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
Gate or Trigger Levels
Post new topic   Reply to topic Moderators: jksuperstar, Scott Stites, Uncle Krunkus
Page 1 of 1 [6 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
fonik



Joined: Jun 07, 2006
Posts: 3760
Location: Germany
Audio files: 23

PostPosted: Fri Feb 08, 2013 4:20 am    Post subject: Gate or Trigger Levels
Subject description: Why limit these?
Reply with quote  Mark this post and the followings unread

every now and then i read here about gate and trigger levels and their standardization.

my point of view:
don't care to limit the level of the gate or trigger, but the threshold of the input! it is the input that has to be defined. for the output i would go for the highest voltage possible to be sure to be able to trigger anything.

i am currently working on the thomas henry CMOS ADSR and i will add stage gates and an end trigger. i see no reason to limit these, i will just let the opamps (comparators) swing to their limits (roughly 10V for a TL072 powered by 12V).

why would one limit the gate/trigger outputs to i.e. 5V?

_________________
Posted Image, might have been reduced in size. Click Image to view fullscreen.
cheers,
matthias
____________
fonitronik at
FlickR (pix) / SoundCloud (sounds) / YouTube (vids) / Vimeo (vids) / facebook (news)
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Paradigm X



Joined: Feb 15, 2011
Posts: 286
Location: Null and void

PostPosted: Fri Feb 08, 2013 7:16 am    Post subject: Reply with quote  Mark this post and the followings unread

Matthias

I cant offer any assistance, noob as you know, but I too find this really confusing. There are a number of projects where you have to decide early (klee/dave's midi2clock).

My best guess at this stage is to make as high as possible, so they can be more easily attenuated. So on that basis i think I agree with your assumption to leave high.

I obviously would also be interested to hear what others think.

Regards
Ben
Back to top
View user's profile Send private message
PHOBoS



Joined: Jan 14, 2010
Posts: 1853
Location: Moon Base
Audio files: 361

PostPosted: Fri Feb 08, 2013 8:04 am    Post subject: Reply with quote  Mark this post and the followings unread

well for analog levels I use -5V...+5V so for me it makes perfect sense to have triggers/gates at 0/+5V. This also has the advantage that
you can use it directly with digital circuits that use a PIC/arduino and run on 5V.

_________________
"My perf, it's full of holes!"
http://phobos.000space.com/ http://www.acidtrash.com/ Stickney Synthyards
Back to top
View user's profile Send private message Visit poster's website AIM Address Yahoo Messenger MSN Messenger
corex



Joined: Mar 02, 2010
Posts: 114
Location: Las Vegas

PostPosted: Fri Feb 08, 2013 2:43 pm    Post subject: Reply with quote  Mark this post and the followings unread

I can't think of a good reason within a modular, but perhaps if interfacing with external devices then a 5V gate would be useful.
Back to top
View user's profile Send private message
Thomas_Henry



Joined: Jul 24, 2009
Posts: 129
Location: N. Mankato, MN

PostPosted: Fri Feb 08, 2013 4:33 pm    Post subject: Reply with quote  Mark this post and the followings unread

Hello Fonik,

If you decide to go that route, then I suggest you provide pads for the voltage divider on the outputs anyway. If a person wants standard synth levels, then he or she can pop in the two resistors (3k and 1.5k, which gives a +5V output and 1k impedance). If they don't want this, then the 1.5k is left out and the 3k is replaced either with a jumper (0 output Z) or a 1k resistor (1k output Z).

Also, I hope you will make the staging outputs completely optional, as per my original design. A person can just leave out the quad op-amp (assuming that's what you're using) and associated components if staging is not desired.

Thomas Henry
Back to top
View user's profile Send private message
JRock



Joined: Mar 05, 2010
Posts: 80
Location: Bucks County, PA
Audio files: 1

PostPosted: Thu Feb 14, 2013 11:59 pm    Post subject: Reply with quote  Mark this post and the followings unread

Hey. Glad I was cruising through on a late night Cool

I have a cabinet filled with a bunch of CMOS logic that I didn't chop down the output on (Outputting ~11V to 13V). I felt the same way. Nothing's more frustrating than not being able to trigger your trigger input because the signal's too weak.

It's caused me some problems though. Current Draw on my system is one. LEDs, Gates, Triggers, you get a bunch of them all going at the same time and it get's taxing on the PSU.

It's caused me problems on envelopes too. They're expecting 5 or 7V. If you send 16th notes at 160 BPM or higher and the Gates and Triggers aren't knocked down a little bit from 13V the EG starts missing notes (it just stays on).

I agree that the threshold should be defined by the inputs. It might be easier if the standard was an 8 to 10V trigger because you wouldn't have to add a pair of transistors at the input to boost the gate level to work with CMOS powered by 12 or 15V.
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 [6 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
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