[sdiy] Re: Saw phase shifter was: English lessons

[mark verbos]

oh. well then scratch that all from the record. Incidentally, didn't 
Jörgen Bergfers add that to his LFO?

Mark



Harry Bissell Jr wrote:

>Yes you can sweep the phase with CV
>
>By dependant on power supply voltages, Magnus'
>version relies on the clippling of the opamp to
>get the shift. So if the opamp does not clip politely
>or if the supply voltage changes, you will be out
>of calibration.
>
>Likewise if the Sawtooth amplitude in changes, you
>will be out of calibration as well.
>
>It would be possible to make a precision clipper to
>get
>around this problem.  If the sawtooth does not have
>fast reset time, there will be a major glitch in the
>wave. Trying to filter this without killing the normal
>reset of the saw is difficult.
>
>I think that having individual harmonics able to be
>phase shifted might be underwhelming. It could be done
>but humans are not super sensitive to pahse of
>harmonics (unless they are shifting) which would seem
>to be the point here. 
>
>H^) harry
>
>--- mark verbos <mverbos at earthlink.net> wrote:
>
>
>---------------------------------
>    wait, you can sweep the phase 360 degrees with a
>CV? That's what Imean. I thought you had to trim it in
>and leave it. Didn't you say thatit was dependent on
>power supply voltages?
>
>anyway, the Buchla thing (and he only made one like
>this, so he learnedhis lesson) as far as I understand
>it, has the root and the next 9harmonics in sine
>waves. Those sine waves can be swept 360 degrees
>andhave their volumes mixed. I think this is a big
>difference from justhaving the sines all starting at
>the same place, but maybe I'm kiddingmyself. 
>
>you're right it's not MORE important.  :(
>
>Mark
>
>
>Harry Bissell Jr wrote:
>  
>MORE importantly... (what are you saying ?)The phase
>voltage 'is' sweepable isn't it ?If you mean that
>changing the voltage changes therelative phase shift
>of the sawtooth.The neat thing would be to be able to
>sweep overmultiple cycles.I'm using sawtooth phase
>shift now.  It sounds good,but if you compare it with
>the input sawtooth itsboring. The sound would be more
>like a simple PWMwave.So what do you mean ???H^)
>harry--- mark verbos <mverbos at earthlink.net> wrote:  
>      
>more importantly, how do you make the phase
>voltagesweepable? You need to put the Buchla harmonic
>generator in MillsCollege to shame.MarkMagnus
>Danielson wrote:    
>          
>OK, now to get you back on track... remember my      
>        
>sawtooth phase-shifter? What do    
>          
>you guys think needs to be done to make it      
>        
>workable? Should a good op-amp be    
>          
>enought maybe?Cheers,Magnus       
>        
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