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 » YuSynth
Ring Mod Help
Post new topic   Reply to topic Moderators: Scott Stites
Page 1 of 2 [28 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Goto page: 1, 2 Next
Author Message
Snaper



Joined: Feb 28, 2014
Posts: 217
Location: Hungary

PostPosted: Fri Jan 23, 2015 10:25 am    Post subject: Ring Mod Help Reply with quote  Mark this post and the followings unread

Hi Guys,

Just finished the Balanced Ring mod, for my Euro system.
Its powered from +/12V, and just to know, basically cutted the PCB in half, cause I didn't need a dual version. (Every trace is in place.)

My problem is that the out is tooooooo low.
I mean, I have to amplify it to hear something :S

Used MC1496, instead of LM.

Did anyone experienced the same problem?

What should I check first?
Back to top
View user's profile Send private message
Snaper



Joined: Feb 28, 2014
Posts: 217
Location: Hungary

PostPosted: Fri Jan 23, 2015 11:42 am    Post subject: Reply with quote  Mark this post and the followings unread

Measured a few things...weird :S

Nothing plugged in :

AC ins/outs : 0 V
DC in : there are voltages :O !!!! (-2,7v on Input B and +6,75v on Input A)
DC out : -10,32v

Something is wrong :S
Back to top
View user's profile Send private message
Snaper



Joined: Feb 28, 2014
Posts: 217
Location: Hungary

PostPosted: Sat Jan 24, 2015 12:06 am    Post subject: Reply with quote  Mark this post and the followings unread

Totally disconnected the DC inputs, and outputs, now, no sound, nothing :S
Nothing, even if fiddle with trimpots.
Should I drop the board to the trash or is it possible to fix this?
Back to top
View user's profile Send private message
yusynth



Joined: Nov 24, 2005
Posts: 1314
Location: France

PostPosted: Sat Jan 24, 2015 4:08 am    Post subject: Reply with quote  Mark this post and the followings unread

What do you input in the module ?
_________________
Yves
Back to top
View user's profile Send private message Visit poster's website
yusynth



Joined: Nov 24, 2005
Posts: 1314
Location: France

PostPosted: Sat Jan 24, 2015 4:12 am    Post subject: Reply with quote  Mark this post and the followings unread

Snaper wrote:
AC ins/outs : 0 V
DC in : there are voltages :O !!!! (-2,7v on Input B and +6,75v on Input A)

This is quite normal
Snaper wrote:
DC out : -10,32v

This is not normal.

_________________
Yves
Back to top
View user's profile Send private message Visit poster's website
Snaper



Joined: Feb 28, 2014
Posts: 217
Location: Hungary

PostPosted: Sat Jan 24, 2015 5:08 am    Post subject: Reply with quote  Mark this post and the followings unread

yusynth wrote:
What do you input in the module ?

Your fantastic VCO Very Happy
(Also from 12v)
Back to top
View user's profile Send private message
Snaper



Joined: Feb 28, 2014
Posts: 217
Location: Hungary

PostPosted: Sat Jan 24, 2015 5:09 am    Post subject: Reply with quote  Mark this post and the followings unread

yusynth wrote:

Snaper wrote:
DC out : -10,32v

This is not normal.

Thats my problem to.
Should I measure all pins of the opamp?
I think there is some kind of problem with the buffer stage.
Tried it several TL072s...
Pin voltages would help you to track down the problem?
Back to top
View user's profile Send private message
yusynth



Joined: Nov 24, 2005
Posts: 1314
Location: France

PostPosted: Sat Jan 24, 2015 5:17 am    Post subject: Reply with quote  Mark this post and the followings unread

Do you use two VCO as sources ? one for each input ? Have you an oscilloscope ? Did you follow the trimming instructions ?
_________________
Yves
Back to top
View user's profile Send private message Visit poster's website
Snaper



Joined: Feb 28, 2014
Posts: 217
Location: Hungary

PostPosted: Sat Jan 24, 2015 6:37 am    Post subject: Reply with quote  Mark this post and the followings unread

yusynth wrote:
Do you use two VCO as sources ?


Yes. Love them!

yusynth wrote:
one for each input ?


Yes.

yusynth wrote:
Have you an oscilloscope ?


Unfortunately, no...

yusynth wrote:
Did you follow the trimming instructions ?


Yapp.

