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
  EdisonRex Edison's Electronic Review
Please visit the chat
 Forum index » DIY Hardware and Software » Thomas Henry designs
few questions about the cmos-adsr
Post new topic   Reply to topic Moderators: Scott Stites
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
smallstone



Joined: Mar 24, 2014
Posts: 2
Location: Germany

PostPosted: Mon Mar 24, 2014 5:30 am    Post subject: few questions about the cmos-adsr Reply with quote  Mark this post and the followings unread

hey guys,

sorry but my english ist not so well because iam from Germany.

In the moment i build the 8038 oscillator from Thomas Henry, i want controll the pitch via a keyboard with controll voltage.
Tomorow came the next components (resistors, capacitors) for the 8038 VCO. Then i finish the VCO.

After that i want build the ADSR from Thomas Henry, but i dont understand wehre i must connect the "gate" and the "trigger" on my 8038 VCO or keyboard.

Could you help me please ?


Thanks for your help, i hope you understand me Wink
Back to top
View user's profile Send private message
elmegil



Joined: Mar 20, 2012
Posts: 1519
Location: Chicago
Audio files: 14

PostPosted: Mon Mar 24, 2014 8:18 pm    Post subject: Reply with quote  Mark this post and the followings unread

If I understand correctly what you want to do, you will need a VCA as well. The one in Analog Synth for the 21st Century is pretty straightforward; I've built it as written (VCA + VCF) and also as a dual VCA (duplicate the core circuit for both halves of the V2164 chip).

the "traditional" arrangement is

keyboard CV -> VCO V/Oct
VCO out -> VCA audio in
Keyboard gate + trigger -> ADSR gate + trigger in
ADSR out -> VCA control in
VCA out == your "notes" with the envelope specified by the ADSR.

I googled for images but found very little. If you get Analog Synth for the 21st Century from Lulu it has a diagram at the end which includes these parts and many others.
Back to top
View user's profile Send private message
smallstone



Joined: Mar 24, 2014
Posts: 2
Location: Germany

PostPosted: Tue Mar 25, 2014 11:41 am    Post subject: Reply with quote  Mark this post and the followings unread

Yes, you understand me correctly.

But i have one more questions.

Is "gate" = Control Voltage ?


Thanks for your patience !
Back to top
View user's profile Send private message
elmegil



Joined: Mar 20, 2012
Posts: 1519
Location: Chicago
Audio files: 14

PostPosted: Tue Mar 25, 2014 12:23 pm    Post subject: Reply with quote  Mark this post and the followings unread

No, a keyboard (or a MIDI2CV interface) will generally create three signals

1) CV is a voltage corresponding to the pitch of the key.

2) Trigger is a pulse corresponding to the initial press of the key.

3) Gate is a signal that is high while the key is pressed and low when it is released.

Many ADSRs will recognize gate, or trigger, or both. The advantage of both is it lets you do things like legato playing where the gate stays high the whole time but the envelope re-triggers on each key press.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic Moderators: Scott Stites
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 » Thomas Henry designs
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