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

Thu Sep 15 23:13:19 CEST 2005

From: mark verbos <mverbos at earthlink.net>
Subject: Re: [sdiy] Re: Saw phase shifter was: English lessons
Date: Thu, 15 Sep 2005 12:40:23 -0400
Message-ID: <4329A3F7.901 at earthlink.net>

> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
> <html>
> <head>
>   <meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type">
>   <title></title>
> </head>
> <body bgcolor="#ffffff" text="#000000">
> wait, you can sweep the phase 360 degrees with a CV?

Yes, that would have been obvious if you actually looked at the page and
schematic.

> That's what I mean. I thought you had to trim it in and leave it. Didn't you
> say that it was dependent on power supply voltages?<br>

He was refering to the fact that my design was pure el-cheapo, using a sad
excuse for a dual-opamp and 4 resistors. So, you can assume a few cut corners,
right? ;O)

So, the trimming procedure is to correct for a few assumption, namely the
rail-to-rail voltage - sawtooth amplitude ratio.

> <br>
> anyway, the Buchla thing (and he only made one like this, so he learned
> his lesson) as far as I understand it, has the root and the next 9
> harmonics in sine waves. Those sine waves can be swept 360 degrees and
> have their volumes mixed. I think this is a big difference from just
> having the sines all starting at the same place, but maybe I'm kidding
> myself. <br>

If under CV-control, it is cool. ;O)

Now, which Buchla module are you talking about?

PS. HTML only is bad, HTML + Plain is better, Plain is best.

Cheers,
Magnus

> <br>
> you're right it's not MORE important.  :(<br>
> <br>
> Mark<br>
> <br>
> <br>
> Harry Bissell Jr wrote:<br>
> <blockquote cite="mid20050915151107.15718.qmail at web51006.mail.yahoo.com"
>  type="cite">
>   <pre wrap="">MORE importantly... (what are you saying ?)
> 
> The phase voltage 'is' sweepable isn't it ?
> If you mean that changing the voltage changes the
> relative phase shift of the sawtooth.
> 
> The neat thing would be to be able to sweep over
> multiple cycles.
> 
> I'm using sawtooth phase shift now.  It sounds good,
> but if you compare it with the input sawtooth its
> boring. The sound would be more like a simple PWM
> wave.
> 
> So what do you mean ???
> 
> H^) harry
> 
> --- mark verbos <a class="moz-txt-link-rfc2396E" href="mailto:mverbos at earthlink.net"><mverbos at earthlink.net></a> wrote:
> 
>   </pre>
>   <blockquote type="cite">
>     <pre wrap="">more importantly, how do you make the phase voltage
> sweepable? You need 
> to put the Buchla harmonic generator in Mills
> College to shame.
> 
> Mark
> 
> 
> 
> Magnus Danielson wrote:
> 
>     </pre>
>     <blockquote type="cite">
>       <pre wrap="">OK, now to get you back on track... remember my
>       </pre>
>     </blockquote>
>     <pre wrap="">sawtooth phase-shifter? What do
>     </pre>
>     <blockquote type="cite">
>       <pre wrap="">you guys think needs to be done to make it
>       </pre>
>     </blockquote>
>     <pre wrap="">workable? Should a good op-amp be
>     </pre>
>     <blockquote type="cite">
>       <pre wrap="">enought maybe?
> 
> Cheers,
> Magnus
> 
>  
> 
>       </pre>
>     </blockquote>
>   </blockquote>
>   <pre wrap=""><!---->
> 
>   </pre>
> </blockquote>
> </body>
> </html>