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 » Developers' Corner
One-Shot Circuit 555 or Transistors?
Post new topic   Reply to topic Moderators: DrJustice
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
metal_head_82



Joined: Dec 27, 2009
Posts: 34
Location: Germany
Audio files: 2

PostPosted: Sun Apr 11, 2010 11:29 am    Post subject:  One-Shot Circuit 555 or Transistors? Reply with quote  Mark this post and the followings unread

Hey there!

I'm currently building a simple drum and percussion synth. And now I'm dealing with the envelope generation for pitch sweep and the vca.
The EG should only generate Release. And for that reason I need a monostable multivibrator. So far so good Wink

And now - here's my question:
I'm pretty new to all that electronic stuff and I'm not quiet sure what type of circuit will be better for my little noise machine - a circuit usind a 555 timer or the good old transitor monostable.

I ran some simulations and both work but most simulators use ideal components. I need to know which circuit is more reliable and works best. As far as I know, the 555 circuit has a lower part count and will need less space on a PCB. So could someone please help me out?

Thx in advance.

_________________
"I don't care much about music. What I like is sounds."
Back to top
View user's profile Send private message
JovianPyx



Joined: Nov 20, 2007
Posts: 1988
Location: West Red Spot, Jupiter
Audio files: 224

PostPosted: Sun Apr 11, 2010 12:29 pm    Post subject: Reply with quote  Mark this post and the followings unread

My Opinion:

I doubt that you'll hear a difference in sound between a discrete transistor one shot and an IC type.

That said, the 555 is a bipolar part which crowbars the powersupply for an instant during output switching. This causes a power supply glitch that might affect other circuits powered by the same supply.

Use a 7555 timer instead - these are pin for pin replacements for the 555 timer, but are made from CMOS and do not crowbar the power supply. Any circuit designed for a 555 timer should work properly (better actually) with a 7555 timer.

_________________
FPGA, dsPIC and Fatman Synth Stuff

Time flies like a banana.
Fruit flies when you're having fun.
BTW, Do these genes make my ass look fat?
corruptio optimi pessima
Back to top
View user's profile Send private message Visit poster's website
metal_head_82



Joined: Dec 27, 2009
Posts: 34
Location: Germany
Audio files: 2

PostPosted: Sun Apr 11, 2010 12:41 pm    Post subject: Reply with quote  Mark this post and the followings unread

The impact on sound won't be there. This circuit is just meant to do a short one-shot for about 5ms or so.

Just enough to do the attack for the envelope. After attack it goes straight to release. So that trigger impulse won't be able to effect the sound. But if the 555 messes with my power supply I'd better use a transistor circuit oder a 7555 IC.

But as I don't know when I'll place an order at the electronic store, I'll try a transistor version first.

Thx

_________________
"I don't care much about music. What I like is sounds."
Back to top
View user's profile Send private message
metal_head_82



Joined: Dec 27, 2009
Posts: 34
Location: Germany
Audio files: 2

PostPosted: Tue Apr 20, 2010 3:16 am    Post subject: Reply with quote  Mark this post and the followings unread

Little update:

Placed an order at my preferred tech-dealer and got the parts today. Will try a circuit with the 7555 as soon as my noise generator problem is solved...

Topic here: http://electro-music.com/forum/topic-41286.html

Yeah... Extreme Crossposting Laughing

_________________
"I don't care much about music. What I like is sounds."
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic Moderators: DrJustice
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 » Developers' Corner
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