My voltages : (nothing plugged in)

TL072

pin 1 : -9,59
pin 2 : 0
pin 3 : 7,78
pin 4 : -12
pin 5: 0
pin 6 : -10,16
pin 7 : -10,33
pin 8 : 12

MC1496

pin 1 : -3,25
pin 2 : -3,98
pin 3 : -3,98
pin 4 : -3,26
pin 5 : -10,09
pin 6 : 9,87
pin 7 : 0
pin 8 : 7,36
pin 9 : 0
pin 10 : 7,36
pin 11 : 0
pin 12 : 9,94
pin 13 : 0
pin 14 : -12
Back to top
View user's profile Send private message
Snaper



Joined: Feb 28, 2014
Posts: 217
Location: Hungary

PostPosted: Sat Jan 24, 2015 8:27 am    Post subject: Reply with quote  Mark this post and the followings unread

A good friend suggested me a test.
I've "audio checked" the pins of the TL072. (with a jack plug)

I can hear the signal in inputs, and I can hear it on Pin 1. That means, that the problem is with the second opamp stage.
I don't know what could be, cause the resistors are OK.
Back to top
View user's profile Send private message
yusynth



Joined: Nov 24, 2005
Posts: 1314
Location: France

PostPosted: Sat Jan 24, 2015 8:47 am    Post subject: Reply with quote  Mark this post and the followings unread

Considering that you measure 9.87V on pin 6 of the MC1496 and 9.94V on pin 12 (which seems normal), the values that you measure on pins 2 and 3 and consequently 1 of the TL072 are not what is expected.
What one would expect to read is :
pin 2 : 4.97V
pin 3 : 4.97V
pin 1 : 0.070V
as a matter of fact on pin 1 of the TL072 we must read the difference between the voltages at pins 12 and 6 of the MC1496: 9.94V-9.87V that is 0.070V.

Either the TL072 is dead or there is some kind of shortcut on pin 3 or 4 of the TL072...

_________________
Yves
Back to top
View user's profile Send private message Visit poster's website
Snaper



Joined: Feb 28, 2014
Posts: 217
Location: Hungary

PostPosted: Sat Jan 24, 2015 10:38 am    Post subject: Reply with quote  Mark this post and the followings unread

I've re-heated the joints, checked for shorts, etc.
Now its "kinda' " working, there is audible sound, but still extremly low, and I still have the -10.3v at the outs.

The problem is with the second opamp stage, cause I can measure around 5 volts on pin 1 of the TL074, and around 3v on pin 6, but on pin seven, there is -10 :S

Weird...
Back to top
View user's profile Send private message
yusynth



Joined: Nov 24, 2005
Posts: 1314
Location: France

PostPosted: Sat Jan 24, 2015 10:43 am    Post subject: Reply with quote  Mark this post and the followings unread

5V on pin 1 is much too high!
Did you check and change the TL072

_________________
Yves
Back to top
View user's profile Send private message Visit poster's website
Snaper



Joined: Feb 28, 2014
Posts: 217
Location: Hungary

PostPosted: Sat Jan 24, 2015 10:53 am    Post subject: Reply with quote  Mark this post and the followings unread

yusynth wrote:
5V on pin 1 is much too high!
Did you check and change the TL072

5,25 precisely.
Tried 4 diff TLs, its the same...
Back to top
View user's profile Send private message
wackelpeter



Joined: May 05, 2013
Posts: 461
Location: germany
Audio files: 10

PostPosted: Sat Jan 24, 2015 11:01 am    Post subject: Re: Ring Mod Help Reply with quote  Mark this post and the followings unread

Snaper wrote:
Hi Guys,

Just finished the Balanced Ring mod, for my Euro system.
Its powered from +/12V, and just to know, basically cutted the PCB in half, cause I didn't need a dual version. (Every trace is in place.)

My problem is that the out is tooooooo low.
I mean, I have to amplify it to hear something :S

Used MC1496, instead of LM.

Did anyone experienced the same problem?

What should I check first?


seems like you didn't used the original PCB... correct? if this is a stripboard design or your own design... maybe it's a good idea to post some pics of both sides of the PCB... maybe a few more eyes looking at it can find the suspect...
...you know "can't see the wood for the trees" Wink

_________________
https://soundcloud.com/bastian-j
Back to top
View user's profile Send private message
Snaper



Joined: Feb 28, 2014
Posts: 217
Location: Hungary

PostPosted: Sat Jan 24, 2015 11:08 am    Post subject: Re: Ring Mod Help Reply with quote  Mark this post and the followings unread

wackelpeter wrote:
Snaper wrote:
Hi Guys,

Just finished the Balanced Ring mod, for my Euro system.
Its powered from +/12V, and just to know, basically cutted the PCB in half, cause I didn't need a dual version. (Every trace is in place.)

My problem is that the out is tooooooo low.
I mean, I have to amplify it to hear something :S

Used MC1496, instead of LM.

Did anyone experienced the same problem?

What should I check first?


seems like you didn't used the original PCB... correct? if this is a stripboard design or your own design... maybe it's a good idea to post some pics of both sides of the PCB... maybe a few more eyes looking at it can find the suspect...
...you know "can't see the wood for the trees" Wink

Its the PCB from Yves, but just half of it...

In the other hands, I like sharing photos Very Happy

HIRES :

https://www.dropbox.com/sh/nkro4gt3j1ph8x6/AAA1gTKnCnJNTTygEAUEx_yia?dl=0
Back to top
View user's profile Send private message
wackelpeter



Joined: May 05, 2013
Posts: 461
Location: germany
Audio files: 10

PostPosted: Sat Jan 24, 2015 11:34 am    Post subject: Reply with quote  Mark this post and the followings unread

is this a slight short between pin 3 and 4 of your tl072?

what do you measure on pin 2 and 3 of the tl072 right know?
first with chip installed and then without?

