electro-music.com   Dedicated to experimental electro-acoustic
and electronic music
 
    Front Page  |  Radio
 |  Media  |  Forum  |  Wiki  |  Links
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 
go to the radio page Live at electro-music.com radio 1 Please visit the chat
poster
 Forum index » DIY Hardware and Software
Simple ribbon controller for V/Hz synth
Post new topic   Reply to topic Moderators: jksuperstar, Scott Stites, Uncle Krunkus
Page 1 of 1 [21 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
nicolas3141



Joined: May 25, 2007
Posts: 185
Location: Christchurch, New Zealand

PostPosted: Thu Mar 05, 2009 2:24 am    Post subject: Simple ribbon controller for V/Hz synth Reply with quote  Mark this post and the followings unread

Continuing my simple synth series. Design goals: simple and educational circuit, 9V battery powered. V/Hz with CV output of about 1-5V giving at least two octaves of reasonable linearity. Stripboard layout shown with no cuts required. If you have a 5 or 6V reference voltage already available you can use that instead of C1 and U1. If you are building it into your synth you can use the main power supply instead of the battery and you won't need the stereo socket with the power-on-when-plugged-in earthing arrangement. Multiple output sockets on this can be very handy in a modular synth.

Finding suitable tape is the hardest bit. I have tested quite a few video/audio/computer-backup tapes and found that pro-grade tapes from the 80s or earlier are the most likely to be suitable (amongst older pro-grade tapes I found I needed to test about a dozen tapes to find two or three suitable ones). Modern consumer grade VHS is not so likely to be suitable. I think you want somewhere between 10K and 100K per 10cm of tape. Most tapes are more like 1M or more over that distance which is too high to be useful. I have found one oddball that was about 3K per 10cm.

One thing to note is that the contact resistance can be quite high. For example if you get a reading of 100K over 10cm, 25K of that might be the probe to tape contact resistances. So 1cm would read about 30K. This doesn't usually matter too much with a three wire voltage divider type circuits like this, but will affect the linearity slightly.

I have some quarter inch tape from a computer backup cartridge and some half inch tape from professional TV betacam that both give me a reading of just under 100K per 10cm. Both work well with 25-30cm of tape as the ribbon, but the betacam tape seems to wear out much much faster. I stick the tape down with double sided sticky tape. Long and high resistance ribbon controllers are more likely to pick up hum and noise. C3 is there to quite that down, but does slow the response slightly. You may need to adjust the value of C3. Use the smallest value that still kills the noise.

You only need to find one tape that works and it will supply you and everyone you know with ribbon controllers for the rest of your life including regular replacements of the ribbon if necessary. So if there is anyone in Christchurch, New Zealand who needs some suitable tape, feel free to contact me.

Cheers,
Nicolas


ribbon-controller.JPG
 Description:
 Filesize:  111.92 KB
 Viewed:  6624 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

ribbon-controller.JPG


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



Joined: Aug 14, 2005
Posts: 1307
Location: Björkvik, Sweden
Audio files: 2

PostPosted: Thu Mar 05, 2009 3:03 am    Post subject: Reply with quote  Mark this post and the followings unread

Wow! Very Happy

Is it possible to make a thread with the collection of all your current and coming circuits. Or even a subforum? Very Happy

I really like these simple synth circuits. Cool

_________________
YouTube channel
flickr photostream
http://loxodrom.blogspot.com
http://www.garageband.com/artist/loxodrom
http://soundcloud.com/loxodrom
Back to top
View user's profile Send private message
creatorlars



Joined: Nov 26, 2007
Posts: 524
Location: Denton, TX
Audio files: 4

PostPosted: Thu Mar 05, 2009 9:50 am    Post subject: Reply with quote  Mark this post and the followings unread

This is awesome! I have a Korg Micro-Preset that is V/Hz that needs to be recased. I tried making a ribbon controller for it before because I dislike the keyboard and wanted to turn it into a ribbon controller based synth.

I dug out all my old VHS tapes and out of 30 or 40 I only found one or two that are 10K which seem to work (except not with the Korg, being V/Hz.) Only bad thing is that it was my Peewee Herman's Christmas Special tape! Sad But now I can resurrect this project.

