Joined: Feb 02, 2010 Posts: 266 Location: California
Posted: Thu Jun 08, 2017 9:46 pm Post subject:
New CMOS music box - The Melody Oracle
This box uses a 40106 oscillator with it's frequency set by an array of 8 trim pots (tuned to a C major scale here) switched with a 4051.
The output of the oscillator feeds a 4040 divider. The /2 and /4 outputs are used as audio outputs. The highest # divisions are used to feed the three data inputs on the 4051.
The octave divisions /1, /2, /4 are fed to a 4016 for switching them in and out.
I will let you make your guesses as to how the panel works, but I'll say it is switching between the higher number division outputs of the 4040 both for melodic patterns and activation of the different octave registers.
Technically, this is a totally digital synth, except some passive lowpass filtering and summing at the end.
Technically it is also monophonic (there is only one oscillator, which acts both as master audio source and master clock), though with tricks in division it sounds more layered.
The video shows a few patterns set up and then at :30 you see the operation in action. _________________ ∆ A.M.P. ESOTERIC ELECTRONICS ∆
Hi TopTop, that's wonderful! In particular, I like the high number of sensors that you have to modify the melody. The box looks just great. Nice work!
My guess is that you are using Reed switches, but I have no clue how the marbles could be magnetic. Hope that you are going to share the schematic of your music box with us as well.
Are the marbles magnetic? they seem to snap to locations. Anyway, that'd also explain the workings :-) _________________ Jan
also .. could someone please turn down the thermostat a bit.
Joined: Feb 02, 2010 Posts: 266 Location: California
Posted: Fri Jun 09, 2017 12:43 pm Post subject:
Yea, those that guessed magnets were correct, there are about 60 reed switches glued to the bottom of the panel, a little over an inch apart, and along the lines where the colors meet on the panel. The little crystal balls have magnets glued to the bottom of them.
I actually reinvented the reed switch using magnets, wires, and thumbtacks in some early testing I did, before realizing that magnetic switches had been invented over 100 years ago, and that commercially produced ones would probably work more reliably.
The reed switches route divided pulses from one 4040 into six different data buses: three for controlling the melody switching (which go to the data inputs on a 4051, which in turn switches different trim pots in and out to set different frequencies of the oscillator), and three for controlling a 4016, which decides which audio octave divisions are included in the output.
In addition to the various levels of rhythmic division from the 4040, each data bus also has an master "invert" so that you can flip the phase of the whole data stream from the bus to get the opposite pattern, and also a full "on" switch to hold the output high.
As for the schematic request, I didn't draw a schematic, and probably won't (60 switches!). I don't even make PCB layouts anymore, I just wire it up. But I do have a lot of notes in a notebook. I will see if any of them are complete/coherent enough to give a block diagram of what is going on. _________________ ∆ A.M.P. ESOTERIC ELECTRONICS ∆
Joined: Feb 02, 2010 Posts: 266 Location: California
Posted: Fri Jun 09, 2017 1:08 pm Post subject:
A little more to explain what is going on:
If you watch the programming section of the video (from about :30 on), I start by just setting which octaves are being switched in and out. That is the central part of the diamond shapes. You can hear that it is just one note (C), and octave divisions of it being switched in and out rhythmically.
As it moves on, I start placing magnets over the melodic switching sections. Those are arranged in the outer section of the diamonds. They go to the data inputs A,B,C on the 4051, which are weighted with values 1,2,4 and, when combined in different ways, can select outputs 0-7, which as it is tuned now, will play the notes C D E F G A B C.
This is a simplified diagram to show which regions on the panel will add in which numbers. Each region has seven rhythmic divisions which will add that number in and out at different periodic rates. When combined, you get millions (?) of rhythmic options.
Joined: Feb 02, 2010 Posts: 266 Location: California
Posted: Thu Jun 22, 2017 8:34 pm Post subject:
Harmony Oracle
This is a test of a circuit idea I have to automatically accompany the Melody Oracle.
I have added a D9 port to the Melody Oracle and am sending the note and rhythm selection data pulses down a D9 cable.
