Any super simple CV keyboard schematics?

nerd of nerds · Joined: Aug 26, 2005 Posts: 9 Location: Nebraska

Hi!

I'm in the planning stages of my soundlab right now. I'd like to give my SL a small 1 or 2 octave flat keyboard (like the super spiffy one in the gallery) but i don't exactly know how Embarassed

this will be my first analog synthesizer ever... Embarassed

mosc · Posted: Fri Aug 26, 2005 6:02 am Post subject:

to electro-music.com, nerdy. Good to have you here.

No need to be embarassed about not know exactly what to do. There are many solutions, and don't rule out using a MIDI keyboard with a MIDI/CV converter. Also, consider just starting on the Sound Lab and rig up a simple performance interface with just a pot and a switch.

dnny

nerd of nerds · Joined: Aug 26, 2005 Posts: 9 Location: Nebraska

mosc · Posted: Fri Aug 26, 2005 1:51 pm Post subject:

CV -> control voltage. These are used to control oscillators, filters and other anlog modules.
Triggers -> signals that turn on/off modules, like envelope generators.

These are the two types of controls analog modular synths generally use.

MIDI is a digital interface that can be converted to CV and Trigger with an special device. The nice thing about MIDI is tha most modern synths generate it, as do computers. You can also buy neat low=cost MIDI keyboards and knob boxes.

nerd of nerds · Joined: Aug 26, 2005 Posts: 9 Location: Nebraska

mosc · Posted: Fri Aug 26, 2005 4:30 pm Post subject:

Well, if you build or buy a MIDI to CV converter, you will be in business. I'm sure if you look there are DIY solution. I bought one years ago. I know Deopfer makes these - others I'm sure.

SuperKoopa · Posted: Mon Sep 19, 2005 3:22 pm Post subject:

All my respect to Mr. Wilson but this:
http://www.cgs.synth.net/tube/controller.html

Is simpliest than the single bus keyboard !

the question is :could be this scaled for 1V/Oct?

Please can anybody answer me?

SuperKoopa · Posted: Sat Oct 08, 2005 6:51 am Post subject:

hi! i've tested this circuit with circuit maker software and it seems to work but i think that there's a problem. when a key is pulled down cv voltage goes to desired level (es. 83 mV) but when the key is relased cv goes to the highest level (if you use a 9V supply this level is 7V!). so probably if you play a patch with long decay in VCA the pitch doesn't stay at the previous level when you relase the key.Is this true?
i'm not an expert in cv voltages,i haven't built my SL and i'm still on planning!
what this project needs for fix this problem?
please answer me soon!

Uncle Krunkus · Posted: Sun Oct 09, 2005 1:38 am Post subject:

Yeah, I think you're right. As the note faded out (VCA) the pitch would rise.
Also I'm uncertain if it will put out 1V/Oct as the text talks about 2 1/2 octaves from a few millivolts to V+(12V). This doesn't add up.
I'm not sure how you would fix this. Still it looks worth experimenting with.

Uncle Krunkus · Posted: Sun Oct 09, 2005 1:52 am Post subject:

Hey Nerd of nerds,
Good to have you on the forum.
For heaps of questions which will come up as you build your SL, check all over Ray's sight. There are alot of things there, but you have to search around.
If you want a truly tiny keyboard investigate mounting tactile switches onto a piece of stripboard. (You'll find that Uncle Krunkus always reaches for the stripboard first Laughing

) This is something I'd like to try out soon, when I get around to it. They come in black and white (and lots of other colours!) and can be arranged on the board however you like. Then decide decoded matrix or single bus and wire appropriately.
Also, there's a circuit here,
http://www.hoohahrecords.com/resfreq/modular/patseq/patseq.html
It uses a PIC which is pre-programmed to give the classic 5pin sync signal from a midi input. (The PIC costs about AU$20) This circuit is one I definately want to try when I get a few other things out of the way.
Happy building,
(don't plan too long, get that soldering iron warmed up now!!)
See ya,
Andrew

senkun · Joined: Feb 25, 2009 Posts: 9 Location: TPE

Hey guys,

Sorry to dig up this way old thread. I thought I should just add on to here rather than start another.

As in my other question about cheap simple controllers for a Soundlab, I'm getting fixated on using a ribbon controller (since it's relatively affordable with the Softpots). The other technical threads on ribbons got me all overwhelmed.

So searching high and low I found this thread and I got really hopeful when I read what mosc said;

Uncle Krunkus · Posted: Thu Feb 26, 2009 2:12 pm Post subject:

Connect the "top" of the ribbon controller to your +9V supply
Connect the "bottom" to the -9V supply
Connect the "tap" to one of your CV ins,
and use the manual trigger to gate your envelope

That would be the simplist way.
There are much more elaborate ways of doing it, which you can read all about in Scott Stites's "Softpot Ribbon Controller" thread.

BTW a 100K pot hanging off each end of the ribbon controller (in series) will give you a more control over "where you're at" octave wise.

senkun · Joined: Feb 25, 2009 Posts: 9 Location: TPE

Uncle Krunkus · Posted: Sat Feb 28, 2009 1:07 am Post subject:

Just to help you "dial in" the octaves you want the softpot to cover.
If you only want one, it's better to put it on the -ve side.

senkun · Joined: Feb 25, 2009 Posts: 9 Location: TPE

Actually, I could just connect the ribbon to these controllers right? (I hope)

Ray's Single Buss 1V/Oct or Mini-Controller.

Posted Image, might have been reduced in size. Click Image to view fullscreen.

Posted Image, might have been reduced in size. Click Image to view fullscreen.

If so, would these be the connections of ribbon to controller board?

"top" of the ribbon to controller board "KBTP"
"bottom" to the controller board "GND"
"tap" to the controller board "KBUS"

What do "GLA" and "TLA" on the controller board do? LED anodes to "GND"?

Uncle Krunkus · Posted: Sat Feb 28, 2009 3:15 am Post subject:

I think so,
GLA and TLA aren't used on that board IIRC.