I second the motion for a website or single thread with all of your schematics! Information on adapting for standard modular levels/power would be great too.
Back to top
View user's profile Send private message Visit poster's website AIM Address
nicolas3141



Joined: May 25, 2007
Posts: 185
Location: Christchurch, New Zealand

PostPosted: Fri Mar 06, 2009 4:01 am    Post subject: Reply with quote  Mark this post and the followings unread

Matching VCO - http://electro-music.com/forum/post-231723.html
Back to top
View user's profile Send private message
Dego



Joined: Apr 22, 2008
Posts: 139
Location: Sweden

PostPosted: Mon May 25, 2009 6:44 am    Post subject: Reply with quote  Mark this post and the followings unread

Pehr wrote:
Wow! Very Happy

Is it possible to make a thread with the collection of all your current and coming circuits. Or even a subforum? Very Happy

I really like these simple synth circuits. Cool


I agree. It would be good to have them all together.

I have built the LFO, VCLFO (not tried the cv yet). I have the ADSR ready soon. Think I am going to build the filter as well. Smile
Just have to score a lm13600n first...
Back to top
View user's profile Send private message
Pehr



Joined: Aug 14, 2005
Posts: 1307
Location: Björkvik, Sweden
Audio files: 2

PostPosted: Mon May 25, 2009 10:00 am    Post subject: Reply with quote  Mark this post and the followings unread

[quote="Dego"]
Pehr wrote:
Just have to score a lm13600n first...


doesn't the 13700 work aswell?

_________________
YouTube channel
flickr photostream
http://loxodrom.blogspot.com
http://www.garageband.com/artist/loxodrom
http://soundcloud.com/loxodrom
Back to top
View user's profile Send private message
Dego



Joined: Apr 22, 2008
Posts: 139
Location: Sweden

PostPosted: Mon May 25, 2009 10:50 am    Post subject: Reply with quote  Mark this post and the followings unread

Yeah, but they are also expensive.
Mouser suggests this one as a replacement:
http://se.mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMutXGli8Ay4kEnP%2fCY8WwSLRooVB6dPAf4%3d

It is much cheaper...
Back to top
View user's profile Send private message
radek tymecki



Joined: Mar 22, 2009
Posts: 85
Location: PL

PostPosted: Sat May 08, 2010 2:29 am    Post subject: Reply with quote  Mark this post and the followings unread

u can use also NE5517N
Back to top
View user's profile Send private message Visit poster's website
nicolas3141



Joined: May 25, 2007
Posts: 185
Location: Christchurch, New Zealand

PostPosted: Sun Aug 01, 2010 2:23 am    Post subject: Reply with quote  Mark this post and the followings unread

Here is a suggestion for how to turn this circuit into a keyboard controller. This circuit is currently completely untested.

Cheers,
Nicolas


kbd.jpg
 Description:
 Filesize:  43.9 KB
 Viewed:  2029 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

kbd.jpg


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



Joined: Apr 02, 2010
Posts: 316
Location: Albuquerque, NM

PostPosted: Mon Jan 03, 2011 5:49 pm    Post subject: Reply with quote  Mark this post and the followings unread

just built one of these from my copy of "The Terminator"! This thing is awesome; I used a 5 volt reg and a 2n3904 and am getting just under 5 octaves on the Saw VCO. You rule Nicolas!

Which resistor would I need to sub in order to get a range control pot?
Back to top
View user's profile Send private message Visit poster's website
darkomen



Joined: Jun 21, 2010
Posts: 40
Location: USA

PostPosted: Tue Apr 12, 2011 6:32 am    Post subject: Reply with quote  Mark this post and the followings unread

How would I go about adding a gate and trigger out from your ribbon (or keyboard) controller in order to work with your modules?
Back to top
View user's profile Send private message
inlifeindeath



Joined: Apr 02, 2010
Posts: 316
Location: Albuquerque, NM

PostPosted: Tue Apr 12, 2011 8:04 am    Post subject: Reply with quote  Mark this post and the followings unread

the ouput can be used as a gate signal. it will gate for as long as you hold down the string. i used it successfully on my soundlab to trigger the AR gen
_________________
http://www.youtube.com/user/borisandfef
Back to top
View user's profile Send private message Visit poster's website
darkomen



Joined: Jun 21, 2010
Posts: 40
Location: USA

PostPosted: Tue Apr 12, 2011 8:53 am    Post subject: Reply with quote  Mark this post and the followings unread

Thanks for the reply. What about a trigger, could I use a schmitt-trigger configured as a one shot?

