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

poster

Please visit the chat
 Forum index » DIY Hardware and Software » YuSynth
ADSR V2 - LED constantly lit
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
hububalli



Joined: Feb 15, 2014
Posts: 17
Location: UK

PostPosted: Sat Apr 07, 2018 6:40 am    Post subject: ADSR V2 - LED constantly lit Reply with quote  Mark this post and the followings unread

So on to the next module! The module appears works fine but there is a constant 2.5v at pin 7 of U2, the TL074, so the LED is constantly partially illuminated. When the gate is triggered the LED does respond as expected.

There is a constant +- 100 mV at the outputs when the gate is not triggered if that is of any use. When you manually trigger, you can see the ADSR stages on the outputs on the scope fine.

Any suggestions as to what I should check? Thanks,
Back to top
View user's profile Send private message
g.gabba



Joined: Nov 29, 2008
Posts: 390
Location: berlin
Audio files: 23

PostPosted: Sat Apr 07, 2018 12:00 pm    Post subject: Reply with quote  Mark this post and the followings unread

hey you,
please post always a direct link to the schematic you are talking about
i guess it is that?:
http://yusynth.net/Modular/Commun/ADSR/ADSR-V2-sch.gif

are u are shure u are measuring positive 2,5V at pin 7 of U2? or negative?

can you disconnect R22 at pin 6 of U2b and connect one channel of ur scope there at R22
second channel at pin3 of te 555 (gate)
and post a photo of that two signals?

to the 100mV we could say it is noise

cu tomorrow
Back to top
View user's profile Send private message
hububalli



Joined: Feb 15, 2014
Posts: 17
Location: UK

PostPosted: Sun Apr 08, 2018 8:32 am    Post subject: Reply with quote  Mark this post and the followings unread

Hello again g.gabba,

This is the schematic I used, which matches the PCB.

http://yusynth.net/Modular/Commun/ADSR/ADSR555-FINAL.gif

You are right, it is -2.5 V.

I disconnected R18 at pin6 of U2b and connected my scope to the free end of R18, is that what you wanted?

Posted Image, might have been reduced in size. Click Image to view fullscreen.

Thanks for the help,
Back to top
View user's profile Send private message
g.gabba



Joined: Nov 29, 2008
Posts: 390
Location: berlin
Audio files: 23

PostPosted: Sun Apr 08, 2018 10:43 am    Post subject: Reply with quote  Mark this post and the followings unread

yesssss, this is how we work,

now we know that your circuit is working well (as far as i can see imo)
up to the end of R18.

Now connect Pin6 to GND.

then measure
Pin 5,6 and 7 also with the scope, in case there is some weird noise.
please measure on the pins of the IC not on the solderpoints,

cu Smile
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 » YuSynth
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