The "Harmony Oracle" uses 1 & 1/2 CD4013 dual flip flops to capture the three bits being used to select the 8 notes on the 4051 in in the Melody Oracle. What I wanted was something that would play a sustained note when triggered, not necessarily to track the Melody Oracle note-for-note directly. So the 4013's capture the three bits from the Melody Oracle upon clocking, and then hold the 3 bit note state until the next clocking, even though the Melody Oracle itself may continue to play other notes underneath.
So what I have in this test is a 4051 set up basically the same as on the Melody Oracle, but tuned up a 3rd from each note used on the Melody Oracle. So when the root of the scale is played on the Melody Oracle (C), a third is played on the Harmony Oracle (E); when 4th is played on the Melody Oracle (F), a 6th is played on the Harmony Oracle (A), etc...
The Melody Oracle's note data comes down three wires on the D9 cable, and it's rhythm data is sent in parallel. In this video, I have used the "bass" rythm pulses to also trigger the Harmony Oracle's sample and hold. In the finished version, I plan to have it be trigger-able from any of the six data streams coming in the port.
On the Harmony Oracle test circuit, I am using the simple passive "AR" envelope generator and two-diode "VCA" from the thread "A VCA of sorts" here in the Lunettas forum. I am still experimenting with the signal path for the audio aspect of the circuit.
Also included on the D9 cable are the +12V that powers the Melody Oracle, the ground connection, and the master oscillator that clocks the 4040 ripple counter that generate the patterns and melodies on the Melody Oracle. I plan to add one more main part to this "Harmony Oracle" circuit which uses that master clock oscillator divided by 3 to generate a 5th directly tracking the main oscillator, which will also be added optionally as another harmony option into the audio output.
_________________ ∆ A.M.P. ESOTERIC ELECTRONICS ∆ Last edited by Top Top on Fri Jun 23, 2017 2:28 pm; edited 1 time in total
Joined: Feb 02, 2010 Posts: 266 Location: California
Posted: Fri Jun 23, 2017 2:22 pm Post subject:
Here is a diagram of the panel. It shows where the switches are and how it is divided into sections, and what each switch does.
All of the outer parts of the blue sections add together binarily (?) to select between the 8 notes of the scale in according to which outputs are high from the 4040 ripple counter.
So if all outputs in all the outer sections are low, it plays the root (C), if the bottom section has a magnet on one of the switches, it will be alternating between the root note and the 2nd of the scale (0,1 = C,D) at the division rate indicated. If the upper left and the lower outer sections have magnets on the same divisions, the sum of those two is 3 when they are both high (1+2) and it will alternate between the root and a fourth (0,3 = C,F).
And so on. The upper right has a value of 4, so by adding 0,1,2, & 4 in varying combinations, you can get any number 0-7.
When you begin adding those divisions in varying values overlapping, you get more complex arpeggios and melodic patterns.
The borders of the silver/gold sections gate the sound on and off for the three octave divisions of the melody set in the outer parts.
Those simply layer the octaves on top of eachother in the indicated patterns of division.
The "invert" switches take whatever pattern is set with the combination of division switches, and flips the phase of the pattern 180° _________________ ∆ A.M.P. ESOTERIC ELECTRONICS ∆
Joined: Jan 14, 2010 Posts: 5591 Location: Moon Base
Audio files: 705
Posted: Sun Jun 25, 2017 12:49 pm Post subject:
I am starting to see some light at the end of the tunnel but I am not quite out of the woods yet (I have no
idea why there is a tunnel in these woods or is it the other way around ?!), so maybe you can help me out.
- First of all the invert switches; am I correct in assuming they just connect to V+ ?
- Then there is Q5 of the 4040 (/32); in the wiring diagram it is noted as being connected to the switch matrices,
but I don't see it show up anywhere.
- And finally the switches labeled "HOLD ON", how are they connected ? judging by the video I expect they also
just connect to V+. (so INVERT + HOLD would be OFF)
Joined: Jan 14, 2010 Posts: 5591 Location: Moon Base
Audio files: 705
Posted: Mon Jun 26, 2017 6:51 am Post subject:
just had the idea that it might be fun and/or very annoying to build it into a chess board and use magnetic chess pieces.
Some other boardgames could work too I think. A chess board midicontroller might be fun too and probably has been done.
I did come across this:
Joined: Feb 02, 2010 Posts: 266 Location: California
Posted: Mon Jun 26, 2017 1:55 pm Post subject:
PHOBoS wrote:
just had the idea that it might be fun and/or very annoying to build it into a chess board and use magnetic chess pieces.
