Trigger < 1 ms

lloydcole · 2015-11-11T18:27:03.687Z

Experimenting with trigger amplitudes and lengths for a project I’m working on I established that .5 ms seems the ideal length to musically ping a filter, to my ear anyhow…
I’m working on a utility module which will output triggers in certain configurations so I need to decide on a standard for these triggers. I wondered if .5 ms would be to short in any applications?
The only modules in my system which had a problem with these triggers were Meadowphysics and White Whale (I didn’t test ES). The external clock in on both modules needs a trigger 1 ms or greater.

99.9% of the time I doubt this is an issue but it got me thinking about TT. I checked, the trigger ins will see and respond to the shorter triggers, but I believe 1 ms is the shortest trigger it will output. This might be something worth looking at down the road. Especially as the ability to generate shorter triggers would add the the potential musicality of isms… I tested with 3 Sisters and Toppobrillo and both preferred shorter trigger.

murray · 2015-11-11T19:07:29.658Z

The A-100 technical details (regarded as eurorack standards doc) doesn’t say…
http://www.doepfer.de/a100_man/a100t_e.htm

But I found this forum post at muff’s

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.

https://www.muffwiggler.com/forum/viewtopic.php?p=1219942

EDIT: Aren’t triggers spec’d to simply act on the rising edge of an input signal? Does it matter?

lloydcole · 2015-11-11T19:23:53.337Z

Yes, it does, apparently. I think analogue modules will respond to any rising voltage but digi is different. Tony from Make Noise just told me that Rene and / or 4ms PEG could miss a very narrow (like .5ms) trigger.

scanner_darkly · 2015-11-11T19:34:38.437Z

another potential solution: http://www.steadystatefate.com/propagate
if i’m reading the doc correctly you should be able to get even shorter triggers: “~200us to ~100ms (<10us min with cv)”

i’ve got one, a very handy module for trigger/gate conversions and conditioning.

lloydcole · 2015-11-11T19:41:14.115Z

I have a propagate. That’s what I just did all the testing with It’s a terrific module. I wasn’t so much thinking about my project when starting the thread, rather whether or not shorter triggers could be output directly from TT…

scanner_darkly · 2015-11-11T19:44:20.046Z

yeah, never appeared to me to try it for pinging filters specifically, could be interesting with the CV control over the trigger length…

Test2 · 2015-11-11T19:44:28.399Z

software trig detection can react to a rising voltage, 0.5ms could be a concern for the module internal rate of polling new values from the dac, e.g. trig start-to-end is faster than the polling rate. digitally, trigs as short as 1/sampling rate of the dac will be possible.