The Z knob/CV provides a gate function. When Z goes higher than approximately 2.5V, the gate
goes high and the outputs follow the inputs according to the min/max relationship. When Z goes
below approximately -1.5V, the gate goes low and the outputs are frozen.
When the gate changes state, "LO" or "HI" is displayed to indicate the gate status. After a short
while the display reverts to showing the current algorithm.
A-5 Linear/Exponential Converter
Video
A = ( 2 ^ X ) * scale
B = log2( Y / scale )
Z is Hz/V scale, centred on 1kHz
Parameter Min Max Default Description
0 0 1 0 Type A.
1 0 1 0 Type B.
This algorithm provides a linear-to-exponential converter and an exponential-to-linear converter.
You might use this to interface 1V/octave modules (Eurorack standard) with Hz/V synths (e.g. old
Korg or Yamaha synths), but it could also be useful within Eurorack e.g. to convert an LFO
(commonly with Hz/V pitch control) to a V/octave oscillator, or to convert an exponential FM input
on a VCO into a linear FM input.
Input X is the exponential input; its corresponding linear output is A. Y is the linear input, whose
exponential output is B.
Z sets the scale factor which is common to both conversions. It sets the number of Hz per Volt, with
a range from near zero to about 2kHz. The Yamaha CS-15, for example, uses about 1100Hz/V,
which is about half way on the Z knob here.
The zero Volt point on the exponential scale used is C3 (approximately 130.81Hz).
Parameters 0 & 1 switch their respective outputs to function as gate inverters. (Some old synths e.g.
the Korg MS-20 have a Hz/V pitch input and an inverted gate, compared to the Eurorack norm.)
The output is then 5V/0V for an input gate in excess of 1V.
A-6 Quantizer
Video
A = quantized( X )
B = trigger on note change
Z chooses scale & function of Y
Y = transpose (Z positive) or trigger (Z negative)
Outputs & Receives MIDI
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