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
  PHOBoS TWANG! on the radio
Please visit the chat
 Forum index » DIY Hardware and Software » MusicFromOuterSpace.com designs by Ray Wilson
MFOS VCO Scale Calibration
Post new topic   Reply to topic Moderators: dnny, Uncle Krunkus, v-un-v
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
keanenk



Joined: Jan 13, 2010
Posts: 4
Location: Hoboken, NJ

PostPosted: Thu Jan 14, 2010 12:03 am    Post subject: MFOS VCO Scale Calibration
Subject description: Noob needs help
Reply with quote  Mark this post and the followings unread

This is the first VCO module I built and I am not sure how to properly adjust it. I couldn't get it to track properly using a tempco. The trim adjustments (R16) would max out with it in. I am assuming the tempco is somehow not working correctly. I had to use a 2k resistor for R24 instead and then finally I could set it to get the proper hertz... 100hz at 0v, 800hz at 3v and 3.2khz at 5v (my MIDI to CV doesn't go to 6v), but if I go through the notes, one will be sharp and the next will be flat and it sounds off. If I go from the note C1 (0v) to C4 (3v) it will be perfect, but C6 (5v) is like a B, but it reads 3.2khz on my meter. Any ideas?? Confused
Back to top
View user's profile Send private message
keanenk



Joined: Jan 13, 2010
Posts: 4
Location: Hoboken, NJ

PostPosted: Fri Jan 22, 2010 3:40 pm    Post subject: Reply with quote  Mark this post and the followings unread

Anybody have any ideas?

Still not working correctly. It's very depressing.........
Back to top
View user's profile Send private message
jordroid



Joined: Jan 17, 2010
Posts: 193
Location: ithaca, new york

PostPosted: Sun Jan 24, 2010 6:37 am    Post subject: Reply with quote  Mark this post and the followings unread

I don't have much of any advice for you but i thought i would drop by for moral support. It sounds you are going by Rays' calibration instructions on the most recent VCO page, but it looks like a pretty tweaky and potentially frustrating experience. Sorry dude, i looked over the instructions and i've got nothin' for you. Good luck though and hopefully one of the smarty pants's will be along to help out. You will get it working eventually, but i feel your pain in the meantime.
Back to top
View user's profile Send private message
keanenk



Joined: Jan 13, 2010
Posts: 4
Location: Hoboken, NJ

PostPosted: Sun Jan 24, 2010 2:19 pm    Post subject: Reply with quote  Mark this post and the followings unread

Thanks! I appreciate the moral support in these tough times Smile

I think it's possible I am not calibrating it right. Does anyone have any tips or did anyone do it differently than the process listed on the site?

Also, my sine and triangle waves sound very flat and lifeless. On my scope they look perfect though.
Back to top
View user's profile Send private message
haxster



Joined: Feb 01, 2006
Posts: 245
Location: MONTEREY PARK, CA 91754
G2 patch files: 2

PostPosted: Mon Jan 25, 2010 2:32 am    Post subject: Reply with quote  Mark this post and the followings unread

Maybe this txt file will help. It is similar to what your doing already.


VCO TUNNING.TXT
 Description:

Download
 Filename:  VCO TUNNING.TXT
 Filesize:  2.14 KB
 Downloaded:  268 Time(s)

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



Joined: Jan 13, 2010
Posts: 4
Location: Hoboken, NJ

PostPosted: Thu Jan 28, 2010 1:35 am    Post subject: Reply with quote  Mark this post and the followings unread

Thanks for the link.

I tried it out and I am still not scaling correctly...

Anybody want to buy a half working VCO??
Back to top
View user's profile Send private message
RF



Joined: Mar 23, 2007
Posts: 1500
Location: Northern Minnesota, USA
Audio files: 28

PostPosted: Thu Jan 28, 2010 8:09 am    Post subject: Reply with quote  Mark this post and the followings unread

Check and double check your cap and resistor values.
You CAN get this working...

bruce

_________________
www.sdiy.org/rfeng

"I want to make these sounds that go wooo-wooo-ah-woo-woo.”
(Herb Deutsch to Bob Moog ~1963)
Back to top
View user's profile Send private message
haxster



Joined: Feb 01, 2006
Posts: 245
Location: MONTEREY PARK, CA 91754
G2 patch files: 2

PostPosted: Thu Jan 28, 2010 10:33 am    Post subject: Reply with quote  Mark this post and the followings unread

R24 has to be 2k
R16 has to be a 100ohm Multiturn Trimmer
R19 has to be 470R

R9 I use 470R instead of 4k7, this garantees you don't run out of trimmer for the higher section of tracking.
R11 I use 100k instead of 20k

These mods make the vco sometimes Vanish, you need to turn the 100k trimmer until it comes back to earth and you hear it again. Then you can start the calibration.

I use a cheapo 100ppm 2k Tempco and 2n2222A trannies and i have never got one not to track. Sure it drifts a little bit but It still lands on the note. It is only noticable with 2 vco's.

Yeah you can get this working. It's just frustrating at first.
Back to top
View user's profile Send private message
jordroid



Joined: Jan 17, 2010
Posts: 193
Location: ithaca, new york

PostPosted: Sun Jan 31, 2010 9:06 am    Post subject: Reply with quote  Mark this post and the followings unread

I don't know if you have seen this yet, i think it's pretty new-

http://www.musicfromouterspace.com/analogsynth/TRANSISTORMATCHER/TRANSISTORMATCHER.php

the three videos at the bottom detail oscillator tuning, what a guy that Ray is.
Back to top
View user's profile Send private message
hudsonnc



Joined: Feb 07, 2018
Posts: 1
Location: California

PostPosted: Wed Feb 07, 2018 9:17 am    Post subject: Reply with quote  Mark this post and the followings unread

I know it has been about 8 years, but did you ever get it working? I am in the same boat now...
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic Moderators: dnny, Uncle Krunkus, v-un-v
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 » MusicFromOuterSpace.com designs by Ray Wilson
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