I’m trying to patch a basic impulse train voice – the trick originated with Serge’s Dual Universal Slope Generator, I think, and was extended with Mannequins’ Mangrove module.
For this to work, attack and decay times less than 1 ms are needed. At 440 Hz, for example, a total envelope period of 2 ms would leave about 0.7 ms left for silence.
BogAudio is my go-to VCV module manufacturer, for its elegant minimal design and great range of utilities. It’s AD decay has controls that go below a 1 ms attack/decay BUT when I try to set those controls less than 1 ms, the VCV scope doesn’t show the period shrinking at all, which is puzzling me.
Tides would be a candidate for this, but unfortunately it retriggers from 0 volts rather than its current amplitude state, which precludes the wonderful overtones available when the period of the envelope exceeds the period of the triggering oscillator.
You might try the one shot mode of my Venom VCO Lab
In one shot mode it generates one wave cycle for each trigger received at the sync input. The frequency establishes the width of the pulse, and it can be driven at audio rates. There are lots of options for shaping the pulse as well.
Omri has a demo/tutorial video that includes a section on one shots
The Nysthi AD envelope has always been seen as particularly fast and snappy.
If you want to get really surgical with your fast attack and decay times, Shapemaster lets you set attack and decay time precisely in Microseconds (1/1000 of a millisecond)
Thank you. It sounds like, for an impulse chain voice, I would sync a second oscillator to the fundamental oscillator so that I could set that second oscillator’s period shorter than the first; then use that second oscillator’s period as the duration to match with Venom’s One Shot mode. Do you know what the minimum duration the one shot mode can produce is? Thanks.
Thank you. I don’t know the exact limitations of the Scope, but upon further investigation, I found that Instruo’s Cnoc can go a bit below 1 ms attack and decay times. Tides 2 can go further still – maybe a half a millisecond for a total envelope period, but as I said before, it seems to retrigger from 0, which isn’t ideal for this application.
All you need is any oscillator (or other trigger source) to trigger the VCO lab sync input when in one shot mode.
VCO Lab has a hard frequency limit of 12kHz, which equates to 0.083333 msec (83.333 µsec) cycle length.
Note that at those extremes the antialiasing low pass filter will attenuate the signal. But I would be surprised if you want a pulse that short.
Also note that VCO Lab retriggers from 0.
Triggered one shot will not retrigger until after the previous cycle is complete (triggers during the cycle are ignored). This results in subharmonics if the one shot cycle is longer than the triggering wave length.
Retriggered one shot will retrigger from 0, even in the middle of a previous cycle.
Gated one shot will terminate the cycle prematurely at the end of the triggering gate.
