Thursday, 15 May 2014

The Boolean Serge

Testing one of my NLC (NonLinearCircuit) modules with the Morley Serge.
I'm mainly using a 4x4 binary logic module in this video.

Here are a few pics of the setup:
The 4x4 is receiving pulses from the Great Divide & 8-bit Cipher.

And some pics of the Paperface Serge:
These are the filters & reverb. The 4x4 logic module supplies all filter & VCO modulation control voltages.

The oscillator section. There is something very very special about these old VCOs.

The nonlinear circuit (NLC) 4x4 logic module is made up
of 4 identical circuits. Each has a different CMOS chip... which will produce related though different sequences & triggers. These kinds of modules are great for triggering drums.

Suitable ICs for use in these circuits are
4081 AND
4071 OR
4001 NOR
4011 NAND
4077 XNOR
4030 or 4070 XOR

A bit about  Binary & Boolean Logic
Boolean logic was first conceived by George Boole (1816-1864). He was an English mathematician & philosopher.

He is now regarded as one of the founders of the digital computer and indeed of digital electronics itself.
In computer programming Boolean data uses binary code: True / False, on/off, or 0/1. His system
consisted of the three most basic operations: AND, OR, and NOT

With all the AND & OR operations there are 2 inputs and one output.

Firstly, the AND gate:

The AND gate is a basic digital logic gate.
You will only get a output if both inputs are 1 (or "high" or "on" or "yes")
If either or both inputs is 0, then the  output will be zero.

A     B        A and B
0     0             0
0     1             0
1     0             0
1     1             1

The 4081 IC looks like this:
As you can see, it has 4 AND gates that can be used independently or cascaded together.
A four-input AND gate can be configured using the 4081

The OR Gate
The 4071 IC in surface mounted form looks like this.

Here is the pin layout:

Again you can see we have 4 OR gates that can be used independently or cascaded together.The output of this gate will be "high" (1) if any or both of the inputs are "high" (1).
The output of an OR gate goes "low" (0) if and only if both inputs are "low" (0).

A     B     A OR B
0     0            0
0     1            1
1     0            1
1     1            1

The NOT gate is also called an inverter.
It outputs the exact opposite digital signal as what is input.
It's not part of the 4x4 binary module but I'd thought I'd include it for completeness.

1 comment:

  1. Interesting and rich music!

    >>There is something very very special about these old VCOs

    How would you describe it's sound or response or anything you like about them?
    (I assume you mean the first VCO based on LM3900 ic)