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
  Jez Adventures in Sound
Please visit the chat
 Forum index » DIY Hardware and Software » Thomas Henry designs
LM VCO or X4046 VCO?
Post new topic   Reply to topic Moderators: Scott Stites
Page 1 of 1 [7 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
elmegil



Joined: Mar 20, 2012
Posts: 1484
Location: Chicago
Audio files: 14

PostPosted: Sat Jul 21, 2012 10:46 pm    Post subject: LM VCO or X4046 VCO? Reply with quote  Mark this post and the followings unread

I'm ready to test my El Cerrito/XR VCO build, so of course my mind turns to "what's next" Smile

I started out with the intent of building everything in the ASft21C book, but I've ordered X4046 boards from Fonik (get them while they're hot!) and my own comparison of the features vs space leans toward the X4046... as well as the fact that it's a newer and slightly simpler design.

Of course these are paper comparisons. I'm curious if anyone who's actually heard both has an opinion of one versus the other.

Of course in the long run, I will probably build both, but this is more a matter of ordering my backlog and picking the next thing to come off the stack.

Actually I probably ought to do the VCA/VCF next since it's on the breadboard.... Very Happy But then after that...
Back to top
View user's profile Send private message
elmegil



Joined: Mar 20, 2012
Posts: 1484
Location: Chicago
Audio files: 14

PostPosted: Wed Aug 08, 2012 10:27 pm    Post subject: Reply with quote  Mark this post and the followings unread

Funny how everything takes longer than you think it will.

Finally got to testing and calibration this week, for real, ready to finish the panel and put it in the rack.

Nobody has any opinions about this? Smile
Back to top
View user's profile Send private message
Mongo1



Joined: Aug 11, 2011
Posts: 411
Location: Raleigh NC

PostPosted: Wed Jan 02, 2013 1:53 pm    Post subject: Reply with quote  Mark this post and the followings unread

I was actually just looking at a similar issue - I'm building a small portable synth (serge format), and was trying to choose the VCOs for it. I have boards for El Cerrito, 4046, and Buchla 281. Based on the feature set, board size, and a bunch of other factors I think I'm going to go for the 4046s. I really wanted to try the Buchlas, but the 'build' thread on muffs is pretty hard to follow, and you can't sync those VCOs. The 4046 looks pretty clean to me, and offers a lot of waveforms, so I ended up there.

Gary
Back to top
View user's profile Send private message Send e-mail
elmegil



Joined: Mar 20, 2012
Posts: 1484
Location: Chicago
Audio files: 14

PostPosted: Wed Jan 02, 2013 2:42 pm    Post subject: Reply with quote  Mark this post and the followings unread

Be warned, the X4046 is known to be something of a pain to calibrate.....

I actually have mine built and paneled, and was going through the calibration over the break, and did not finish it. I was also working on a soundlab+ that I wanted to finish more, so I shelved the X4046 to calibrate later.

I did find the el Cerrito easier to calibrate, though I can't recall now if I got it down to the gnat's eyebrow or not. Until now I've only had the one VCO (the el Cerrito) in my rig, so I haven't had anything I could do to validate that it tracked equally to another VCO.

Not trying to talk you out of it.... The X4046 build is a joy, I really like Fonik's board.

Edit: I thought the Buchla 281 was a function generator not an oscillator?
Back to top
View user's profile Send private message
roglok



Joined: Aug 28, 2010
Posts: 159
Location: uptown

PostPosted: Thu Jan 03, 2013 6:57 am    Post subject: Reply with quote  Mark this post and the followings unread

I did not find the X-4046 hard to calibrate. FWIW it depends on the 4046 manufacturer. Some makes are supposed to be impossible to calibrate properly. This is noted both in Scott Stites'/Thomas Henry's and Fonik's docs:

http://www.birthofasynth.com/Thomas_Henry/Pages/X-4046.html#Miscellaneous_Notes
http://www.modular.fonik.de/pdf/TH_X-4046_VCO.pdf

I have used NXP HEF4046 and mine tracks well over 5 octaves without having spent too much time on it...
Back to top
View user's profile Send private message
elmegil



Joined: Mar 20, 2012
Posts: 1484
Location: Chicago
Audio files: 14

PostPosted: Thu Jan 03, 2013 7:49 am    Post subject: Reply with quote  Mark this post and the followings unread

Fair enough, though Thomas' docs state at length that it takes him 2 hours to calibrate, and I assume he's using one of the preferred manufacturers....

Quote:
It usually takes me a couple hours to tune the X-4046 VCO. The entire time I keep a close watch on the DVM to make sure I'm really getting a 1V step between octaves and that temperature drift hasn't affected my voltage stepper (which I can easily recalibrate if need be). As my X-4046 VCO Test Results sheet shows, I was able to tune this fairly well from 80Hz to 10240Hz, although so far two other people have been unable to duplicate my results. I'm either lucky or deaf! But seriously, this VCO is harder to tune than most, the reason being that it doesn't provide perfect tuning throughout its range but requires spreading the errors out to regions where they are least noticeable. Despite this, it has enough going for it to make the extra time spent in tuning worthwhile, I think.
Back to top
View user's profile Send private message
fonik



Joined: Jun 07, 2006
Posts: 3759
Location: Germany
Audio files: 23

PostPosted: Sat Jan 05, 2013 2:35 pm    Post subject: Reply with quote  Mark this post and the followings unread

IIRC thomas did calibrate it to work for about 9 ocatves (nicely, but not perfect). i calibrated mine within minutes, and get about 5-6 usable octaves.
so with careful calibrating, and multiple recalibrating you will obviously get more out of it, however, it will take more time...

_________________
Posted Image, might have been reduced in size. Click Image to view fullscreen.
cheers,
matthias
____________
fonitronik at
FlickR (pix) / SoundCloud (sounds) / YouTube (vids) / Vimeo (vids) / facebook (news)
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic Moderators: Scott Stites
Page 1 of 1 [7 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 » Thomas Henry designs
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