Doepfer

ah, thanks for explaining Dieter, once again i am foiled by pesky physics!
looks like you'll sell me some of the quad lfo / vco modules then!
there's always a silver lining!
 
thanks,
 
Will.



To: Doepfer_a100@yahoogroups.comFrom: yahoo@doepfer.deDate: Wed, 29 Oct 2008 14:48:32 +0100Subject: AW: [Doepfer_a100] Let me hear your bright new ideas for future Doepfer A100 modules!




> hello,>> i'm sure this is achievable with existing modules, if it is could> someone explain how (four phase shifters?), but the other day I> decided that I could do with a module in which you can input a> waveform audio or cv and have seperate outputs in 90 deg/180/270> deg etc phases.like the quadrature modules which exist but from> an input rather than internal occillators.> a quad-phase shifter i suppose? using four seperate phase> shifters-would you be able to set them accurately enough?> diy'ers-would this be simple enough to knock up? i'm no engineer> but i can solder things together ok. sounds simple to me....but> then lots of things do that aren't. :(A 90 degree phase shift over a wide frequency range is not easy to realizebecause the phase shift of a normal phase shifter is not constant over thefrequency but depends upon the frequency! It's the function of the domefilters in the (obsolete) A-126 frequency shifter. In the A-126 we used a12-stage allpass filter to approximate a 90 degrees phase shift in thefrequency range 6 Hz ... 12 kHz with +/-2 degrees error. It's very difficultto adjust a dome filter as the phase shift of each all pass affects theothers too. It took more than 30 minutes to adjust the dome filter of theA-126.180 and 270 degrees can be achieved by intverting the signal (180) or the 90degree signal (270).Best wishesDieter Doepfer 





_________________________________________________________________
X Factor: latest video, features and more. Click here!
http://clk.atdmt.com/GBL/go/115454063/direct/01/

[Non-text portions of this message have been removed]