Wednesday, 2 December 2015

NLC Collude - build notes

These are my build notes for the Nonlinearcircuits collude module.
It's an envelope follower and very very high gain amplifier (from 2x to 20x).
...... so it should be very useful to amplify all sorts of signals no matter how weak they are
and produce useful voltage envelopes for your modular.

Andrew's build notes are here:
http://www.sdiy.org/pinky/data/COLLUDE%20v1.pdf

There are eight 100k SMDs in the build. I'm using 0805s.
Andrew has given the option of using SMDs or through the hole for the remaining
resistors.

Some NLC wisdom to inspire your build.
Thank goodness for that!
Datura is a genus of nine species of poisonous vespertine flowering plants belonging to the family Solanaceae.

I'm a bit old fashioned so most of the resistors are through-the-hole. except for the LED resistors.
I'm trying out 470R ones this time. I used 1K in the last project. ... no real method in this... just experimenting.

 Surface mount components first, then the IC & power headers.

Thru hole resistors next.

Trannies, Caps, diodes, etc ... all the through hole stuff.
The ceramic cap in the front is 10pf. The schematics ask for a 12pf.

The 4 pots are all 100K linear. I like to insert the pots and jacks on the PCB first without soldering
then screw on the faceplate.
Once you are satisfied that everything is in the correct position , then solder.

Don't forget to solder the ground tabs

Pop those LEDs in and you're done.


Useful links
+ NLC blog

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You can find more NLC builds here.
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Tuesday, 24 November 2015

NLC - 2 x LFOs - Build notes

These are my build notes for the NonLinearCircuits Dual LFO & difference rectifier (Eurorack version).
It's a easy build as all parts are through the hole.


Andrews build notes are here:
http://www.sdiy.org/pinky/data/WAMOD10%20dual%20LFO.pdf
and his blog notes are here:
http://nonlinearcircuits.blogspot.com.au/2015/03/dual-lfo-with-difference-rectifier.html
Some pics of the virgin PCBs
And the rear.
There are two op-amps used : a TL074 & a TL072




.
 Headers first.


Resistors next.

This LFO uses a combination of integrator & schmitt trigger. It's quite a commonly used combo.

This is a simplified version of Andrew's circuit.
The op-amps "A" & "B" are part of the TL 074. "A" is the non inverting schmitt trigger. "B" is the integrator.
The output of the Schmitt trigger is a square wave. This is fed into the integrator. The output of the integrator is a triangular wave, which is fed back to the Schmitt trigger. Thus first stage drives the second, and the second drives the first..... which came first ???? the chicken or the egg ???

The last part of the module is a diference rectifier which is described by Andrew thus:
"This circuit is a hybrid of two basic op amp ‘building blocks’ .....a difference circuit and a rectifier.
 It takes the triangle waves (from the 2 LFOs) and supplies a signal that is the difference between them"
 http://www.sdiy.org/pinky/data/dif.html

The NLC module uses two standard 1n4148 signal diodes for this rectifier circuit.

"Basically the circuit compares the voltage on the ‘-‘ inputs with the voltages on the ‘+’ inputs. (on the 072 op-amp). The difference between these voltages is fed to the outputs. If the difference is positive  it appears on the ‘+’ output, if the difference is negative it appears on the ‘-‘ output. Again, a great way to mix boring CVs to get something interesting, audio frequency wave - shaping. "



The two electro caps I'm using are rated 25V.
I've used monolithic ceramic capacitors for the two 1uF 105s.
The three 100nF 104s are straight ceramics



I've used 1k 0805 SMDs for the LED resistors. Not really sure of the exact value but they are easy to change if needed.
As it turned out, the 1K resistors seem to work well.


The pots now. I was debating whether to chose two audio 100k pots (for frequency adjustment) and two linear pots for the fine adjustments, but Andrew advised me to use all linear100K pots

I've used scrap resistor wire for the ground connectors


Testing the square & triangle waves.

Lovely !!!

Useful links.
+ Video - VCO using a Schmitt trigger & integrator.
+ Pdx.edu VCO
+ Falstad.com
+ Thomas Henry - The birth of a synth
+ The two amp oscillator
+ Circuits Today
+ What is a schmitt trigger and how it works
+ NLC build notes for the difference rectifier & neuron

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Monday, 23 November 2015

Ugarit - Syria

Some old travel pics of Syria. These date from 1999.
These are scans of positive prints so my apologies for the quality.
Digital photography didn't exist back then.

This is the entrance to the Royal Palace.

Ugarit is just north of Latakia on the Mediterranean coast & I reached the site via taxi.
Built on a headland, the port city traded extensively with Cyprus and the Mycenaean civilization.
It's also known as Ras Shamra

They had close connections to the Hittite Empire & sent tribute to Egypt at times.
I believe this section of Syria hasn't been overrun by ISIS so I hope these ruins still exist.

Many on these remains are Neolithic. Much dates from around 6000BC

The city was first mentioned in a document of nearby Ebla, ca. 1800 BC. Ugarit later passed into the sphere of influence of Egypt, which deeply influenced its art.


The city was destroyed in the Bronze Age. The exact date isn't know though most historians agree it was during the reign of  the last king of Ugarit, Ammurapi, (circa 1215 to 1180 BC).

 Remarkably, there is a letter preserved from this time from King Ammurapi to the King of Alasiya, where the King of Ugarit pleads for help to fight invading "Sea People". The situation sounds desperate.
"My father, behold, the enemy's ships came (here); my cities(?) were burned, and they did evil things in my country. Does not my father know that all my troops and chariots(?) are in the Land of Hatti, and all my ships are in the Land of Lukka?...Thus, the country is abandoned to itself. May my father know it: the seven ships of the enemy that came here inflicted much damage upon us."[6]
Sounds like Ammurapi never got the help he wanted.
Sadly, history repeats...... today the new enemy is ISIS.

The origins of the mysterious "Sea People" have been lost in time. There is a relief of a battle between the Egyptians & the Sea people in Luxor, Egypt. (The Temple of Medinet Habu)

After its destruction in the early 12th century BC, Ugarit's location was forgotten until 1928 when a peasant accidentally opened an old tomb while ploughing a field. 

Most of the excavations were carried out by the archaeologist Claude Schaeffer from the Musée archéologique in Strasbourg in 1929.
The excavations uncovered a royal palace of ninety rooms laid out around eight enclosed courtyards.

During the excavation many 2 libraries (a palace library, a temple library) of  cuneiform clay tablets were discovered. All dated from the last phase of Ugarit, around 1200 BC. 

This priceless collection of documents was written in Sumerian, Hurrian, Akkadian (the language of diplomacy at this time in the ancient Near East), and Ugaritic (a previously unknown language).
There is ongoing debate as to whether the Phoenician or Ugaritic alphabet is the oldest in the world.

The libraries contained diplomatic, legal, economic, administrative, scholastic, literary and religious texts. 


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Sunday, 22 November 2015

CGS 38 - Saw pitch shifter & wave multiplier

These are my build notes for the Cat Girl Synth shifter & wave multiplier.
(CGS 38). A very easy build.

Ken's notes are here:
http://cgs.synth.net/modules/cgs38_saw_pitch_shift.html


And the reverse.

IC headers first.

Resistors, caps,  beads next.

I'm waiting on a few components.
TBC.

Monday, 16 November 2015