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
Quick question! Switching sequencer!!
Post new topic   Reply to topic Moderators: mosc
Page 1 of 1 [10 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
KK303



Joined: Feb 13, 2012
Posts: 11
Location: UK

PostPosted: Thu May 24, 2012 5:25 am    Post subject: Quick question! Switching sequencer!! Reply with quote  Mark this post and the followings unread

Hi! Quick question!!

For a long time I've been trying to build this 8 step sequencer with the 4017 and haven't really been satisifed with the results driving a 555 from it. I am now very happy with the sound of a 40106, and I had an idea whilst connecting four oscillator outputs to a rotary switch and switching between the outputs that the sequencer really ought to be able to work with this principle. Struggled for a while until coming across a 4066 chip in something I bought. Intrigued I immediately checked the datasheet and lo and behold it looks like the answer to my sequencer trouble. Has anyone tried this, a quick mock up in circuit wizard seems to suggest I could build a 40106 sequencer with 2x40106, 2x4066, have my eight pots controlling the frequency of 8 different oscillators off the 40106, and use a 9th osc as the clock for the 4017, have the 8 outputs of the 4017 turning on each switch on the 4066 and hopefully, very smooth sequencing between multiple oscillators from the 40106's with fine tuning on each. Does it sound possible, am I thinking along the right lines? I have heard there can be noticable pops when switching with a 4066, would this occur? I do realise using 8 different oscillators for a sequencer is a bit overkill, but given how easy it is to get a nice square wave from the 40106 for pennies it seems a fair enough trade off....I'm also thinking that a 4040 on the end of the chain (in parallel?) could generate a sub oscillator (or two) along with the sequence....for a real self cotained bass line/lead generator...theres always the trick of driving one 40106 osc from another with a diode in reverse (i think?) for some fake-filterish sounds...maybe I could use 16 oscillators!?! I don't havea penny to my name till pay day so until I can buy a 4066 (which will inevitably mean buying new pots, box, knobs, wire, solder, yada yada!!!) I just have this idea kiling my mind, would be great to hear if anyone has tried same, till now I was never able to find anyone doing switching like this??
Back to top
View user's profile Send private message
JingleJoe



Joined: Nov 10, 2011
Posts: 876
Location: Lancashire, England
Audio files: 14

PostPosted: Thu May 24, 2012 7:44 am    Post subject: Reply with quote  Mark this post and the followings unread

Honestly I only read half your post but I think I have a good idea of what you're trying to do, let me read the rest, yeah you are doing how I thought you were. It's not really how other sequencers work.
While your idea is good, unless you want 8 different tracks or something I wouldn't go down that route.
I can save you alot of time and money and everything acctually with some tips and my latest design, yours for just 9,999,9,995 only joking Razz

Other sequencers switch in a series of control voltages to one VCO, thus allowing you to have only one oscillator. I'll attach a schematic for my VCO, I have used it in loads of things very successfully. You could even use the CV input of a 555 timer if you don't mind about pulse width variation.

The way I would do this with a 4017 is to connect all the outputs from the 4017 to potentiometers wired up as voltage dividers (while we are on the subject, isn't the 4017 ten outputs? Why limit yourself to 8? use all ten! Wink).
Then combine them with diodes. I suppose you could passively mix them...

Just remembered this! there you go, read that, it should answer alot of questions for you Wink

I'll be back with that vco circuit in a bit.

_________________
As a mad scientist I am ruled by the dictum of science: "I could be wrong about this but lets find out"


Green Dungeon Alchemist Laboratories
Back to top
View user's profile Send private message
DGTom



Joined: Dec 08, 2008
Posts: 210
Location: Adelaide
Audio files: 3
G2 patch files: 1

PostPosted: Thu May 24, 2012 7:47 am    Post subject: Reply with quote  Mark this post and the followings unread

It'll work. There will be clicks & pops but with squarewaves, odds are you will not hear them. It's a roundabout way to do it however.

Take a look at this page;

http://milkcrate.com.au/_other/sea-moss/

this drawing in particular;

http://milkcrate.com.au/_other/sea-moss/04_seq.gif

replace the 22Ks with 100K pots & you have the device you have described. 1 x 40106, 1 x 4051, 1 x 4040. Alot easier than building 8 seperate oscillators & the basic concept is very easy to expand on.

Add another 4051 & do 2 voices, make a little patchbay so that you can reassign the 4040 outputs to the 4051 control inputs.

Or try it a differant way; use the 4051 to switch capacitors & drive the 4040 at audio rates - you can make really nice 'filter' sounds this way Wink
Back to top
View user's profile Send private message
KK303



Joined: Feb 13, 2012
Posts: 11
Location: UK

PostPosted: Thu May 24, 2012 8:03 am    Post subject: Reply with quote  Mark this post and the followings unread

Aha...yes I have come across this circuit before....I think I see what you are saying. I just checked my local Maplin, they have 2 4051's and 1 4066, so i will pick those up and give this a spin tonight, it looks like the 4051 approach is really what i want tho! Thanks!!

