electro-music.com   Dedicated to experimental electro-acoustic
and electronic music
 
    Front Page  |  Articles  |  Radio
 |  Media  |  Forum  |  Wiki  |  Links  |  Store
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 
Live streaming at radio.electro-music.com

  host / artist show at your time
  Faux Pas Quartet and friends Music From Last Thursday
Please visit the chat
 Forum index » DIY Hardware and Software » Lunettas - circuits inspired by Stanley Lunetta
VCF for Workshop Synth
Post new topic   Reply to topic Moderators: mosc
Page 1 of 1 [5 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
kaputtpanzer



Joined: Nov 02, 2009
Posts: 62
Location: Cologne
Audio files: 2

PostPosted: Thu May 29, 2014 11:47 am    Post subject: VCF for Workshop Synth Reply with quote  Mark this post and the followings unread

Hello friends,

lately I am working on a "everything-on-one-pcb" synth, for a workshop I will give for some fellow students.

I decided to make a very simple tone generator, 2 Schmitt Trigger OSCs feed their signals into a NAND gate (pseudo ringmod Rolling Eyes ). In additional the synth will have a simple LFO to control the VCF.

I breadboarded some filters. Including the Ruin CMOS VCF (http://www.electro-music.com/forum/topic-55851.html) and the q&d VCF (http://www.jiggawoo.eclipse.co.uk/guitarhq/Circuitsnippets/simplevcf.gif).

But both of them were unsuitable for my project. The CMOS VCF has a too small filter range (I changed a lot of components to make it more suitable, but it is still not so good) and the Q&D VCF starts to hum when my hand was getting closer to the op-amp. If I would use a enclosure that would be not an issue, but for this project it wont work.

I am looking for a VCF that is suitable for this pcb trim-pot synth. I breadboarded the MS-20 9V VCF a few years ago and was really impressed by it. So I think I will use something like this. Are there some other easy to build LM 13600/700 OTA VCFs? And will it hum when my hand is getting close to the IC?

The image shows a early version of the pcb layout...


WS.png
 Description:
WS synth
 Filesize:  36.87 KB
 Viewed:  25 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

WS.png


Back to top
View user's profile Send private message
DUBmatze



Joined: Feb 18, 2013
Posts: 111
Location: south Germaica (schwabilon)

PostPosted: Fri May 30, 2014 1:25 am    Post subject: Reply with quote  Mark this post and the followings unread

i like this filter:
http://electro-music.com/forum/topic-45231.html

_________________
http://matze.reggaestriert.de/diy-projekte/
Back to top
View user's profile Send private message Visit poster's website
kaputtpanzer



Joined: Nov 02, 2009
Posts: 62
Location: Cologne
Audio files: 2

PostPosted: Fri May 30, 2014 2:53 am    Post subject: Reply with quote  Mark this post and the followings unread

Hey Matze (again Very Happy ),

the Problem with all the op amp filter things is the humming (when I get near the IC with my hand). I "made" a lp/hp-filter two years ago and planned to use it, but I can't because of the humming, caused by electro magnetic fields or something esoteric. Razz

Posted Image, might have been reduced in size. Click Image to view fullscreen.

But this filter sounds actually exact like I wanted to sound for the workshop synth.

http://electro-music.com/forum/phpbb-files/9v_filter_107.mp3

[/img]
Back to top
View user's profile Send private message
DUBmatze



Joined: Feb 18, 2013
Posts: 111
Location: south Germaica (schwabilon)

PostPosted: Sat May 31, 2014 10:26 am    Post subject: Reply with quote  Mark this post and the followings unread

kaputtpanzer wrote:
but I can't because of the humming, caused by electro magnetic fields or something esoteric. Razz
Posted Image, might have been reduced in size. Click Image to view fullscreen.
maybe some simple shilding help...
Shocked

_________________
http://matze.reggaestriert.de/diy-projekte/
Back to top
View user's profile Send private message Visit poster's website
kaputtpanzer



Joined: Nov 02, 2009
Posts: 62
Location: Cologne
Audio files: 2

PostPosted: Sat May 31, 2014 10:44 am    Post subject: Reply with quote  Mark this post and the followings unread

Haha! This would help, I guess. Maybe after they finished their pcb, the can wrap it in "Alufolie"... Cool
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic Moderators: mosc
Page 1 of 1 [5 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 » Lunettas - circuits inspired by Stanley Lunetta
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
e-m mkii

Please support our site. If you click through and buy from
our affiliate partners, we earn a small commission.


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