Posted: Mon Feb 11, 2008 4:39 pm Post subject:
Pitch makers
Once we have little cheap digital oscillators we need to make some pitch patterns.
One of the easiest to use is the modulo-n counter. You can get a 4018 chip that does this function. I don't do building any more so I leave it as an excersize for someone to post the way to set the pinouts. Here's a link to the data sheet: http://www.st.com/stonline/books/pdf/docs/2032.pdf
The idea is that you plug in your OSC, or any other signal that is square (digital) into the input and the output is divided by the binary number applied to the 4 control inputs.
There is no need to do anything but wire up the 4018 to the banana jacks.
1 input
4 control inputs
1 output.
That's it. You have a little mellody generator.
What do you do for the inputs. Well that's where a lot of fun comes from. You can plug anything you want into the control inputs. Lets say you have 4 oscillators - plug one into each input.
Or, if you have a binary counter IC, use that to divide down a single oscillator to make a pattern. It's best to use a binary up/down counter.
Here are a couple of G2 patches that work with the free G2 demo program. I made the modulo-n counter using flip-flops and logic gates since the G2 doesn't have a modulo-n counter module. All of the red stuff is the modulo-n counter. In the Lunetta, use the 4018 chip - much easier. Anyhow, the G2 patches are there just to give you an idea what this will sound like. Real Lunettas sound like this though - pretty much.
Using the OSC demo, be sure you change the frequencies of the oscillators so you get a feel as to what is happening. In the binary counter demo, be sure to try repatching the order of the connections from the binary counter. You'll get different patterns.
Mod-n w counter.pch2
Description:
A demo of the modulo-n counter (converter/divider) being controlled by a binary counter. This is something similar to the 4018 chip for use in a Lunetta.
Joined: Nov 27, 2005 Posts: 846 Location: Bristol, UK
Audio files: 1
G2 patch files: 1
Posted: Tue Feb 12, 2008 2:41 am Post subject:
Interesting!
Division is generally much easier than multiplication --- but, I've been reading a bit about using a 4046 PLL and a 4017 divider to multiply signals - haven't tried this properly yet, but.....
Here's the schem::::
(I think its from a book by Marston)
This is exactly the circuit I was looking for, for something else.
This Lunetta forum is bringing out some great ideas! _________________ What makes a space ours, is what we put there, and what we do there.
That freq multiplier looks cool, but a little complicated...
Still, it's in the Lunetta spirit. I'd suggest building the divider first. Once one gets into these things, it turns out that you can really enjoy the simplest circuits. _________________ --Howard
my music and other stuff
did you ever build that multiplier? i have been doing a ton of stuff with the 4046 lately but i myself have been using it with a 4024 between pins 3 and 4.
Yeah, this is related to the other question you posted Loss1234 hey?
I knew I'd seen something else which was a lot more immediate than the description I quoted.
If you used a 4046 with a 4017 in the feedback path you could take an input up in frequency by 2X, 3X, 4X, 5X, etc. which would equal some octaves, but also the 3,5,7,9 are not octaves. Then you could divide back down by 2,3,4,5,6,7,8,9 etc. using another 4017. This way you could get heaps more intervals/ratios.
Don't forget that 4017s can be cascaded with the addition of an AND gate, which would mean more ratios again. For example, you could multiply by 13 and then divide by 12. Would that be 1 semitone up? Maybe not, but you get the idea. Man I wish I had the time to start on my own Lunetta!
BTW The cascading of 4017s can be seen at the bottom of it's datasheet. _________________ What makes a space ours, is what we put there, and what we do there.
bugs
one of the things i am doing a lot now is converting an audio signal to square, uping its frequency with a 4046 and then spitting the divided outs to the control ins of other counters.
Loss, how is this working out for you? Does the 4046 follow your squared-up audio signal pretty well?
I'm gonna breadboard the multiplier circuit too when I get a chance. This is something I've been looking for as well-- I want a multiplier for use in clocking rhythmic audio signals to drive syncable delay effects, and/or other syncable circuits. More less, I'm trying to get the function of a tap-clock that can do triplets, quarter-notes, eighths, etc.
Joined: May 18, 2010 Posts: 308 Location: Oak Park, IL
Audio files: 5
Posted: Wed Jan 05, 2011 10:52 am Post subject:
Subject description: The 4018 Revisited
Mosc, thanks for the info on this ic! Works as described and super simple to implement. Lots of cool sounds depending on what's being fed in. Got to get me a bunch more ! Here's a track recorded live with the Fender FRV-1 reverb pedal. I patched thru my 4040 as well as my 4015 shift register to alter the mood a bit. No editing or other effects used.
Joined: Aug 14, 2005 Posts: 1307 Location: Björkvik, Sweden
Audio files: 2
Posted: Sun Oct 13, 2013 3:14 am Post subject:
bugbrand wrote:
Interesting!
Division is generally much easier than multiplication --- but, I've been reading a bit about using a 4046 PLL and a 4017 divider to multiply signals - haven't tried this properly yet, but.....
Here's the schem::::
(I think its from a book by Marston)
Joined: Nov 25, 2013 Posts: 1 Location: Knoxville, TN
Posted: Thu Dec 05, 2013 12:14 pm Post subject:
I'm starting a Lunetta, was wondering if it was possible to use this divider(or another) circuit to get several intervals from a single wave? I.E. Put in a C and get the rest of the scale...or some of it. So I could get a lot of polyphony from a couple of oscillators. I realize this is kind of what's being discussed in this thread but has a solution arisen?
Thanks. Been lurking for a few weeks and this forum is pretty awesome!
That uses a lot of chips just to get a scale. You could use just a few divisions to get a chord, though: see attached (untested) example. Unfortunately you have to make some pretty big divisions to get the most conventional chords, eg. to get a major third in this way you have to divide by 6561! Also, the tones you get will be several octaves lower than the original signal...
chords.png
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Here's a major chord. Note that you put in an E and get out C E G about six octaves down... perhaps if there were a simple way to multiply by 3, 9, 27, 81 this could be made much easier: you'd put the base signal into a binary counter and take each divisions by 2, 4, 8, 16 into an appropriate multiplication circuit. Have a look at this pythagorean tuning diagram and you'll get the idea.
My method, rather than multiply by powers of three and divide by powers of two, was to divide by powers of three and then divide even further by powers of two. This avoids the problems of multiplying frequencies, but the downside is having to start with a very high frequency which is not at all like what comes out the other end. If you come up with anything be sure to post it!
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