Some other boardgames could work too I think. A chess board midicontroller might be fun too and probably has been done.
I did come across this:
One of the ideas that originally inspired this was a sort of musical board game. I actually even invented a board game to use, but the plans for it morphed into this synthesizer.
Your questions:
- First of all the invert switches; am I correct in assuming they just connect to V+ ?
Yep.
- Then there is Q5 of the 4040 (/32); in the wiring diagram it is noted as being connected to the switch matrices,
but I don't see it show up anywhere.
Yea, that's right, I ended up omitting it from the panel because I was running out of room and I wasn't particularly interested in the sound that I got from switching at that speed.
- And finally the switches labeled "HOLD ON", how are they connected ? judging by the video I expect they also
just connect to V+. (so INVERT + HOLD would be OFF)
Yes, also to +V. They just add in a solid +12V to the 4070 that is receiving pattern data through the rest of the reed switches.
I also spotted some errors which might only exist in the notes: pin 7 of the 4051 is not connected (should be GND
I think) and the second XOR chip has pins 4 & 5 connected to GND instead of pins 5 & 6.
You are right about that on the 4070! I had actually made a mistake with the in/out pins on the 4070s at first and corrected the gates in use on the diagram but forgot to correct that one not in use. Actually I am now curious whether I wired them correctly because I discovered that error after powering it on for the first time and observing strange behavior (I wired it incorrectly initially). The ones not in use may not be causing any obvious malfunction.
I actually don't know what pin 7 on the 4051 does. I can't recall if I grounded it or not. I believe I thought that was a non-functioning pin. _________________ ∆ A.M.P. ESOTERIC ELECTRONICS ∆
Joined: Jan 14, 2010 Posts: 5591 Location: Moon Base
Audio files: 705
Posted: Mon Jun 26, 2017 2:46 pm Post subject:
great, thanks
pin 7 is the negative voltage for the analog section of the chip, so you can
use it to switch bipolar voltages while using standard positive control signals.
Here's the full schematic decoded from your notes except for the output section.
Melody Oracle.gif
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Joined: Feb 02, 2010 Posts: 266 Location: California
Posted: Sat Jul 15, 2017 12:44 pm Post subject:
Harmony Oracle Update
Here are some new tests of the Harmony Oracle.
Here's what I put in the youtube description:
Breadboard test of a circuit to automatically generate harmonic accompaniment to the a Melody Oracle.
There are two independent voices:
1) A frequency divider using the Melody Oracle master oscillator tone divided by three (via CD4017 counter) to generate a tracked harmonic line an octave & a perfect fifth down.
2) Tunable harmonic note selector using a CD4076 register to sample and hold the incoming three bit note-selection word upon triggering. This word sets the pitch of an oscillator tuned via a set of trim-pots and a CD4051 1-of-8 switch. This allows harmonic notes to be held until the next trigger is received, meaning an independent harmonic phrasing can be generated. In this example the notes of this voice are tuned an octave & a third up, respective to voice 1.
Each voice has its own envelope generator, triggered independently, allowing counterpoint rhythm from each voice.
And here it is with an added XOR ring modulator, with its own independent VCA.
Joined: Feb 02, 2010 Posts: 266 Location: California
Posted: Thu Aug 03, 2017 7:49 pm Post subject:
PHOBoS wrote:
sounds fantastic!
After I clicked on the video and saw your youtube avatar I realized you are the same creator from
a couple of other great machines. I'd love to hear a jam with more of them (if you still have them).
RingMad wrote:
Really nice sound with the "ring mod"! Wonderful creation.
Joined: Feb 02, 2010 Posts: 266 Location: California
Posted: Tue Sep 19, 2017 12:22 pm Post subject:
Recordings
I have been cataloging some of my experiments and improvisations with the Melody Oracle connected to the the next circuit (Harmony Oracle) on the breadboard.
These are little impromptu ramblngs that I record whenever I am messing around with the instruments and come across something that sounds cool to me.
This will get added to as I go on. It's all recorded live with no edits, other than a trim at the head or tail sometimes. _________________ ∆ A.M.P. ESOTERIC ELECTRONICS ∆
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