FXpansion EtchRed - Manual (Page 9)

Etch audio modules and signal path 9
© 2012 FXpansion Audio
2.2 Filter1 and Filter2
Etch Red's 2 filter modules are identical, although there are minor differences in terms of controls
for linking and routing.
Power
The Power buttons for Filter1 and Filter2 allow you to activate or bypass each filter.
Key Track (Filter1 only)
The Key Track function lets you directly 'play' Etch Red's filters with notes from Reason's
sequencer or its main C V/gate inputs. It is recommended to use this function rather than the Pitch
TransMod source to modulate the Freq control because it results in perfectly accurate pitch
tracking.
For key tracking both filters together, it is necessary to activate the F1 Freq Link button.
F1 Freq Link (Filter2 only)
With the F1 Freq Link button selected, adjusting or modulating the Freq control for Filter1 results
in the same changes being applied to Filter2.
The value of the Filter2 Freq control is added to that of Filter1, so its value acts as an offset to the
Filter1 Freq value. Therefore, if you want both filters' Freq parameters to be the same, you should
set Filter2's Freq control to 0 when using the F1 Freq Link function.
Any offset between the Freq setting of Filter1 and Filter2 is preserved whenever possible. Any
offset can be temporarily lost by moving the filter frequency to the extreme minimum/maximum
positions, although it returns when moving the filter back into the main range.
Parallel (Filter2 only)
The Parallel button allows you to toggle the routing of Filter1 and Filter2. By default it is
deactivated, meaning that the routing of the filters is serial: Filter1 is placed before Filter2 in the
signal path. With the button activated, the 2 filters operate on the same input signal in parallel,
with the output being subsequently mixed after the filtering stages.
Type
Etch Red features 4 different filter models, selectable with the Type control. Each Type provides a
varied set of Mode settings and possesses different circuit-modelled characteristics. C lick the up/
down buttons to cycle through the available Types or click the display to select from a drop-down
menu. See chapter 5 for filter response curves of all Types and Modes in Etch Red.
Japan
This filter type is a classic Japanese monosynth filter based on cascaded OTA components. The
Japan filter offers a large variety of filter Mode settings: As well as conventional 2-pole and 4-pole
low-pass, band-pass, high-pass and notch filters, it also features a 2-pole peak filter response and
a number of additional combinations of low-pass, high-pass, notch and peak filter outputs which
provide a huge range of possible sonic effects.
SVF
This filter is a typical state-variable filter (SVF) design, offering 2-pole and 4-pole low-pass, band-
pass, high-pass, notch and peak filter responses using the Mode control.