True gate to trigger conversion

I am trying to trigger my Alesis D4 drum machine. It has inputs for hardware triggers. And by triggers I mean just a voltage spike. There are a couple sequencer modules that try to output triggers, but they are really just pulse waves. A lot of outputs on modules labeled as triggers are pulse waves, or gates. The few gate to trigger modules I found are still gates, or they don’t translate the gates accurately. One outputs two triggers per pulse, 0 - 5 and 5 - 0 transitions. One labeled zero crossing only outputs a trigger on the 0 - 5 edge which is good but it doesn’t seem to do it for each 0 - 5 transition reliably. I am outputting these out through an expert sleepers ES-8. I am doing all my checking with scopes in VCV. Any suggestions?

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Count Modula G2T will take a gate or trigger pulse and output a 1ms trigger at the start, end or both start and end of the incoming gate/trigger depending on what you want.


Thanks! My D4 is drumming away. Your 8 Step Trigger Sequencer to G>T to audio out to my ES8 and to your 4 channel scope. The scope isn’t showing all the triggers, but they are definitely there. This works.

If it’s a scope in Rack, a 1msec trigger can be too short to see, depending on the display refresh rate.

Thanks! Yup, scope in Rack.

I’m idly curious… If you were to use ratcheting (as with a module like hexaquark (VCV Library - Geodesics+Vult Hexaquark), would your setup be able to keep up?

In case you don’t already, you might want to be aware of RGate. Can shorten a Gate to a 1ms Trigger, and works as a Divider/Multiplier which lets you sequence or perform, say, an occasional triplet into your beats. Or introduce a syncopated stumble with an uneven clock input. It’s neat :).

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why wouldn’t it?

I’m not very familiar with Alesis drum machines, but the one my daughter had (a base model, years ago) wasn’t the most reliable in registering hits from the pads - and those were being sent at human speed. So I was wondering how well one would handle ratcheting (especially at high BPM).

Submarine pg-104 (see also: pg-112) is imho the most versatile and compact choice… one 2HP instance has 4 generators that work from 0.001s to 100s and in the right-click menu you can chose the voltage range you want your signals in. 0.001 is identical to count modulas G-T conversion in the scope. if you ever have another problem in regards to pulse/trigger/gate … this is likely the solution to any of those. my ES-5 recognizes its triggers (modular), my Lyra 8 its gates, my Elektron gear its pulses.

@augment the ES-8 connects via USB or ADAT via high quality connections and outputs super stable signals. The D4 should be able to receive 16 sequences along with clock, CCs and system commands if I remember correctly. It’d be quite bad if it couldn’t handle ratcheting. That it didn’t recognise the pads of a MIDI controller is likely the same problem OP mentioned: it probably doesn’t take pulses, gates, ramps… just triggers. but even developers and manufacturers have a tendency to write “trigger” on any short, spiking signal output/generator nowadays. Modern gear is usually built to tolerate a range of signals (i.e. anything that exceeds +3 or -3 volt within 0.02s will be regarded as a trigger by a trigger input - even if its a gate from a pad pressed by hand) - older gear was built in a different mindset: any foreign signal would be kept out to protect the gear and possible on-going performance.
You can go into a bar when you’re a person wearing clothes, carrying some dinero - but you won’t get into Berghain if you look like a Pulse, a Gate, a Ramp, a Tick or other queer Square except the one they’re looking for. :stuck_out_tongue: apart from a few exceptions, you can be fairly certain that almost all quality gear from the last 30+ years will handle anything within its specs… as well as that most MIDI gear that was built recently and is sold as ‘universal’ addition to your setup… does not work within these specs. You will always need conversion. 3.3V Gates with 0.5s duration won’t work, sequencers using the same port to output pulses, triggers and gates will likely not work (because its probably 0-5 volt at best) and its quite possible that their software just doesn’t distinguish between triggers and gates, so even via MIDI you couldn’t get any sound. Expect troubles like that to pop-up when buying older gear.

The D4 likely won’t work with average MIDI-Drumpads… but its dedicated Trigger inputs are straight-forward… any 2,5$ trigger piezo soldered to a patch cable should work… besides anything else that can send a trigger (i.e.: DC-Coupled Audio-Interfaces).

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The Submarine modules are great. The PG-104 actually goes down to .00001s, which requires VCV sample rates at 176.4KHz or greater to realize. If running slower than that, then .00001s will simply be a 1 sample pulse.


Thanks for that explanation. As it happens, I was referring to the pads that came with the unit (as an electronic drum kit), but as I say, it was a cheap model and not recently purchased. In all likelihood, the issue was the pads themselves & not the head unit. At any rate, I hope the OP is off happily machine-drumming away w/o issues at any BPM.

Ratcheting… What I found is that if I sent a GATE, a square wave with an obvious duration, the D4 would ratchet the drum hit for the length of the gate. Instant drum rolls. This is why I was looking for pure triggers to avoid the rolls…