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 
 Forum index » DIY Hardware and Software » Lunettas - circuits inspired by Stanley Lunetta
40106 oscillator module build - help please
Post new topic   Reply to topic Moderators: mosc
Page 1 of 1 [13 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
Vanwonky



Joined: Jul 24, 2013
Posts: 9
Location: Perth, Australia

PostPosted: Thu May 22, 2014 7:35 am    Post subject: 40106 oscillator module build - help please
Subject description: Can't get this working correctly
Reply with quote  Mark this post and the followings unread

Howdy All,
I have been lurking (as a member) here for ages having a ball breadboarding all sorts of stuff and driving the family nuts with noises coming out of the office! Time has come to get my Lunetta synth actually made but this module is driving me nuts.
Just a 40106 using all six in/outs. 4 have switchable caps for a bit of variation. I have some big caps in there (330μF is the largest) since I want some really slow clock timing for some and up to 1μF and above that and the green I don't even know the value of but sound good. I am using the circuit below on the 4 with switches and just straight on the other two. I didn't breadboard this with switches I will admit. Something is very wrong though. For starters if the voltage is at 9 volts it will oscillate for a few seconds then stop. If I take the voltage to around 8 and even down to 5 volts it works sort of right but the sound is still a bit wonky.

As far as I can tell the wiring seems correct but I am missing something fundamental here. I have attached a couple of images of the module wiring and front.
Please note that the image doesn't show my connection to ground on the negative rail for the caps as I used a crocodile lead whilst testing.
Yellow wires are outputs. Blue are inputs.
Hope someone can help. I have spent hours trying to fault find this with different wiring arrangements and caps. Please let me know if you need more info.

Cheers
Dave


LFO_Mod_40106schema.jpg
 Description:
Schematic
 Filesize:  21.53 KB
 Viewed:  1112 Time(s)

LFO_Mod_40106schema.jpg



LFO_Mod_wiring_closeup.jpg
 Description:
Wiring close up
 Filesize:  159.08 KB
 Viewed:  16 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

LFO_Mod_wiring_closeup.jpg



LFO_Mod_wiring.jpg
 Description:
All six pots
 Filesize:  164.77 KB
 Viewed:  17 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

LFO_Mod_wiring.jpg



LFO_Mod_front.jpg
 Description:
Front of panel
 Filesize:  73.47 KB
 Viewed:  24 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

LFO_Mod_front.jpg


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



Joined: Jan 14, 2010
Posts: 1652
Location: Moon Base
Audio files: 333

PostPosted: Thu May 22, 2014 8:59 am    Post subject: Reply with quote  Mark this post and the followings unread

welcome party!

Hmm that's some unusual behaviour and looking at the photos that part seems to be wired correct.
Do you have a photo of the part with the chip, maybe I can spot something there.

that's a very nice looking panel btw Very Happy

_________________
"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
Blue Hell
Site Admin


Joined: Apr 03, 2004
Posts: 20480
Location: The Netherlands, Enschede
Audio files: 147
G2 patch files: 318

PostPosted: Thu May 22, 2014 9:18 am    Post subject: Reply with quote  Mark this post and the followings unread

Large electrolytics can be a problem in this circuit as the leakage current of the caps will be in about the same range as the minimum current flowing through the pot .. this may stop oscillations.

However I' d expect that effect to be worse on lower supply voltages.

Yup, very nice panel!

_________________
Jan
Back to top
View user's profile Send private message Visit poster's website
elektrouwe



Joined: May 27, 2012
Posts: 41
Location: Germany

PostPosted: Thu May 22, 2014 11:39 am    Post subject: Reply with quote  Mark this post and the followings unread

Blue Hell wrote:
Large electrolytics can be a problem...
However I' d expect that effect to be worse on lower supply voltages.
...

