electro-music.com   Dedicated to experimental electro-acoustic
and electronic music
 
    Front Page  |  Radio
 |  Media  |  Forum  |  Wiki  |  Links
Forum with support of Syndicator RSS
 FAQFAQ   CalendarCalendar   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   LinksLinks
 RegisterRegister   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in  Chat RoomChat Room 
 Forum index » DIY Hardware and Software
Phase Shifters
Post new topic   Reply to topic Moderators: jksuperstar, Scott Stites, Uncle Krunkus
Page 1 of 1 [9 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
synthmonger



Joined: Nov 16, 2006
Posts: 578
Location: flada
Audio files: 3

PostPosted: Tue Jun 16, 2009 3:23 am    Post subject: Phase Shifters
Subject description: Some questions
Reply with quote  Mark this post and the followings unread

I haven't seen any designs for modular phasers out there so I've decided to take it upon myself to build one from scratch using only the textbook phase cells.

Instead of transistors or vactrols I've decided to use something way out of the ordinary -my VCOVR's. The results have been very pleasing and interesting. A lot of questions came to mind when I was getting similar results between feedback control and adjusting the bias.

Is self oscillation possible with all filters?

Is there a difference between 'feedback' and 'resonance'?

Is center frequency the same as cut off frequency?

I've read anything above 12 stages isn't really worth it. Yet I've heard Scott Stites 32 phase Multi-phase samples and totally loved the sound. What do you guys think?

I have no experience with the Doepfer Vactrol phaser nor have I seen any demos. Is it really worth adding all the feedback inputs?

I'll try posting some audio clips of what I have so far in the next couple of days. Super busy this week! Crying or Very sad Crying or Very sad Crying or Very sad

_________________
Youtube!
modular demos!
Whacky tunes!
Back to top
View user's profile Send private message Visit poster's website
RF



Joined: Mar 23, 2007
Posts: 1502
Location: Northern Minnesota, USA
Audio files: 28

PostPosted: Tue Jun 16, 2009 4:50 am    Post subject: Reply with quote  Mark this post and the followings unread

MFOS has an 8-stage phase shifter...

http://www.musicfromouterspace.com/analogsynth/PHASESHIFTER2007/PHASESHIFTER2007.php

I'll be interested in hearing and seeing what you come up with!

bruce

_________________
www.sdiy.org/rfeng

"I want to make these sounds that go wooo-wooo-ah-woo-woo.”
(Herb Deutsch to Bob Moog ~1963)
Back to top
View user's profile Send private message
synthmonger



Joined: Nov 16, 2006
Posts: 578
Location: flada
Audio files: 3

PostPosted: Tue Jun 16, 2009 5:13 am    Post subject: Reply with quote  Mark this post and the followings unread

RF wrote:
MFOS has an 8-stage phase shifter...

http://www.musicfromouterspace.com/analogsynth/PHASESHIFTER2007/PHASESHIFTER2007.php

I'll be interested in hearing and seeing what you come up with!

bruce


Oh forgot about that one. I did check that one out. Any others? ;d

_________________
Youtube!
modular demos!
Whacky tunes!
Back to top
View user's profile Send private message Visit poster's website
fonik



Joined: Jun 07, 2006
Posts: 3950
Location: Germany
Audio files: 23

PostPosted: Tue Jun 16, 2009 5:37 am    Post subject: Reply with quote  Mark this post and the followings unread

thomas henry's phase shifter from the 21th century synthesizer, LM13700 based.

maybe we could get magic smoke to be this project their next PCB!?

_________________
Posted Image, might have been reduced in size. Click Image to view fullscreen.
cheers,
matthias
____________
Big Boss at fonitronik
Tech Buddy at Random*Source
Back to top
View user's profile Send private message Send e-mail Visit poster's website
synthmonger



Joined: Nov 16, 2006
Posts: 578
Location: flada
Audio files: 3

PostPosted: Tue Jun 16, 2009 6:20 pm    Post subject: Reply with quote  Mark this post and the followings unread

Here's a quick audio clip of mine.

