Tuesday, 20 February 2018

NLC Eurorack power distroboard.

Some pics of the nonlinearcircuits distroboard.

What is covfefe? The tweet by Donald Trump that baffled the internet ...

 (n.) When you want to say "coverage" but your hands are too fat and small to hit all the letters on your keyboard.

Back to the build.
Notice the noise reducing capacitors.  
These are decoupling capacitors. They filter out unwanted noise from power supplies.
"A decoupling capacitor is a capacitor used to decouple one part of an electrical network (circuit) from another. Noise caused by other circuit elements is shunted through the capacitor, reducing the effect it has on the rest of the circuit". (Wikipedia).

 In a eurorack system, each module shares a common path to the power supply.
So changes in the current drawn by one one module may produce voltage changes large enough to affect the operation of others. The decoupling capacitor works as the module's local energy storage. The capacitor is placed between the power line and ground. It provides a bypass path for transient currents reducing the chance of voltage spikes and fluctuations.

 I used 3.3K for the LED resistors

  the connector:
oo| GATE
oo| CV
oo| +5V
oo| +12V
oo| GND
oo| GND
oo| GND
oo| -12V 



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An good alternative eurorack bus board with filtering that I've built is the Synthrotek one.
http://www.synthrotek.com/products/modular-circuits/noise-filtering-power-distribution-board/




The build notes are here:
http://www.synthrotek.com/kit-assembly-instructions/modular-circuit-assembly-instructions/noise-filtering-power-distribution-board-assembly-instructions/

i ADDED +5V to this PSU using a simple 7805 voltage regulator and two 0.1uF caps.
The value of the caps could be 10uF or 1uF. I used 0.1uF mylar as I had these on hand.
If you decide to use electros, the negative end of the cap (cathode) should contact ground.





Another good alternative Power bus:
The Bastl instruments Juice Bus. This has onboard 5V


You may wish to add other voltages to your circuit. eg: 9V, 3.3V if you are prototyping circuits:
So ideas:



I haven't tested all these circuits, but notice that the input voltage is always higher than the output voltage.
Experiment with the capacitors
Most linear regulator datasheets suggest tantalum capacitors as they have higher ESR.
Remember that electrolytic capacitors (including tantalum) are polarized.
Best to read the datasheet and follow their instructions.



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Tiwanaku - Bolivia

This is a Pre-Columbian archaeological site in western Bolivia.
It was discovered in 1549 by Spanish conquistador Pedro Cieza de León.
It's near Lake Titicata.

 The Gate of the Sun. This megalithic solid stone arch is constructed from a single piece of stone. The weight is estimated to be 10 tons. The inscriptions found on the object are mysterious. They are believed to be either of astronomical and/or astrological significance.
The Gateway is 2.8 metres high and 3.8 metres wide. 
 


The lintel is carved with 48 squares surrounding a central figure. Each square represents a character in the form of winged effigy. There are 32 effigies with human faces and 16 with condors' heads. All look to the central motif: the figure of a man with his head surrounded by 24 linear rays that may represent rays of the sun.
Some historians and archaeologists believe that the central figure represents the “Sun God”, while others have linked it with the Inca god Viracocha.
(Wikipedia).

Most archieologists appear to date the site to around 300BC to AD 300.
The area around Tiwanaku may have been inhabited as early as 1500 BC.


                        Ponce Monolith.

Such statues perhaps represented the race of stone giants which first populated the world in pan-Andean mythology. Gold pins and traces of piant indicate they were once clothed in textiles and decorated with bright colours. The statue is 3.5 metres tall and dates to c. 300 CE.

 The figure holds a kero (qero) or tall beaker in one hand and a staff-like object, perhaps a sceptre or coca snuff tablet, in the other.

Another mega statue.



Kalasasaya, Tiwanaku. This walled compound of sandstone blocks creates a sacred space used for public and religious ceremonies. It measures 130 by 120 metres.   Standing in the precinct is the Ponce Monolith.

 It has stone heads protruding from the interior of its sandstone perimeter walls






Pumapunku.
Kantatallita is one of the most destroyed ruins of Tiwanaku, where we see huge blocks of cut stone in great geometric detail.


Kantatallita Lintel, Tiwanaku, Bolivia

For more travel postcards click here:

Sunday, 11 February 2018

Bindubba sequencer - NLC build notes

This is a wonderful sequencer.
I have one of these in Serge format and can't wait to test the eurorack version.

The colour code for the 4U panel : Blue are inputs. Red are outputs.
This sequencer has two sets of inputs, a CV out, inverted CV out, glide out and 16 gate outs.
There are also two direction inputs to control forward and backward motion, and two reset inputs
Its interesting to have two different clocks. These will form complex patterns.

Here are some pics of the unbuilt Euro panel and PCBs.
The euro version of this sequencer, is designed to be used with the Divide & Conquer clock divider module (Divide and Conquer - build notes), though any two clocks will drive it. It's better if they are random, or running at different speeds.
The Divide & Conq, is also good for modulating the direction.
Something like the Triple Sloths, is good for modulating the horizontal / vertical jumps

The gate outs are useful for triggering drums, envelopes, pinging filters,

Plug modules like The Hypster ( chaos module) into the Slew inputs

Some NLC words of wisdom
Is this a reference to the 1997 film Con Air???? .... Nicolas Cage acted as Cameron Poe, the burdened soldier who just wants to go home. 

I'm using 680 ohm resistors for the LEDs.

I like to install the ICs first.
They are the fiddly bits. CMOS chips used: 4081, 4029, 4052
My vactrols have very variable off resistances....0.9M to 1.2M
I'll probably need to experiment with the caps. i'll stick with the 470nF caps for now as marked on the PCB.




 Protection against plugging in the module backwards. We have all done this once.


Line up the pots .. don't solder yet.

Jacks.



Another one done. :-)


Links:
+ NLC Build notes& BOM
+ NLC wiki - description & usage of the Bin sequencer
+ Bindubba 1 & 3 sequencers with Kilpatrick Phenol
+ NLC blog (old)

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