used reliably as a trigger. It will work fine for gating an ADSR, which is I guess what it's intended for. The problem is, for reasons to do with the design of the hardware, the button bounces or stutters sometimes when pressed. The result is, if you try to use it to advance a sequencer to the next stage, the sequencer will sometimes see the bounce as two rising edges (because it's looking for a trigger, not a gate), and will skip ahead by two stages.

[RLK]

Trigger = START
A short pulse that starts something

Gate = ON
A longer pulse where the time it is high usually represents the length or duration of an event.

Clock = a repeating pulse used to convey a time period, such as a beat, or note time, or a fraction of those (there might be multiple clocks pulses within a certain time period). A trigger, gate, square wave oscillator, or any other source of a repeating pulse can be used as a clock.

Thanks.
I'll admit having had mild confusion with this.
Maybe due to having a Doepfer A-162 trigger Delay early on.
Given the duration of a signal can last up to 10 seconds with this module, does that make it a trigger delay/gate generator?
That fact that it's a square wave output, it seems its generating delayed gates of various lengths more so than triggers.

[MuffTickler]

ty for the post

[MuffTickler]

Does gate go on cv channels?

[Bhola]

Does gate go on cv channels?

Gates & triggers are CV messages so yes. It just depends what kind of CV you want to feed into your cv channel.