Revise gates and triggers section

DSP.md

@@ -122,10 +122,10 @@ You can combine the naive and FFT methods into a hybrid approach with the [overl
 
 #### IIR filters
 
-An infinite impulse response (IIR) filter is a general rational transfer function. By multiplying the denominator of the rational $H(z)$ definition above on both sides and applying it to an input and output signal,
+An infinite impulse response (IIR) filter is a general rational transfer function. By multiplying the denominator of the rational $H(z)$ definition above on both sides and applying it to an input and output signal, we obtain
 $$\sum_{m=0}^M a_m y_{k-m} = \sum_{n=0}^N b_n x_{k-n}$$
 Usually $a_0$ is normalized to 1, and $y_k$ can be written explicitly.
-$$y_k = \sum_{n=0}^N b_n x_{k-n} - \sum_{m=1} a_m y_{k-m}$$
+$$y_k = \sum_{n=0}^N b_n x_{k-n} - \sum_{m=1}^M a_m y_{k-m}$$
 
 For $N, M = 2$, this is a [biquad filter](https://en.wikipedia.org/wiki/Digital_biquad_filter), a very fast, numerically stable (assuming the transfer function itself is mathematical stable), and reasonably good sounding filter.
 

VoltageStandards.md

@@ -20,17 +20,18 @@ It is much better to allow voltages outside this range rather than use hard clip
 
 If your module is capable of applying >1x gain to an input, it is a good idea to saturate the output.
 
-### Triggers
+### Triggers and gates
 
 In Eurorack, many modules are triggered by reaching a particular rising slope threshold.
-However, because of the [Gibbs phenomenon](https://en.wikipedia.org/wiki/Gibbs_phenomenon), a digital emulation will falsely retrigger many times if the trigger source is bandlimited.
+However, because of the [Gibbs phenomenon](https://en.wikipedia.org/wiki/Gibbs_phenomenon), a digital emulation will falsely retrigger many times if the trigger source is bandlimited (e.g. by using a virtual VCO square wave as a trigger input or a hardware trigger through an audio interface.)
 
-Thus, trigger inputs in Rack should use `SchmittTrigger` from `digital.hpp` with a low threshold of about **0.1V** and a high threshold of around **1 to 2V**.
-For example, Audible Instruments modules are triggered once the input reaches 1.7V and can only be retriggered after the signal drops to or below 0V.
-Rack plugins can implement this with `schmittTrigger.process(rescale(x, 0.1f, 2.f, 0.f, 1.f))`
+Thus, trigger inputs in Rack a [Schmitt trigger](https://en.wikipedia.org/wiki/Schmitt_trigger) with a low threshold of about **0.1V** and a high threshold of around **1 to 2V**.
+Rack plugins can implement this using `SchmittTrigger` from `digital.hpp` with `schmittTrigger.process(rescale(x, 0.1f, 2.f, 0.f, 1.f))`
 
-Trigger sources should produce **5 to 10V** with a duration of 1 millisecond.
-An easy way to do this is to use `PulseGenerator` from `digital.hpp`.
+Trigger sources should produce **10V** with a duration of 1 millisecond.
+An easy way to hold a trigger for this duration is to use `PulseGenerator` from `digital.hpp` with `pulseGenerator.trigger(1e-3f)`.
+
+Gates should produce **10V** when active.
 
 ### Pitch