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Operation Notes
The EG3870 uses the inverted envelope as the default cv source for modulation. Since this is occurring at the same rate as
the regular envelope, the effect will be to bias each ADSR segment from the standard RC curve to one that is more linear or
even bent the opposite direction. The following show the attack segment with no modulation in the center. FCCW
modulation on the left and FCW on the right.
Using the Global CV Input, for example with the velocity, aftertouch or modulation wheel of a keyboard via the
MIDIverter, allows flexible expression possibilities. Plugging into the separate ADSR CV Inputs will allow even more
complex modulation.
Any external modulation source can be used here; find your favorites.
Delay function:
The range of 0-10 seconds is spaced non-linearily around the dial with the rotation center equal to 1 S.
The Delay IC will respond to the
second
gate after power up, so give your keyboard an extra tap after turning it on.
The time delay is resettable, meaning that the interval will start over every time the gate is activated as long as the
delay has not elapsed.
There are two responses of the Delay, depending on if the gate is held active momentarily or throughout the delay
period. In the first case, the delay will proceed automatically, then trigger the AD cycle, ending at the Sustain
Level.This will be held until the next Gate is applied and held as in case 2. Setting the Sustain level at 0 will give an
AD style envelope. In the second case, the envelope will proceed normally through the ADS cycle, releasing when
the gate goes low.
End of Attack (EOA)
is a 10 mS pulse with it’s rising edge at the end of the attack segment.
Half Power Point (HPP)
is a 10 mS pulse with it’s rising edge occurring where the falling envelope passes the 5V (half
power) point. It is similar to end of decay but offers somewhat more flexibility. For example it can occur during the decay
segment or release segment.
End of Release (EOR)
is a gate that goes low whenever the envelope ends.
Gate and Trigger Inputs:
Only the Gate is actually needed. If a Trigger is input and the Gate is high, then the AD portion
of the envelope will occur. Otherwise the envelope will rise to the Sustain Level only. The example below uses the Synth
Tech Morphing Dual LFO to provide both the gate and trigger, with a variable phase lock. Thus the AD portion can be
moved anywhere along the sustain “base”.