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 
 Forum index » DIY Hardware and Software » Lunettas - circuits inspired by Stanley Lunetta
Tuning lunetta?
Post new topic   Reply to topic Moderators: mosc
Page 1 of 1 [2 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
madskill42



Joined: Jun 30, 2011
Posts: 25
Location: czech rep

PostPosted: Thu Jun 30, 2011 6:59 am    Post subject: Tuning lunetta?
Subject description: Is it possible on breadboard?
Reply with quote  Mark this post and the followings unread

Hi there,

I've been building stuff from CMOS for past a week or so, and after APC (which was somehow broken after it was working for like 10 minutes, hehe), I'm building stuff with 40106 chip. It's working quite well, but I have a question about tuning.

I've searched the forum and came across this:
http://www.electronics-tutorials.ws/waveforms/generators.html

and this equation seems to be solution to tuning oscillators. But I might have it wrong, because nothing that came out of this equation is even remotely close to what is measured in spectral analyzer in Ableton.

So it the equation like this?

Frequency = 1 / (1,2 * R * C)

in which R stands for resistance in ohms and C for capacity in farads.

Another thing that bothers me is fact that breadboard is supposed to create some "parasitic" capacity which can cause tuning of breadboarded circuit sound different than mounted on PCB.

And last thing I've noticed. When I connect 10K pot instead or just resistor, and try to tune it to certain frequency, after a while signal starts to "slide" higher or down in pitch very slowly. I don't know why is this happening. Pot was standing still on table.

So, is there some way how to get precise tuned 40106 oscillators?
Back to top
View user's profile Send private message
bubzy



Joined: Oct 27, 2010
Posts: 562
Location: United Kingdom
Audio files: 63

PostPosted: Thu Jun 30, 2011 7:44 am    Post subject: Reply with quote  Mark this post and the followings unread

welcome to electro-music Smile

im no expert on this but afaik, you will need to build a proper vco if you want to be able to "tune" it (and then when its built you will need a control voltage that you can actually 'play' the notes with) you can get rough approximations of the notes you want and probably get them to hold fairly well too by using preset resistor values. (make sure you tie the unused inputs on the 40106 to GND, this is a common problem with weird behaviour)

you will get drift on most things that arent inherently "drift proof" which is why proper VCO's have tempco's and very stable capacitor types.
check this out for a 40106 vco http://electro-music.com/forum/topic-34550.html

here also are some awesomely simple circuits, including a really easy vco (not sure of its tracking, but its so easy its worth a go)
http://electro-music.com/forum/viewtopic.php?highlight=40106+vco&t=28799
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 [2 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