Showing posts with label DIY. Show all posts
Showing posts with label DIY. Show all posts

Wednesday, 1 July 2015

NLC JerkOff - Chaos Module - Build notes

This is a really cool chaos module & is super easy to build.  It uses chaotic oscillators based around Jerk Equations. It's a excellent source of CVs - for modulating & controlling filters, VCOs, mixing with envelopes, etc etc

Andrew's build notes for the single Jerkoff module are here:
http://www.sdiy.org/pinky/data/single%20JERKOFF.pdf
Build notes for the double JerkOff are here:
http://www.sdiy.org/pinky/data/DOUBLE%20JERKOFF.pdf

WAMOD - More Notes

Much of the original research & design was done by J. Sprott of the University of Michigan.
You can read his paper (in PDF format) here:
http://sprott.physics.wisc.edu/pubs/paper352.pdf

The circuit consists of two feedback loops. The first involving 3 integrators.
The second uses two integrators and a inverter/diode. (Intergrator's are common to analog computers)
I  understand this is described as a chaotic phase-shift oscillator ... consisting of an inverting amplifier (the 741 opamp??) with its output fed back to its input through a phase-shift network consisting of resistors and capacitors.

Here are some pics of the NonLinearCircuit PCB:
The circuit has 3 outputs: X, Y,  Z and 1 input ‘in’. 
Feeding it gates or triggers should get the output signals to sync with other modules.

Headers first:. Resistors & caps next
Andrew has left this module open to lots of experimentation. Above are the marked caps & resistors.

The rest of the component values are very much up to you to pick. I've decided to use 100K B pots.
It's recommended to use resistors with half the value of the pots.... thus 47K ohms are the closest.

These 3 caps are the ones you choose to set the base frequency. I've picked 1uF.
 The rest of the caps are for decoupling. There are 4 of these. ....any value between 10nf & 100nf is fine. I've used 47nF.

The pots are all 100k Linear.

Time to install the LEDs.
I've placed these on the front panel. These LEDs are the superbright variety though I'm not sure of their exact forward voltage or current so I'm experimenting a bit ....using a 10k resistor for now.
(The LED resistor is marked as RL on the PCB) 

Testing the initial build.

LEDs seem to be working.... haven't burnt out yet. :-)
Decided to leave the LEDs where they are for now. Should have cut the legs longer.




     Useful Links
1. Chaos Theory & Jerk Circuits
2. Mongol/Jerkoff - Youtube Video
---------------------------------------------------------------------------------------------------
Click here to return to the NLC Build Index:
http://djjondent.blogspot.com.au/2015/03/non-linear-circuits-ncl-index.html

Sunday, 28 June 2015

VCS 3 - Putney

Messing around with the old Putney.
She is beautiful to behold and still sounds incredible after all these years.
Some pics of the patch:
I'm sampling during this video to see what I can come up with.
This is the unedited version.
...

 ...

Wednesday, 24 June 2015

555 Resonator Build Notes - NLC (NonLinearCircuits)

This is one of my favourite NLC circuits.
It's very versatile. It can be used as a filter, a VCO, a voltage controlled noise source and a voltage controlled drone module.

The module will oscillate without input (depending on the pot settings).
I like inputting a signal from a VCO which will trigger each 555 IC to create pulses.
These pulses can be manipulated with CV to create complex waveforms.

Andrew's manual for the 555 can be found here:
http://www.sdiy.org/pinky/data/FILTER%20panel%20manual.pdf
And his official build notes are here:
http://www.sdiy.org/pinky/data/Its%20555%20build%20notes.pdf

I have a version of this module in Serge/Banana format.


This build however is for a Eurorack Format module.
First, some pics of the virgin panel & PCB before we begin.


The module takes it's name from the 555 timer IC. This integrated circuit is used in a variety of timer, pulse generation, and oscillator applications. It's a very common IC and is cheap as chips.
The standard 555 package includes 25 transistors, 2 diodes and 15 resistors on a silicon chip installed in an 8-pin mini dual-in-line package (DIP-8) .


There are plenty of great videos on this versitile chip:
https://www.youtube.com/watch?v=tn5-XiB8oJk
https://www.youtube.com/watch?v=stN-ZzHfiO4

Andrew's module uses 5 of these 555s.  If I understand Andrew's schemos correctly,
each is part of an individual one shot circuit (also known as a Monostable Multivibrator).

Pin 1 is grounded.
Pin 2 - The trigger input.(connected to C5 - 1nf cap)
Pin 3 - Output.
Pin 4 - usually connected to + VCC to avoid accidental reset.
Pin 5 - grounded through a capacitor (c3 - 10nF?) to avoid noise problems. (This is the decoupling cap?).
Pin 6 - (threshold) is shorted to pin 7 - both are connected to ground via C6 (10nF cap).
Pin 7 - connected to the pin 6 & the discharge capacitor (not shown in the above schemo) - C6 
           C6's discharge time determines the pulse width.
Pin 8 - connected to the supply VCC.