Also, semi-related to this thread. I see that the nicolas circuits use V/Hz, how do you determine the voltage needed to get a certain frequency?
Back to top
View user's profile Send private message
inlifeindeath



Joined: Apr 02, 2010
Posts: 316
Location: Albuquerque, NM

PostPosted: Wed Apr 13, 2011 5:53 am    Post subject: Reply with quote  Mark this post and the followings unread

try the one shot below, i would think it should work. not sure how to estimate frequency. you could always use a trim pot to change the range.


mm2logic.gif
 Description:
 Filesize:  10.34 KB
 Viewed:  1344 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

mm2logic.gif



_________________
http://www.youtube.com/user/borisandfef
Back to top
View user's profile Send private message Visit poster's website
darkomen



Joined: Jun 21, 2010
Posts: 40
Location: USA

PostPosted: Thu Apr 14, 2011 4:59 am    Post subject: Reply with quote  Mark this post and the followings unread

So I think I've figured out a good solution for a gate/trigger. If I have a comparator that compares the CV being played to 0V I could have it output a constant 5V for the gate as long as the note is on. For the trigger I found the CGS gate to trigger converter. I'm going to try this over the weekend to see how it work.
Back to top
View user's profile Send private message
darkomen



Joined: Jun 21, 2010
Posts: 40
Location: USA

PostPosted: Thu Apr 14, 2011 5:50 am    Post subject: Reply with quote  Mark this post and the followings unread

Also found this one from MFOS, which uses the one-shot 40106.

http://www.musicfromouterspace.com/analogsynth_new/HOT_TIPS/PDF/gatebuffer20090923_assembly.pdf[/url]
Back to top
View user's profile Send private message
inlifeindeath



Joined: Apr 02, 2010
Posts: 316
Location: Albuquerque, NM

PostPosted: Tue Mar 13, 2012 10:47 pm    Post subject: Reply with quote  Mark this post and the followings unread

just finished a dual verison. video here:http://youtu.be/rf0kp-jo_yI

better video tomorrow.

_________________
http://www.youtube.com/user/borisandfef
Back to top
View user's profile Send private message Visit poster's website
inlifeindeath



Joined: Apr 02, 2010
Posts: 316
Location: Albuquerque, NM

PostPosted: Wed Mar 14, 2012 11:09 pm    Post subject: Reply with quote  Mark this post and the followings unread

fyi, used the cv output for both VCO freq and to gate a VCA, works just fine.
Also, no voltage reg.

_________________
http://www.youtube.com/user/borisandfef
Back to top
View user's profile Send private message Visit poster's website
masterofstuff124



Joined: Sep 21, 2015
Posts: 23
Location: Miami, Florida

PostPosted: Thu Jan 12, 2017 1:27 pm    Post subject: Reply with quote  Mark this post and the followings unread

would this work on a soft potentiometer? seems similar enough.


what about converting to v/oct


thanks!
Back to top
View user's profile Send private message
beetleprofessor



Joined: Mar 27, 2017
Posts: 1
Location: Portland, OR

PostPosted: Mon Mar 27, 2017 4:07 pm    Post subject: Schematic for scaling of controller? Reply with quote  Mark this post and the followings unread

How would I add a knob to adjust the scaling of this controller? Like the knob on an expression pedal that changes the output level? I'm trying to build this using a premade soft-pot (https://www.sparkfun.com/products/8681), wanting to use it primarily as a pitch controller for a Moog sub37, and I'd like to be able to adjust the scaling of it on the fly, so I can use it to control down to, say, a semitone, and up to the full range of the oscillators, with a notch in between to quickly get to a scaling that corresponds to a standard key board. It seems like it also needs a way to track with the octave buttons, so that when it's scaled to the keyboard, it's corresponding to the correct octave.

Creatively, I want to be able to be playing along on the keyboard, and then use the ribbon to either 1)transition to playing entirely on the ribbon, 2)use the ribbon to perform a controlled glissando to another note, then go seemlessly back to the keyboard, 3)use a scaling knob in real time to perform multi octave glissandos from one note, then to be able to suddenly use the ribbon controller to adjust the intonation of the note I land on, or of the next note I play, and 4)use the scaling knob to make the controller immediately flexible as a controller for other destinations than pitch, especially since on the sub37, you can assign the destination of each CV input, and save that destination per preset.

This may be too much to ask for. I don't know. I'm extremely new to circuit building, so any over-explaining is much appreciated, especially about what I need to do to select the correct components in relation to the resistance of this soft-pot.
Back to top
View user's profile Send private message
Project_2501



Joined: Jan 31, 2018
Posts: 68
Location: Los Angeles

PostPosted: Tue Mar 27, 2018 5:41 pm    Post subject: Reply with quote  Mark this post and the followings unread

Does anyone have any tape scraps leftover from their build?????? I'm only asking to save some time fishing through thrift ship vhs tapes.

I'll pay for postage/envelope if you have leftover strips of ribbon tape. pm me Very Happy
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 1 of 1 [21 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
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


Forum with support of Syndicator RSS
Powered by phpBB © 2001, 2005 phpBB Group
Copyright © 2003 through 2009 by electro-music.com - Conditions Of Use