Jinglejoe, yes I've built the baby8 in this manner before, but I was never happy with the sound it produced in the 555, it was a bit wimpy, this pulse width changing being offputting. Although I have had problems using voltage dividers....when i had my pots wired like this, I would find that an adjustment on one pot could change the resistance on another step, eventually leaving little room to sweep on the last step. When i just used it as a variable resistor with no ground, it worked ok, but I had problems when trying to use LED's...maybe theres something I am missing. On the getlofi site there was some transistor array introduced for some reason (to help with grounding?), but in the comments someone eventually proves with a spice simulation that it wasn't doing what they thought it was doing...although the link to that simulation is now dead.

If you have a better VCO than a standard 555 I would love to see it though!!! Smile Cheers!!!
Back to top
View user's profile Send private message
JingleJoe



Joined: Nov 10, 2011
Posts: 876
Location: Lancashire, England
Audio files: 14

PostPosted: Thu May 24, 2012 8:17 am    Post subject: Reply with quote  Mark this post and the followings unread

KK303 wrote:

If you have a better VCO than a standard 555 I would love to see it though!!! Smile Cheers!!!

Drew this up better especially for you Wink haha!
See attachments, pulse width is independant of pitch untill you reach the frequency limits of the vco and even then it only varies by about 2%. The saw wave will go triangular at high frequencies unless you have some sort of super diode Smile but this is designed for square waves/pwm.
It is really linear too, any type of cap works but I have had best results with polyester caps and other plastic based non-polarized ones.

P.S. I advise against maplin, find another electronics supplier nearby. PRS electronics in liverpool are great, less than one fifth the price of maplin and ten times more variety in component stock!


GDAL VCO.png
 Description:
 Filesize:  6.32 KB
 Viewed:  2150 Time(s)

GDAL VCO.png



_________________
As a mad scientist I am ruled by the dictum of science: "I could be wrong about this but lets find out"


Green Dungeon Alchemist Laboratories
Back to top
View user's profile Send private message
DGTom



Joined: Dec 08, 2008
Posts: 210
Location: Adelaide
Audio files: 3
G2 patch files: 1

PostPosted: Thu May 24, 2012 8:28 am    Post subject: Reply with quote  Mark this post and the followings unread

If its working / built right a baby 8 shouldn't have any interaction between pots.

Also, if you go the 4051 route don't hook up the pots exactly like the resistors in the sea moss drawing.

Wire them so the output pin of the 40106 goes to the same lug of each of the 8 pots, then wire the next door lug of each pot to each 4051 input - you want them in parallel not series. Its alot easier than messing with VCOs (for now!) & will sound the same as a 40106 wired up with a single pot.

Def. get both 4051s if you do, I think the best next step is to hook the clock oscillator up just like the voice, that way you have another row of pots to control the length of each note in the sequence. Bassline heaven!
Back to top
View user's profile Send private message
JingleJoe



Joined: Nov 10, 2011
Posts: 876
Location: Lancashire, England
Audio files: 14

PostPosted: Thu May 24, 2012 8:37 am    Post subject: Reply with quote  Mark this post and the followings unread

In addition to what DGtom says, it sounds like you have wired your pots up wrong in your baby 8 sequencer.
_________________
As a mad scientist I am ruled by the dictum of science: "I could be wrong about this but lets find out"


Green Dungeon Alchemist Laboratories
Back to top
View user's profile Send private message
nathanxl



Joined: Apr 24, 2012
Posts: 72
Location: Wa

PostPosted: Fri May 25, 2012 4:53 am    Post subject: Reply with quote  Mark this post and the followings unread

DGTom wrote:
Wire them so the output pin of the 40106 goes to the same lug of each of the 8 pots, then wire the next door lug of each pot to each 4051 input - you want them in parallel not series.


Im trying this, looks like where Im at currently too.
Bit difficult for me(noob) to decipher. Any schematic update on the original sea-moss circuit design for me and my small brain to gander at??

Interested in this.
Thanks
N
Back to top
View user's profile Send private message
DGTom



Joined: Dec 08, 2008
Posts: 210
Location: Adelaide
Audio files: 3
G2 patch files: 1

PostPosted: Fri May 25, 2012 5:35 am    Post subject: Reply with quote  Mark this post and the followings unread

Quick & Dirty

so get it on the breadboard first, should work with the values shown, hope it makes sense.

The top 4051 is the noise making bit, you can leave off the bottom part, that is for a variable clock.

there is a reset input & the last section of the 40106 generates a pulse at power on to make sure thr 4040 starts from 1


schmittquencer.png
 Description:
 Filesize:  16.36 KB
 Viewed:  115 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

schmittquencer.png


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



Joined: Dec 08, 2008
Posts: 210
Location: Adelaide
Audio files: 3
G2 patch files: 1

PostPosted: Fri May 25, 2012 5:41 am    Post subject: Reply with quote  Mark this post and the followings unread

oh yeah, if you want LEDs to tel you which step you are on, use a 4051, tie the comman pin (#3) to +ve via a resistor then wire up 8 leds to the outputs.

& experiment with the A/B/C inputs on the 4051 to make goofy sequences, just make sure if you do use the variable clock method to tie the 2 4051s address bits together. . . or not Very Happy

for example, if you use Q4, Q5 & Q6 to control the clock 4051 then the 8 step sequence will play at the same speed twice before it changes, good fun!


Edit; tap the output of the top left gate with a diode or resistor for the output, sorry. . . kinda forgot the important bit Rolling Eyes
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 [10 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