Doepfer

hi
yes it's a littlebit academic :)
i'm using my doepfer in combination with a argon-krypton laser to make visuals :)

the thing i'm looking for is a static wide band 90° phase shifter (90° shift from 40Hz-1kHz)



/martin

  ----- Original Message ----- 
  From: Florian Anwander 
  To: Doepfer_a100@yahoogroups.com 
  Sent: Monday, December 27, 2010 11:48 AM
  Subject: Re: [Doepfer_a100] how many stages


    
  Hi Martin

  either me do not understand what you are asking for, or you do not 
  understand that the basic principle of an allpass filter IS the phase 
  shift. It is the reason why someone is building an allpass filter.

  Or do you mean "phase distortion" as: deviation of the "real (measured) 
  phase shift over frequency" from "the ideal phase shift over frequency"?

  If the latter is the case: I fear there is no voltage controlled allpass 
  filter that suits your (a littlebit academic) requirement. Simply 
  because you will not be able to trim 12 variable stages to exactly the 
  identical characteristics. You should also obey, that the page you are 
  quoting speaks about a static phaseshifter!

  From the musical and sound-engineering approach, this kind of 
  phasedistortion is irrelevant.

  Florian

  martin sörensen schrieb:
  > i was hoping for a wider bandwith
  > with less phase-distortion
  > 
  > something like figure 5 in this article
  > http://webpages.charter.net/wa1sov/technical/allpass/allpass.html
  > 
  > 
  > /martin


  

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