Direct to soundcard and no digital effects other than fade ins and shortening it.

The audio input is a pulse wave whose width is controlled manually but only a little. There is a triangle LFO controlling the phase frequency moving at a slow speed in the begining then I tune it to the same frequency as the input frequency. Listen for some very smooth sounding bass at :29 and later at 1:40ish.

I also adjust the LFO modulation knob from all to nothing a couple times as well as the resonance and drive knob.

This is all done with a 4 stage module. I think the final module will have 8 stages and include VC drive, VC modulation frequency, VC frequency, VC modulation resonance, VC resonance, individual stage outputs and I'm contemplating weather or not of having individual stage inputs. I wouldn't want to copy Doepfers design but it seems almost too silly to pass it up with individual outputs. Whatcha guys think?


early_phase_shift_demo.mp3
 Description:

Download
 Filename:  early_phase_shift_demo.mp3
 Filesize:  2.22 MB
 Downloaded:  1120 Time(s)


_________________
Youtube!
modular demos!
Whacky tunes!
Back to top
View user's profile Send private message Visit poster's website
Sebo



Joined: Apr 27, 2007
Posts: 564
Location: Argentina

PostPosted: Tue Jun 16, 2009 7:14 pm    Post subject: Reply with quote  Mark this post and the followings unread

Here is another one:
http://hem.bredband.net/bersyn/vcp.htm

_________________
Sebo
---------------------------------------
My Music:
https://www.facebook.com/cosaquitos/
Back to top
View user's profile Send private message
toppobrillo



Joined: Dec 10, 2005
Posts: 766
Location: oakland, ca
G2 patch files: 1

PostPosted: Tue Jun 16, 2009 7:41 pm    Post subject: Reply with quote  Mark this post and the followings unread

jurgen is releasing an interesting project: http://electro-music.com/forum/topic-32897.html

and of course there was a Tau PCB as well, but these are quite a bit more advanced ideas...

FWIW, personally I think that all the individual stage outputs would be overkill and wouldn't serve much purpose in application.
Back to top
View user's profile Send private message Visit poster's website
synthmonger



Joined: Nov 16, 2006
Posts: 578
Location: flada
Audio files: 3

PostPosted: Tue Jun 16, 2009 7:57 pm    Post subject: Reply with quote  Mark this post and the followings unread

topp wrote:


FWIW, personally I think that all the individual stage outputs would be overkill and wouldn't serve much purpose in application.


I can see inputs being overkill but individual phase outputs seem useful to me for CV applications in self-oscillating mode.

_________________
Youtube!
modular demos!
Whacky tunes!
Back to top
View user's profile Send private message Visit poster's website
synthmonger



Joined: Nov 16, 2006
Posts: 578
Location: flada
Audio files: 3

PostPosted: Wed Jun 17, 2009 3:59 am    Post subject: Reply with quote  Mark this post and the followings unread

synthmonger wrote:
topp wrote:


FWIW, personally I think that all the individual stage outputs would be overkill and wouldn't serve much purpose in application.


I can see inputs being overkill but individual phase outputs seem useful to me for CV applications in self-oscillating mode.



NM self oscillate mode doesn't mean each output will be oscillating at the same level.

EDIT: had one thing wired wrong causing the levels to be whacky. Now I might make individual ouputs! ;d


That about covers it. PCB this weekend maybe!

_________________
Youtube!
modular demos!
Whacky tunes!
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic Moderators: jksuperstar, Scott Stites, Uncle Krunkus
Page 1 of 1 [9 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
 Forum index » DIY Hardware and Software
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Forum with support of Syndicator RSS
Powered by phpBB © 2001, 2005 phpBB Group
Copyright © 2003 through 2009 by electro-music.com - Conditions Of Use