_________________
https://soundcloud.com/bastian-j
Back to top
View user's profile Send private message
yusynth



Joined: Nov 24, 2005
Posts: 1314
Location: France

PostPosted: Sat Jan 24, 2015 11:48 am    Post subject: Reply with quote  Mark this post and the followings unread

Once again can you measure the voltage on pin 6 and 12 of the MC1496.
_________________
Yves
Back to top
View user's profile Send private message Visit poster's website
wackelpeter



Joined: May 05, 2013
Posts: 461
Location: germany
Audio files: 10

PostPosted: Sat Jan 24, 2015 11:54 am    Post subject: Reply with quote  Mark this post and the followings unread

and btw is R11 an 15k resistor looks different to R19 to R21... ? i'm not good at reading those colour codes...

edit: could it be that this is a 15k resistor and R19 to R21 aren't...

checking with the 1k5 or 15K resistors in my box they start with brown for 1 and then green for 5 then followed by the code for multiplication and tolerance... don't know if there are different colour codes usual...

your's beginning with green and then brown look like they are something with 51... could be possible that i'm totally wrong

_________________
https://soundcloud.com/bastian-j
Back to top
View user's profile Send private message
Snaper



Joined: Feb 28, 2014
Posts: 217
Location: Hungary

PostPosted: Sat Jan 24, 2015 12:31 pm    Post subject: Reply with quote  Mark this post and the followings unread

yusynth wrote:
Once again can you measure the voltage on pin 6 and 12 of the MC1496.

pin 6 : 9,97
pin 12 : 9,84
Back to top
View user's profile Send private message
yusynth



Joined: Nov 24, 2005
Posts: 1314
Location: France

PostPosted: Sat Jan 24, 2015 12:38 pm    Post subject: Reply with quote  Mark this post and the followings unread

You should have 0.070 at pin 1 of the TL072 check thoroughly all the components connected to pins 1,2 and 3 of the TL074, check for a short between tracks. Remove TL072 and repeat the measures at pin 1,2 and 3 of the TL072
_________________
Yves
Back to top
View user's profile Send private message Visit poster's website
Snaper



Joined: Feb 28, 2014
Posts: 217
Location: Hungary

PostPosted: Sat Jan 24, 2015 12:50 pm    Post subject: Reply with quote  Mark this post and the followings unread

Embarassed Embarassed Embarassed Embarassed Embarassed Embarassed Embarassed Embarassed Embarassed Embarassed

OUCH!
What a n0000b failure!

Those 15k resistors...are...51k ones...
I think I have "electro-dyslexia...

Yves, I am so so so sorry about this.

Replaced the 3 resistors and everything is working without any kind of glitch.

Actually sounds awesome!!!

Thanks for the help, and sorry again :S

Shame on me Sad

Embarassed Embarassed Embarassed Embarassed Embarassed Embarassed Embarassed Embarassed Embarassed Embarassed
Back to top
View user's profile Send private message
Snaper



Joined: Feb 28, 2014
Posts: 217
Location: Hungary

PostPosted: Sat Jan 24, 2015 12:50 pm    Post subject: Reply with quote  Mark this post and the followings unread

wackelpeter wrote:
and btw is R11 an 15k resistor looks different to R19 to R21... ? i'm not good at reading those colour codes...

edit: could it be that this is a 15k resistor and R19 to R21 aren't...

checking with the 1k5 or 15K resistors in my box they start with brown for 1 and then green for 5 then followed by the code for multiplication and tolerance... don't know if there are different colour codes usual...

your's beginning with green and then brown look like they are something with 51... could be possible that i'm totally wrong

Embarassed
Back to top
View user's profile Send private message
Snaper



Joined: Feb 28, 2014
Posts: 217
Location: Hungary

PostPosted: Sat Jan 24, 2015 12:51 pm    Post subject: Reply with quote  Mark this post and the followings unread

yusynth wrote:
You should have 0.070 at pin 1 of the TL072 check thoroughly all the components connected to pins 1,2 and 3 of the TL074, check for a short between tracks. Remove TL072 and repeat the measures at pin 1,2 and 3 of the TL072

Now yes, all voltages are correct!
Back to top
View user's profile Send private message
yusynth



Joined: Nov 24, 2005
Posts: 1314
Location: France

PostPosted: Sat Jan 24, 2015 12:53 pm    Post subject: Reply with quote  Mark this post and the followings unread

all is fine then
_________________
Yves
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic Moderators: Scott Stites
Page 1 of 2 [28 Posts]
View unread posts
View new posts in the last week
Goto page: 1, 2 Next
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


Forum with support of Syndicator RSS
Powered by phpBB © 2001, 2005 phpBB Group
Copyright © 2003 through 2009 by electro-music.com - Conditions Of Use