Gate in synthspeak

[oldangelmidnight]

I've got a couple of synth-adjacent devices with gate patch points. What do they do? I've got a Korg SQ-1 and a Dreadbox Epsilon both with gate in and out. Is it just a trigger signal? Can they do anything interesting with CV inputs on pedals? Would they work as tap tempo?

[ritz]

Yeah it's like a trigger. I use the gate from an Epsilon to trigger the envelope on an ARF. Might work for tap tempo depending on the pedal? Gates are often on - off - on - off at a fixed tempo is my understanding, but the Epsilon for example is more like a one-shot trigger.

You're talking about a brief little blip though when the gate is on, and then it falls back to 0, so in terms of CV control of pedals in general idk how useful it would be.

[crochambeau]

In classic synth terms the gate is opened when you press a key/pad/point whatever, and closes when you lift your finger ("open" and "closed" terms are opposite the technical terms for a switch, as it's easier to pass through an open gate) Gates are typically plumbed into envelope generators/VCA to allow signal to pass as a key is struck.

To carry on the synth aspect: in addition to the gate will be pitch CV, that is routed elsewhere and performs a different function, but the two are both used to make a note.

I would say that a periodic on - off - on - off is more of a sync signal, but since application blurs, so do terms... which echoes right into the marketing department for further confusion. So it's hard to say what it actually does on a circuit without testing it, but consider it a switch that is turned on when a particular voltage or threshold of voltage is applied, and off when that voltage drops below the threshold.

[kbit]

To reiterate and potentially address your specific questions: a gate is an on / off signal to that can be used in a variety of ways.

The term "gate" is generally distinguished from a "trigger" by taking in account the length of the on signal. A "trigger" generally refers to a quick on->off signal, which can be used to sync/clock other circuits or set off a simple attack/decay envelope. Conversely, a "gate" has a variable length. These are more lay terms than hard distinctions.

On your SQ-1 the gate length can be set by the "duty" knob in most modes. Gate length can also refer to how long you hold down a key on a synth, as crochambeau mentioned. The effects that the length of a gate has depends on where it's being sent. For example, something like an attack/decay envelope just detects the "rising edge" of a gate turning on, so no matter how long it's on the attack/decay envelope will simply cycle once. But on an attack/decay/sustain/release envelope, the sustain period of the envelope cycle is held for as long as the gate is on.

They can do things to cv inputs on pedals, but it's a simple on/off setting so it's will only really have two positions of modulation. Also wanna make sure the voltage level your SQ-1 puts out will be safe for whatever effects pedals you are using. You could potentially sync a tap tempo delay with a gate signal, but how it will work will all depend on what equipment is used.

[oscillateur]

Also, what distinguishes a trigger from a gate is essentially that a trigger defines a discrete event while a gate defines a continuous one :
- what defines the trigger is the fact that the voltage crosses a threshold (typically from 0 to a few volts), what happens after that has no importance.
- what defines a gate is the time during which the high voltage is maintained.

And gate outs have a specific voltage, often +5V but it depends on the devices.