I also guess that 's the problem. And it is worse with higher operating voltage, because the average cap voltage ( around V/2 ) causes a higher leakage current through the caps then. So the behavior matches theory Wink
you can try to cure the bad cap behavior : take them out and attach them
to a power supply with the rated cap voltage for some minutes. Don't forget
to discharge them before resoldering them into your Lunetta !
Another option: compensate the leakage current by wiring a 22k..100k resistor from the caps to +9V.

BTW: I'd rather use small non-electrolyte Cs and use a 4040 to get the low freqs.
Back to top
View user's profile Send private message
Vanwonky



Joined: Jul 24, 2013
Posts: 9
Location: Perth, Australia

PostPosted: Thu May 22, 2014 5:00 pm    Post subject: Reply with quote  Mark this post and the followings unread

PHOBoS - Thanks for the welcome. After the dodgy behaviour on stripboard I went back to breadboard so I can take a pic of that later but really it is just the in/out into the 40106 plus power. I stripped the board of all other parts to make sure they aren't causing problems.

Blue Hell / elektrouwe - Yes the caps might be an issue to look at. I have had no problems using any of those caps breadboarded. I will try smaller values and then non-electrolyte. As you say elektrouwe a 4040 for the slow rates. But grrrr! This should work!

Thanks for the comments on the panel guys. Blinkys to come. The panel is 6mm satin perspex. The LEDs will sit just touching the back giving a funky glow if I get this thing working Laughing
Back to top
View user's profile Send private message
corex



Joined: Mar 02, 2010
Posts: 107
Location: Las Vegas

PostPosted: Fri May 23, 2014 12:45 pm    Post subject: Reply with quote  Mark this post and the followings unread

That's an interesting point about electrolytic leakage currents. I've noticed that 10uF electrolytic is about the biggest size I've been able to use (on +12V supply) but I was never sure why. I normally prefer to use 1uF film caps (just the biggest non-electrolytic I have).

But if you've tried it on breadboard with those caps, Vanwonky... weird.
Back to top
View user's profile Send private message
Vanwonky



Joined: Jul 24, 2013
Posts: 9
Location: Perth, Australia

PostPosted: Fri May 23, 2014 7:15 pm    Post subject: Reply with quote  Mark this post and the followings unread

Yeah thanks Corex. I tried some smaller caps but still getting some unpredictably insane results from nothing to dodgy unsteady oscillations. I wonder if the freeform wiring has some anntenae effect (pardon my basic electronics)? Also I bought the pots from Futurlec for 55 cents (AUS) each which seemed dirt cheap. 100K but they vary anywhere from 89 - 110K! Maybe the contacts in them are crappy as well. Anyway - I think I might just get all the caps back onto the stripboard so I can just get this built. It means a few more wires to the switches etc. but so be it. Fingers crossed.


corex wrote:
That's an interesting point about electrolytic leakage currents. I've noticed that 10uF electrolytic is about the biggest size I've been able to use (on +12V supply) but I was never sure why. I normally prefer to use 1uF film caps (just the biggest non-electrolytic I have).

But if you've tried it on breadboard with those caps, Vanwonky... weird.
Back to top
View user's profile Send private message
Blue Hell
Site Admin


Joined: Apr 03, 2004
Posts: 20480
Location: The Netherlands, Enschede
Audio files: 147
G2 patch files: 318

PostPosted: Sat May 24, 2014 3:58 am    Post subject: Reply with quote  Mark this post and the followings unread

Well .. big ccaps .. the 330 µF you menetioned earlier might not work when it's very leaky .. but stuff around 10 µF should just work, if not the first one at least the 2nd one and all following ..

Anyway, not an empty battery eh?

_________________
Jan
Back to top
View user's profile Send private message Visit poster's website
Vanwonky



Joined: Jul 24, 2013
Posts: 9
Location: Perth, Australia

PostPosted: Sat May 24, 2014 6:04 am    Post subject: Reply with quote  Mark this post and the followings unread

Jan - I am putting the big caps back in the drawer till another day! Tomorrow I will pull everthing apart and solder the caps (smaller ones Shocked onto the stripboard. "Anyway, not an empty battery eh?" - are you actually asking me if I am using an old battery or is that an 'electronics' joke I don't know yet Very Happy ? Just in case let me tell you I am using a lab power supply.

