PROEL DSO480 - All Pass Filter; Phase Filter

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All Pass Filter
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InA Input A APF:1 0
1k00Hz Q=3.0 Allpass
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Remember–tochangefiltertypes,pressBYPASSto
bypassthefilter,andthenuseENTERtoselectthefilter
type.
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Theallpassfilterhasadjustablefrequencyand‘Q’(or
Bandwidth)controls.Theseaffectthefrequencyat
whichthephaseeffectivelyflips180°,andthe‘speed’at
whichth
istransitionoccurs.
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Thegraphshowsanallpassfiltercentredat1kHz,with
various‘Q’settings–thehigherthe‘Q’thefasterthe
transition.
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Phase Filter

InA Input A PHS:1 0
1k00Hz 150° Phase
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Remember–tochangefiltertypes,pressBYPASSto
bypassthefilter,andthenuseENTERtoselectthefilter
type.

Thephasefilterhasadjustablefrequency,andphase
shiftcontrols.Thisintroducesaphaseshiftthat
graduallychangesfrom180°abovethecentre
frequencytothespecificedvalueatthecen
tre
frequency,andtendingtowards0°belowthecentre
frequency.
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Thisgraphshowsthephaseshiftrelativetotheinput 
(ignoringprocessingdelays),in10°steps–thefilterwill
actuallyprovidehigherresolutionthanthis,operatingin
2°steps.Thefilteriscentredat1kHzinthisexample.
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