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
  Faux Pas Quartet and friends Music From Last Thursday
Please visit the chat
 Forum index » DIY Hardware and Software
Very simple sawtooth VCO (V/Hz)
Post new topic   Reply to topic Moderators: jksuperstar, Scott Stites, Uncle Krunkus
Page 4 of 4 [82 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Goto page: Previous 1, 2, 3, 4
Author Message
Yipdeceiver



Joined: Apr 07, 2014
Posts: 4
Location: Athens GA

PostPosted: Mon Apr 07, 2014 3:47 pm    Post subject: Reply with quote  Mark this post and the followings unread

A friend and I built this and it's pretty rad. One thing though, patching it through the ext signal in on the ms10 and the extra oscillator doesn't respond to the lfo. Is there anyway to make that happen? Might be more of an ms10 question I guess, but I figured you guys might have some ideas.
Back to top
View user's profile Send private message
bod



Joined: Apr 28, 2009
Posts: 148
Location: Glasgow

PostPosted: Tue Apr 08, 2014 4:28 am    Post subject: Reply with quote  Mark this post and the followings unread

you would need to take a signal from the ms10 lfo output and connect it to the cv input of the oscilator for that to work, but it would work.
Back to top
View user's profile Send private message
Yipdeceiver



Joined: Apr 07, 2014
Posts: 4
Location: Athens GA

PostPosted: Thu Apr 24, 2014 1:30 pm    Post subject: Reply with quote  Mark this post and the followings unread

I've been looking around and found this cv scaling circuit. I used an lm324 because that's what I had lying around so I have the extra op amp already. Think it would be worth it to throw this in front of the cv input in an attempt to get this vco to track correctly? Or would that work?


image.jpg
 Description:
 Filesize:  106.06 KB
 Viewed:  54 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

image.jpg


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



Joined: Apr 07, 2014
Posts: 4
Location: Athens GA

PostPosted: Thu Apr 24, 2014 2:57 pm    Post subject: Reply with quote  Mark this post and the followings unread

I went ahead and bread boarded this up and after fiddling with resistors for a while I think I've got something. It tracks reasonably well with my ms 10 now. The lowest note and the highest note are perfectly in tune with a little bit of variation in the middle octave. Obviously it's not perfect but it is definitely better. I'm not sure why it is deviating in the middle octave though. Any thoughts?
Back to top
View user's profile Send private message
Citezyne



Joined: Jan 09, 2015
Posts: 17
Location: Australia

PostPosted: Sat Jan 10, 2015 8:09 am    Post subject: Reply with quote  Mark this post and the followings unread

nicolas3141 wrote:
Yes, there are three main approaches to powering audio circuits from a single 9V battery (or any single ended supply).

1. Use a voltage divider to create a midpoint voltage, buffer it with a spare op-amp, then use this as your 0V reference throughout your circuit. The resistors can be large (50-100K). This is a good way to do it if you have a spare op-amp available.

2. Use a voltage divider to create a midpoint voltage, buffer it with capacitors, then use this as your 0V reference throughout your circuit. The caps need to be largish (10-1000uF) and the resistors smallish (1-10K). This usually works very well, but can create an added drain on the battery. If you want to have a power status LED this can be combined with the voltage divider as I did in the bleeper circuit to enhance the performance.

3. Use separate voltage dividers throughout the circuit wherever you need a 0V reference. This works well for smaller circuits and used to be the preferred approach for discrete transistor circuits. It reduces the risk of unforeseen feedback loops via the 0V connection which can occasionally lead to odd behaviour in some circuits.

Nicolas


Hi again,

I'm curious to know, is there a formula to work out the resistor and cap sizes? I'm keen to put together a power supply like this on a bread board to play around more with some of your other designs. Mostly I'd use a 9v battery or a 12 volt PC PSU supply.

Also working on your simple bleeper using 2 TL074's however I don't have the 750r resistor or the 33k ones so have to wait till payday for them.

Love your work, super simple for a beginner like myself, biggest I have built is an 8 step APC.
Back to top
View user's profile Send private message
nicolas3141



Joined: May 25, 2007
Posts: 150
Location: Christchurch, New Zealand

PostPosted: Tue Jan 13, 2015 3:50 pm    Post subject: Reply with quote  Mark this post and the followings unread

If you are wanting to go with option 2 - two resistors and a cap to create a 0V reference - then a rule of thumb would be resistors an order of magnitude smaller than the resistors in your circuit and the cap at least an order of magnitude (or two) bigger than any caps in the circuit. But option 1 is much better if you can buffer you 0V reference with an op-amp.

Nicolas
Back to top
View user's profile Send private message
Citezyne



Joined: Jan 09, 2015
Posts: 17
Location: Australia

PostPosted: Wed Jan 14, 2015 4:55 am    Post subject: Reply with quote  Mark this post and the followings unread

nicolas3141 wrote:
If you are wanting to go with option 2 - two resistors and a cap to create a 0V reference - then a rule of thumb would be resistors an order of magnitude smaller than the resistors in your circuit and the cap at least an order of magnitude (or two) bigger than any caps in the circuit. But option 1 is much better if you can buffer you 0V reference with an op-amp.

Nicolas


I would use the op amp version as recommended, I have a few TL0XX lying around that would suit the job.

Thank you again for your help, your simple Designs gave me hope when i felt that all hope was lost!

Keep up the Awesome work!
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic Moderators: jksuperstar, Scott Stites, Uncle Krunkus
Page 4 of 4 [82 Posts]
View unread posts
View new posts in the last week
Goto page: Previous 1, 2, 3, 4
Mark the topic unread :: View previous topic :: View next topic
 Forum index » DIY Hardware and Software
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