Monday, 5 November 2018

LZX - Castle -Modular synth

Some notes before I begin building The Castle.

The Castle synth is different from the Cadet synth which I have recently been putting together.
These modules were designed by  Philip Baljeu of Toronto and were inspired by early digital hardware video synths.
The main difference seems to be that the castle is a system of binary & logic modules.
Binary = on/off or 0/1
It processes 3 bits in parallel....  3 bit data streams
The 3-bits give 8 possible combinations.....Black, Red, Green, Yellow, Blue, Magenta, Cyan, and White.

I'm guessing that these modules will be good for producing computer graphics and pixels ??... but maybe more. I wonder what it will be like when you mix these with the analog Cadet LZX.
It seems that any signal can be used as an input, it doesn't need to be binary logic signals. 
There are 8 modules in this video synthesizer. Everything is through hole, and 4HP

LZX - Castle
00_000 ADC - Analog to digital converter
01_001 DAC - Digital to Analog converter
02_010 Clock VCO
03_011 Shift Register
04_100 Multi Gate
05_101 Quad Gate
06_110 Counter
07_111 Flip flops


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  1. Found this in a facebook post from Philip:

    Castle :
    Anything can be used with vidiot. The castle clock vco needs sync in the power bus however, so youd need a sync generator (cadet sync, or cortex) for that one.

    ADC will take an analog signal and split it in to 3 bits or zones, the separate outputs kind of look like a square wave version of staircase, the first output D0 has 4 lines, d1 has 2, and D2 has 1.

    DAC can take the 3 bits from adc (or anywhere else) and recombine them as an 8 level single stream output. Think of it kind of like a mixer, but it has preset levels for D0, D1, and D2.

    Castle clock vco needs sync on power bus, or you can sync from the front panel jack, but you still need sync. It's a square wave vco, essentially. Prime for clocking logic.

    Shift register is like a 1 bit delay. Data goes in, and moves through the 4 positions based on the clock. D0, through to D3 are the output positions. Each position is one clock cycle delayed from the last.

    Multi logic is 6 logic outputs based on two inputs. Xor, xnor, or, nor, and, Nand. Look up a truth table for those functions. Basically it's a way to combine two stigmatized in interesting ways via binary logic.

    Quad gate is similar to multi gate in that it uses logic gates for binary combination, but it uses a single gate type (ex. Xor. Depends on what you build it with. I suggest xor). There are 2 sets of 2 inputs. A1, b1 and a2, b2. These have they're own outputs, out1, out2. But there are 2 other outputs that are some combination of inputs and outputs to make further interesting combinations.

    Counter will take an oscillator signal from vidiot and give you four divided outputs. /2, /4, /8, /16. And a fifth output that puts out a pulse when the counter has reached the last number in its count.

    Flip flops are like binary sample and holds. There are 3 so you can do a sample and hold type operation on the adc output for example. It had the effect of pixelizing.

    Anything can be used as an input, it doesn't need to be binary logic signals

    1. Thanks for this Chris,
      I'm not on FB much so haven't seen this info.
      Very useful.
      I'll try out some of these later today.
      Cheers Jono

  2. I am just starting to learn. I have no idea about circuits and just want to be able to use this stuff.I also found this (I feel it’s relevant but don’t really understand it):

    “If you want external input video signal in to an lzx system, then yes you would need cortex, memory palace, or cadet sync, or the external video can be genlocked externally and can be input anywhere essentially, with limitations. I'm just referring to input signals on vidiot and Cadet, castle, expedition are video bandwidth inputs and outputs. The inputs on the vidiot can accept wide range voltages, and some of them have attenuators, but the spec of lzx inputs is 1v standard. The inputs with knobs associated have attenuators for euro audio type signals.”