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
Silence oscillation
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
squarewhite



Joined: Jun 06, 2007
Posts: 62
Location: Asia

PostPosted: Mon Dec 03, 2012 3:21 am    Post subject: Silence oscillation Reply with quote  Mark this post and the followings unread

Hi

I've built from nicolas collins book a diy vactrol panner. I'm using the 40106 as the panner. There are different caps which creates different speed. I've hook up the panner as in the book. My problem is that there is always a sound coming from the panner, 40106 oscillating. How can i silence this oscillation? It's annoying when i send a sound into it and there is this constant sound. Any advice on this?
Back to top
View user's profile Send private message
Psyingo



Joined: Jun 11, 2009
Posts: 247
Location: Canada

PostPosted: Mon Dec 03, 2012 10:51 am    Post subject: Reply with quote  Mark this post and the followings unread

have you added any decoupling caps? 100nF on the +v pin of the chip to gnd, as close as possible, with as short of leads as possible. and a big cap, say 100uF or more from + to gnd.

also how close is the vactrol to the 40106? is it on a breadboard? if its close, try moving it further away?

and then after that, is there any DC offset present in the signal you are panning? even if the signal is silent there could still be, say, 0.5v or something of offset, and with that your oscillator may leak through because it is turning on and off that offset to impose itself... try putting a 1uF cap before the vactrol if there isnt one already.
Back to top
View user's profile Send private message Visit poster's website MSN Messenger
squarewhite



Joined: Jun 06, 2007
Posts: 62
Location: Asia

PostPosted: Mon Dec 03, 2012 5:45 pm    Post subject: Reply with quote  Mark this post and the followings unread

thanks for the tip. No I didn't add any decoupling caps. I'll do the modification once I get back home.

no I've already build in on the pcb. you can see it in the pic, left corner. The vactrols are left and right of the 40106. (on the left side of the pic)

how do I check for DC offset? I don't have a oscilloscope. Do you mean putting a 1uF cap before signal in and vactrol? I'm using 1 mono input to the vactrols; input-vactrol1-vactrol2.

Last edited by squarewhite on Mon Dec 03, 2012 7:07 pm; edited 1 time in total
Back to top
View user's profile Send private message
Psyingo



Joined: Jun 11, 2009
Posts: 247
Location: Canada

PostPosted: Mon Dec 03, 2012 6:06 pm    Post subject: Reply with quote  Mark this post and the followings unread

What picture are you referring to? I dont see a picture posted here
Back to top
View user's profile Send private message Visit poster's website MSN Messenger
squarewhite



Joined: Jun 06, 2007
Posts: 62
Location: Asia

PostPosted: Mon Dec 03, 2012 6:32 pm    Post subject: Reply with quote  Mark this post and the followings unread

oops.. here you go.


CigarNoBo7.JPG
 Description:
 Filesize:  638.77 KB
 Viewed:  51 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

CigarNoBo7.JPG


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
emSynth

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