Blue Hell wrote:
Well .. big ccaps .. the 330 µF you menetioned earlier might not work when it's very leaky .. but stuff around 10 µF should just work, if not the first one at least the 2nd one and all following ..

Anyway, not an empty battery eh?
Back to top
View user's profile Send private message
Blue Hell
Site Admin


Joined: Apr 03, 2004
Posts: 20480
Location: The Netherlands, Enschede
Audio files: 147
G2 patch files: 318

PostPosted: Sat May 24, 2014 6:21 am    Post subject: Reply with quote  Mark this post and the followings unread

Power supply, ok, got it ... heh .. you would not be the first one to run into trouble on a battery assumed to be full ... so was just checking to make sure.
_________________
Jan
Back to top
View user's profile Send private message Visit poster's website
DUBmatze



Joined: Feb 18, 2013
Posts: 91
Location: south Germaica (schwabilon)

PostPosted: Sat May 24, 2014 7:21 am    Post subject: Reply with quote  Mark this post and the followings unread

...so i keep asking dumb questions... Wink

you double checked the ground connection of the 40106?

using a normal 330u cap shud work fine. i have a osc here (from a 4093) with a socket for the caps. I have tested 470u, 1000u and 2200u. the only differnce is i have a 1.1k resistor in series to the pot and iam running my lunetta stuff at 5V from a 7805.

the panel is looking nice.

_________________
http://matze.reggaestriert.de/diy-projekte/
Back to top
View user's profile Send private message Visit poster's website
Vanwonky



Joined: Jul 24, 2013
Posts: 9
Location: Perth, Australia

PostPosted: Sat May 24, 2014 8:43 am    Post subject: Reply with quote  Mark this post and the followings unread

Hey DUBmatze - as far as I am concerned there are no dumb questions! Yes I quadruple checked the ground and everything else. I tried a different breadboard, 3 power supplys including a 9 volt battery and 4 different 40106's with all the same results. Very weird. I will strip it down and check all the components. I checked for dry joints everywhere but they all seemed fine. Mysterious. Mad

DUBmatze wrote:
...so i keep asking dumb questions... Wink

you double checked the ground connection of the 40106?

using a normal 330u cap shud work fine. i have a osc here (from a 4093) with a socket for the caps. I have tested 470u, 1000u and 2200u. the only differnce is i have a 1.1k resistor in series to the pot and iam running my lunetta stuff at 5V from a 7805.

the panel is looking nice.
Back to top
View user's profile Send private message
Vanwonky



Joined: Jul 24, 2013
Posts: 9
Location: Perth, Australia

PostPosted: Sun May 25, 2014 6:24 am    Post subject: Reply with quote  Mark this post and the followings unread

OK - fixed and working beautifully Very Happy . I wired all the caps to the stripboard. It meant 2 more wires to each switch which means wires everywhere but who cares - it works! Used the big caps again as well - down to 470µF and no problems. Wished I could work out why the original method didn't work but now I can move on - yeehaa! Thanks to you guys for trying to help. I will have plenty more questions as I go no doubt Razz .


LFO_module_rework.jpg
 Description:
LFO switch wiring reworked
 Filesize:  142.16 KB
 Viewed:  6 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

LFO_module_rework.jpg



LFO_module_rear_rework.jpg
 Description:
LFO wiring reworked
 Filesize:  142.03 KB
 Viewed:  7 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

LFO_module_rear_rework.jpg



Seq_LFO_Panels.jpg
 Description:
Sequencer and LFO module
 Filesize:  150.19 KB
 Viewed:  12 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

Seq_LFO_Panels.jpg


Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic Moderators: mosc
Page 1 of 1 [13 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 » Lunettas - circuits inspired by Stanley Lunetta
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