All About Staircase
Category: Legacy Docs · Tags: eurorack, expedition, staircase · Posts: 1
#1 — Z0NK0UT · 2019-07-22
Staircase is the result of a few years of thought put into the subject of abstract pattern generation using analog computing techniques. It is a component of several modules designed for the purpose of processing horizontal and vertical ramp waveforms as the core source of
a complex 2D figure or pattern. Staircase can be used in much the same way as a synced horizontal or vertical oscillator when fed a horizontal or vertical ramp as its source, but its applications are much more open ended.
In video synthesis patches using our first generation of modules, it was often difficult to break away from the restriction of horizontal and vertical elements and motions. This was largely due to VCOs being the primary pattern generation source, and VCOs being able to lock to either horizontal or vertical directions only. To generate a 2D pattern, a vertically locked oscillator would modulate a horizontally locked oscillator. Staircase breaks out of this paradigm entirely, since its frequency modulation function is achieved through nonlinear waveshaping. This makes it possible to multiply the frequency of a 2D plane rather than a unidimensional one. By this methodology, one pattern can create another, in endless configurations. This method of using chained full wave rectifiers as frequency doublers was first used by us in the original Video Waveform Generator module, to double the frequency of the triangle oscillator core and enable the generation of a sawtooth/ramp waveshape output. It was used again in the polar-to-cartesian waveshaping portion of the Mapper module. Doorway expands on the concept and grants access to its inner workings in a creatively potent manner.
Staircase is a wideband analog frequency multiplier for video processing and pattern generation. It allows the video synthesist to instantly add greater visual complexity to their patches. It can split an elliptical gradient into a series of concentric rings, solarize an input camera source until the brightness of the signal has wrapped around many times, or perform the simple functions of a VCA, mixer, and sawtooth-to-triangle waveshaper.
- Voltage controlled multiplication of the input frequency up to 32 times.
- Voltage controlled phase with harmonics selection allows 243 different visually rich modulation routings.
- Simultaneous output of three different multiplication frequencies enables the rapid generation of full color patterns.
- All signal and control paths perform at high frequency, video rate modulation speeds.
- AC/DC input coupling switches and inverting level attenuators on voltage control inputs.
- Fine tune control of phase modulation channel allows precise tuning of modulation input amplitudes for use cases in which visually continuous phase scrolling is desired.
Specifications
- Width, 10HP
- Mounting Depth, 32mm
- Power +12V @ 70mA
- Power -12V @ 70mA
User Reference
Videos
Patching Tips
- Staircase is one of the most versatile and exciting modules in our system. Revisit it with any possible input signal you have access to, it is designed to make just about anything more geometrically complex.
- Use Staircase to process horizontal and vertical ramp signals at various points along your shape generation patches, and then use the stage outputs to modulate the shape patch.
- Patch the RGB connections in different orders to achieve variant color palettes.
- Instead of the H+V ramp mix, use external video as the input source to Staircase.
- Apply voltage control to frequency. Alternate ramp generator outputs (from Cortex) and external VCOs make great sources.
- Apply voltage control to phase. Flip the first harmonics switch up as a start point (others centered.) Play with switch settings.
- In a more complex patch, insert Staircase into the signal path before a voltage control input, and use it as a weird VCA (with extra effects!)
- With two Staircase modules, insert another processor in a processing chain between the two. Navigator’s rotation feature is especially interesting in this use-case.
- By patching an output of Staircase to the Pedestal CV input of Prismatic Ray, you can gain access to all of its output waveshape slopes as well as mixing with its internal VCO as a modulator.