Triggering Hermod gate messages via MIDI CC


#1

Hi,

I’m using Sonic-Pi (SP) as a MIDI controller -

https://sonic-pi.net/

I can control CV very nicely using SP’s midi_note_on and midi_note_off commands

I know about Hermod’s gate_retrig facility which will trigger a gate whenever a new note is received; very useful

But I want to be able to trigger gate messages by themselves, to trigger samples etc. Right now the only way I can do this is to use midi_note_on and then midi_note_off, which seems excessive. It also seems to limit the number of samples I can trigger in a short space of time - I think SP is having trouble with rapid on/off/on/off sequences

Is there no way to send a single MIDI command to trigger a single gate ? If so how ? (maybe MIDI CC, haven’t investigated yet)

Thanks!


#2

Update.

So I’ve found this sentence in the Hermod manual -

 A modulation pattern can be used to record and play CV or CC automation patterns, as well as recording gate sequences for drum or clock signals

which sounds exactly what I want. So I’ve set up a modulation pattern, connected the Hermod gate output to my sampler, and am now trying to ping the sound via CC messages.

I saw this -

which seems to indicate you should avoid using CC 1. But it doesn’t seem to matter what CC I use, I can’t seem to trigger the sampler. I can however trigger it if I send MIDI note on/off.

Does anyone have some advice on how to trigger gate messages via a modulation pattern and MIDI CC ? Specifically what CC to use, and whether I am missing any steps here.

I am on Hermod OS 1.03 so probably need to upgrade.

@thetechnobear ?

Thanks!


#3

sorry, I don’t really understand you problem!?

its the midi standard that notes require note on/note off… that’s not ‘excessive’ thats just the spec :wink:
its not really anything to do with hermod.

if you used CC it would be the same since, you have to send CC x =127, then CC x=0, for it to work as a trig.
(and you’d have to use a cv output rather than gate, which is a bit of a waste really)

errr, that should not be an issue, midi can accept a note off, straight after the note on… so less than a 1ms, over usb or din.

also in eurorack, the gate will turn to a trig on note on, so there no latency, and if your using something like a decay envelope, its not hanging around for the note off anyway.

for fun I did a small test using the Pyramid to send the name note over midi to the hermod, sending at 1/64 @999 bpm, it worked without a problem and creates (as expected) a drone… so I dont see any issues with hermod accepting notes quickly.

I suspect your issue is with sonic_pi?


#4

hey @thetechnobear thanks for taking time to respond :grinning:

its the midi standard that notes require note on/note off… that’s not ‘excessive’ thats just the spec :wink:
its not really anything to do with hermod.

if you used CC it would be the same since, you have to send CC x =127, then CC x=0, for it to work as a trig

I am new to MIDI. It sounds like on/off, whether via notes or via CC (127 -> 0), is the “standard” way to generate a trig, which could trigger a sample. Is that correct ? (I was assuming a single message could trigger a trig, but maybe not …)


#5

a CV trig is 0 to non-zero volts (usually something like 2v)

so if your doing midi, then the note on will take the gate to 5v (from 0v) , causing the trig,
but then it needs to drop back down to 0v (which note off does)

(as i said you could do this via CC, but the hermod cannot map CC to gate (afaik) only the CV outputs… and they tend to be handy for other things - so id stick with note on/off)

so yeah, note on/off is pretty much the normal way of triggering samples when using midi.
(also bare in mind, note on velocity can be used, you can use it to accent particular notes)


#6

That is perfect and very clear. Thank you.