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
Add VCOs to my CSY-1
Post new topic   Reply to topic Moderators: jksuperstar, Scott Stites, Uncle Krunkus
Page 1 of 1 [3 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
anders79



Joined: Jun 21, 2010
Posts: 21
Location: Sweden

PostPosted: Wed Jun 23, 2010 4:30 am    Post subject: Add VCOs to my CSY-1 Reply with quote  Mark this post and the followings unread

Hello!

I've been watching this forum for a couple of years now and have learnt a lot from here. Since I'm a beginner and very interested in synth-DIY I became a member two days ago.

Ok, I hope this is the right place for questions about my project with my Yamaha CSY-1 monosynth/organ from 1974. It's a wonderful sounding synth, but a little bit thin in its sound, since it contains only a single VCO.
What I would like to do is to add some extra VCOs to it, so I've been searching around for schematics of simple linear VCOs, and this is what I have found on the net and from other discussions here on electro-music:

1: http://www.seekic.com/forum/22_circuit_diagram/19893_LINEAR_VCO.html

2: The linear version of Rene Schmitz 4069 VCO of Scott G.

3: Nicolas super simple V/Hz vco.

4. The square/triangle VCO on the LM13600 datasheet.

5. The LM3900 VCO showed in this thread: http://electro-music.com/forum/ntopic-26808.html

6. Multiple 4046 VCOs (pitch-tracked with the contained PLL) with different vibrato LFOs to get a slightly detuned effect. I know that the bad linearity of 4046 VCO makes it impossible to give them different CVs, the beatings between the VCOs changes too much for every note. So maybe different vibratos for each VCO is better since the phase relationship between the LFOs is always the same?

I want it simple because I want to build more than one.
I want the effect of multiple VCOs, slightly detuned, and of course I want it simple, but with good tracking in at least a couple of octaves. Will anyone of those VCOs I've listed be good enough for that?

The plan is to frequency-track the CSY-1 VCO with a LM2907 and use that voltage to the added VCOs (and fine-tune them) and route those to the filter together with the original VCO.
Any suggestions how it could be done more simple or more effective?

kind regards Anders
Back to top
View user's profile Send private message
Tim Servo



Joined: Jul 16, 2006
Posts: 924
Location: Silicon Valley
Audio files: 11

PostPosted: Thu Jun 24, 2010 2:16 pm    Post subject: Add VCOs to my CSY-1 Reply with quote  Mark this post and the followings unread

Hey Anders,

Instead of adding another VCO to your synth, maybe you could try to get a "thicker" sound by experimenting with some waveshapers. I would think a suboctave (or two) would be a good place to start. You might also look at a Pulse Width Modulation circuit and/or a "wave folder" circuit. These would give you some more sonic possibilities, without the tracking problems of a separate VCO. Of course, you'll want to get the schematics or do some careful exploration with an oscilloscope to see what sort of signal levels are used in that synth. Of course, a second VCO would also be very cool, but the waveshapers might be a simpler place to start. Just a thought.

Tim (thinking, but not too much) Servo
Back to top
View user's profile Send private message
keyman2



Joined: Jul 16, 2013
Posts: 4
Location: Canada

PostPosted: Tue Jul 16, 2013 7:16 pm    Post subject: Re: Add VCOs to my CSY-1 Reply with quote  Mark this post and the followings unread

It's not a bad idea, you can have tracking 5th's, 7th's and octave's, the only thing is they are static but you could add some chorusing effect to liven things up as well.

Tim Servo wrote:
Hey Anders,

Instead of adding another VCO to your synth, maybe you could try to get a "thicker" sound by experimenting with some waveshapers. I would think a suboctave (or two) would be a good place to start. You might also look at a Pulse Width Modulation circuit and/or a "wave folder" circuit. These would give you some more sonic possibilities, without the tracking problems of a separate VCO. Of course, you'll want to get the schematics or do some careful exploration with an oscilloscope to see what sort of signal levels are used in that synth. Of course, a second VCO would also be very cool, but the waveshapers might be a simpler place to start. Just a thought.

Tim (thinking, but not too much) Servo
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic Moderators: jksuperstar, Scott Stites, Uncle Krunkus
Page 1 of 1 [3 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
AmbiphonicDSP

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