> Hello Dieter
>
> Am 07.04.2016 um 11:49 schrieb yahoo@... [Doepfer_a100]:
> > I had a discussion with other module manufacturers during the Superbooth and
> > we think about an expansion of the eurorack standard that includes also specs like minimum trigger length (1 ms or 5ms are under
> > discussion) and minimum gate/trigger levels. Some manufacturers voted for 3V (because they use internal controllers with 3.3V
> > supplies and want to keep the circuits as simple as possible) but I'd recommend at least 5V even if this requires
> additional level
> > shifters (for some of our modules these level shifters are 30% or more of the circuit, e.g. A-160-1/2, A-161).
> I'd vote for a threshold level as small as possible.
> The highest trigger voltages I know are 12V. To my experience even
> retriggering due to transient overshoots does not happen with such high
> trigger signals (on the usual cricuits) with a threshold down to 1 Volt.
> Looking at the 3.3V argument I'd vote for a threshold level of 2V too.
> About the minimum length I vote for 5ms, because it makes software based
> debouncing much easier.
>
> Florian

Hi Florian,

I agree if you mean the input threshold. In most of our modules there is an npn transistor at the input which has a threshold value
in the 1V range. But the output level of gate and trigger signals should be at least 5V from my point of view. In this case you are
always on the safe side. And one also have to consider that gate and trigger signals are also sometimes "abused" for other
functions, e.g. as sync input for VCOs so that the VCO starts from the same waveform position (an important feature especially for
bass sounds with low VCO frequencies), or as "on/off CV" e.g. to open a VCF or VCA. User's also mix gate and trigger signals e.g.
with A-138 (e.g. as a simple sequencer). For these applications a 2 or 3V level would be not sufficient (I don't know a VCO that
would sync with 2V only). We will see what will be the result of the eurorack manufacturers agreements in terms of these additional
specs.

Cheers
Dieter