BMC052 - Chordizer PCB | Barton Musical Circuits

BMC052 - Chordizer PCB | Barton Musical Circuits


The Barton BMC052 Chordizer uses a single voltage input and outputs quantized chord of voltages when used with 1v/octave VCOs

This is a PCB & Pre-Programmed Microcontroller only suitable for multiple formats.

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Availability:In stock

The goal of the Chordizer was to use a single voltage input and output a quantized chord of voltages when used with 1v/octave VCOs. A voltage is inputted through the IN jack and can be modulated by the AUX jack and it's associated attenuator. The voltage range for the input is 0 to 5V. Offsets to the input voltage are then applied, these offsets are controlled by three pots and can be negative or positive offsets. When the offset voltage is outside of the voltage range of the module, it will be transposed down or up an octave automatically to put it back into the voltage range. The input voltage and the offset voltages are then quantized. The QUANT knob selects what musical scale is used to quantize. Before the voltage is finally output, a slew or portamento is applied, controlled by the SLEW knob. The module is compatible with 12V or 15V systems without making any modifications. It also has capabilities to have voltage controllable chord selection.

Controls -
1.OFFSET knobs – These knobs control the offset of the voltages. They are numbered OFF1, OFF2 and OFF3. When the knob is pointed straight up, no offset is applied. When turned clockwise the offset becomes more positive and when turned counterclockwise, the offset becomes more negative. OFF1 controls the voltage outputted at the OUT2 jack, OFF2 the OUT3 jack and OFF3 the OUT4 jack.
2.AUX knob – This attenuates the voltage inputted at the CV jack which is then mixed with the voltage from the IN jack.
3.CHORD knob – This knob selects the memory bank to use in SAVE or LOAD operations. There are 8 memory banks total. The knob attenuates the input of the CHORD jack, which is normalized to +5V when nothing is plugged into it. When using a 0 to 5V range sequencer to select chords, leave this knob fully clockwise.
4.QUANT knob – This selects what scale is used in quantization. The table below outlines the scales. They are presented in order of least clockwise to most clockwise when rotating the knob.
5.SLEW knob – This knob controls how much the notes slew from one to another.
6.TUNE toggle – When activated this sets all outputs to 1V so oscillators can be tuned together.
7.5ths toggle – When active OUT2 will always be a 5th above the input voltage.
8.Quantize-Then-Offset toggle – When active, the input voltage will be quantized before offsets are applied. This makes so that smaller changes in input voltage do not change the output.
9.SELECT toggle – This toggle controls how the SELECT button and input work. When in the center position it will select a chord at random. When in the up position it will rotate through the saved chords in ascending order and in the down position will rotate in descending order.
10.SAVE button – When pressed this will save the current offsets to the memory bank selected by the CHORD knob.
11.LOAD button – When pressed or when the LOAD input goes high, this will load offsets from the selected memory bank. Adjusting an OFFSET knob will override the loaded offset for that output.
12.SELECT button – When pressed or when the SELECT input goes high, this will load a saved chord using the logic determined by the SELECT toggle.

1. MAIN Input – This is the main input, it is mixed with the AUX input and it's quantized output appears at the OUT1 jack.
2. AUX input – This is an auxiliary input jack. The voltage is attenuated by the AUX jack and then mixed with the MAIN input.
3.TRACK input – This input is normalized to +5V when nothing is plugged in. When this input goes low (voltage is less than 0V) the module will ignore changes from the MAIN and AUX voltages.
4.LOAD input – This initiates a load like hitting the LOAD button.
5.SELECT input – This initiates a select like hitting the SELECT button.

OUTPUTS 1-4. VOLTAGE OUPUTS – The only outputs are the 4 quantized voltage outputs.
OUT1 corresponds to the input,
OUT2 corresponds to the input offset by OFF1,
OUT3 corresponds to the input offset by OFF2 and
OUT4 corresponds to the input offset by OFF3.

More Information
Brand Barton Musical Instruments
Additional Resources Build Guide & BOM