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 » Lunettas - circuits inspired by Stanley Lunetta
XOR mixing
Post new topic   Reply to topic Moderators: mosc
Page 1 of 1 [4 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
astroman



Joined: Sep 13, 2012
Posts: 44
Location: UK

PostPosted: Sat Jul 06, 2013 12:05 pm    Post subject: XOR mixing Reply with quote  Mark this post and the followings unread

Really on a roll with my yellow box Lunetta this weekend!
Chanced upon a thing today where I feed an oscillator into pin 1 and the output of a melody generator into pin of a 4070. There was a pot between pins 2 and 3 and the signal to my mixer came out of pin 3. Sounds great! What exactly is happening here?
Back to top
View user's profile Send private message
analog_backlash



Joined: Sep 04, 2012
Posts: 393
Location: Aldershot, UK
Audio files: 21

PostPosted: Sun Jul 07, 2013 4:06 am    Post subject: Reply with quote  Mark this post and the followings unread

Hi astroman.

It sounds like you're getting the pseudo ring modulator effects - see:

http://electro-music.com/forum/viewtopic.php?highlight=4011+ring&t=48145

Here, 4 NAND gates are used, but as is pointed out here, this arrangement of NAND gates gives the same output as a single 4070 (or 4030) XOR gate. I'm not quite sure about the pot between pins 2 and 3. I suppose your feeding the output back into an input, which I haven't tried doing (but it sounds like an interesting idea).

In a true ring modulator, if you feed in two different frequency signals, the output consists of a mix of the sum and the difference of the two frequencies (e.g. 500Hz and 2kHz would give outputs of 2.5kHz and 1.5kHz). These can be mixed with the original inputs, to give a complex sound, which is often like bells, gongs and various metallic objects being hit (especially when you add reverb). The XOR gate produces very similar effects to this, but it's limitation is that it needs square waves to work (it is a logic chip after all). True ring modulators can work with any audio signal inputs.

Gary
Back to top
View user's profile Send private message
JingleJoe



Joined: Nov 10, 2011
Posts: 878
Location: Lancashire, England
Audio files: 14

PostPosted: Mon Jul 15, 2013 12:34 pm    Post subject: Reply with quote  Mark this post and the followings unread

analog_backlash wrote:

It sounds like you're getting the pseudo ring modulator effects

Acctually XOR is real 100% ring modulation, the effect is exactly the same, but only for digital/square waves.

_________________
As a mad scientist I am ruled by the dictum of science: "I could be wrong about this but lets find out"


Green Dungeon Alchemist Laboratories
Back to top
View user's profile Send private message
analog_backlash



Joined: Sep 04, 2012
Posts: 393
Location: Aldershot, UK
Audio files: 21

PostPosted: Mon Jul 15, 2013 3:25 pm    Post subject: Reply with quote  Mark this post and the followings unread

JingleJoe wrote:
analog_backlash wrote:

It sounds like you're getting the pseudo ring modulator effects

Acctually XOR is real 100% ring modulation, the effect is exactly the same, but only for digital/square waves.


Yes, you're dead right JingleJoe. I didn't explain it very well - the "pseudo" was there only because this circuit is limited to square waves. I suppose that you could feed it with any signal that you have "squared up" first e.g. with Tim Escobedo's PWM circuit, or just a hard-driven transistor - I also imagine that this has already been done by somebody Smile .

Gary
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 [4 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


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