Grayscale Permutation 18hp 12hp 6hp Variant Turing Machine Voltages expander

Permutation: a random sequencer based on the Turing Machine

Permutation is a set of random sequencers that use a digital shift register to generate unpredictable CV and gate patterns that can be locked into repeating loops. The concept is based on the Turing Machine, an open source module designed by Tom Whitwell.

Permutation retains the core functionality of the Turing Machine while adding new features such as dedicated outputs for each bit of the shift register, CV inputs for all parameters, and an internal bipolar VCA. Locked sequences are also saved across power cycles.

Variant is an expander module based on the original Voltages expander for the Turing Machine. Variant adds two additional bipolar CV outputs (with modulation inputs) that are derived from Permutation's gate sequence.


User Manual Version 1.1 covers all features of Permutation and Variant.

Ordering Info

Shipping costs will be calculated during checkout based on the weight and destination.



Permutation Comparisons

Each version of Permutation has a slightly different feature set. The 6hp version has an assignable CTRL input. Holding the Clear/Write switches down for a few seconds assigns the CV input to Shift, Bits, or Amp (the internal VCA).

Size 18hp 12hp 6hp
Sequence CV output
Inverted sequence CV output
White noise output
Clock output
Gate outputs 16 8 1
Bipolar VCA Assignable
Pause/Clock switches
Clear/Write switches
Clear/Write CV inputs
+12V current draw 48 mA 48 mA 48 mA
-12V current draw 14 mA 14 mA 14 mA


Tag @grayscalemodular on Instagram with your videos and they can be embedded here.