The output of the 555-Monostable Multivibrator/oneshot remains low until a trigger pulse is applied to pin 2. 

It's probably a good idea to install the headers for these ICs along with the other 3 ICs and power connector first.

The other integrated circuits used in this build are two TL072s & one TL074.
The TL07x series are pretty common Op Amps that you will often find in synthesizers.
The TL 072 is a low noise JFET input Op Amp .....commonly used in filters & audio preamps.
The TL074 is a quad Op Amp.
Each of these 4 operational amplifiers incorporates well matched, high-voltage JFET and bipolar transistors. Each op amp has 1 output & 2 inputs (inverting & non-inverting). Voltage is on pins 4 & 11.

But before I install all these, I'll install the resistors, then caps & trannies

The easy ones first.
10uF electro caps (x7), 1nF (x10) & 10nF polyesters (x5).

Now it's time to install the 'cp' caps & decoupling caps.
 The cp caps & trannies form VC resistors that control the pulse width of the signal from each 555. Andrew has suggested starting with 10nF caps and then experimenting with different values.

Next the decoupling capacitors. As their name implies, they decouple or separate one part of a circuit from another. 555 ICs can be very noisy and these caps absorb some of the noise, reducing the effect one part has on another. There are 15 of these caps.

Andrew has suggested values between 47nF & 100nf. He says that the exact value won't make any difference. Use whatever fits and you have a lot of. "The main point is the 555s have plenty of decoupling, hence the 10uF as they virtually short +V to gnd as they do their thing".

Next, the transistors. These include ten BC 547 & ten BC557.
The BC 547 is a NPN transistor.
The BC 557 is a PNP. The cp capacitors and the transistors form VC resistors that control the pulse width of the signal from each 555.

Install the pots:


And the jacks.
Initial jack connections: Blue = Ground, Black = Out, Brown = In.
Test to see how it sounds as a filter by plugging in a sound source (eg: your Dual VCO).

Now connect the rest of the jacks.

Wow ... looks and sounds great !!!
-----------------------------------------------------------------------------
     Useful Links:
1.  NLC filter panel
2. NLC notes (5 more)
---------------------------------------------------------------------------------------------------
Click here to return to the NLC Build Index:
http://djjondent.blogspot.com.au/2015/03/non-linear-circuits-ncl-index.html

Monday, 22 June 2015

Korg DDD-1 Drum Machine

The Korg DDD-1 hails back from 1986-87.
The good old days when sampling was a dirty 12-bits of zeros & ones.

This a a bargain for $100. Sure it's all beaten up but this makes it a perfect candidate for hacking into
it with my soldering iron. There are plenty on mods on the net.
CircuitBenders will modify yours.


Even without the mods there are 4 expansion slots for external ROM cards
and a RAM card too.


AngelFire produce custom pcb cards for the expansion slots.


The drum sounds include: kicks, snares, toms, rimshot, closed hi hats, open hi hats, ride, crash, claps, cowbell, tambourine and cabasa. The trigger pads are velocity sensitive and the tuning & decay of the sounds can be edited.

There are 6 individual outs plus sampled out.
Midi In/out
-----------------------------------------------------------------------------------------------------------------
For more info on the history of Korg Drum Machines Click Here

Saturday, 20 June 2015

ARP 2500 - The Speed of Life


Some pics of this patch:
The 1027 Sequencer & 1050 mixer
It's patched to provide a 8 step sequence.

Just 3 modules being used here: two filters & a EG. (1047, 1006, 1046)

2 VCOs The 1004T & 1023


Friday, 19 June 2015

The White Desert - Egypt

The White Desert is located 45 km (28 mi) north of the town of Farafra. It has massive chalk rock formations ... the main reason for going there ... apart from the the great sunsets & the fun that is
camping in the desert.


An uplifting and unearthly place. Beautiful wind-carved rock formations shaped in the form of giant mushrooms ... we could be on another planet.

unearthly and beautiful wind-carved rock formations shaped in the form of giant mushrooms - See more at: http://en.egypt.travel/attraction/index/the-white-desert#sthash.EMuMzKKL.dpuf
unearthly and beautiful wind-carved rock formations shaped in the form of giant mushrooms - See more at: http://en.egypt.travel/attraction/index/the-white-desert#sthash.EMuMzKKL.dpuf
These deposits were formed during the Mesozoic era and are part of the ancient Tethys Ocean. They are calcium carbonate (a form of limestone). The Mesozoic Era covers a pretty broad expanse of time (262 - 66 million years ago). So this place was once under the ocean.

Great sunsets ... these pics don't do the place justiice.



We spent one night sleeping under the stars.When the camp fire went out the temp dropped and it was freezing. The water in those bottles is frozen.

A warning to all would be travelers.