Arpeggiator | Europa User Guide |
Even though the arpeggiator diagram is initially intimidating, Europa’s arpeggiator architecture really is simple when broken down into its individual components. The interaction between them can be very simple to extremely complex depending upon the settings and features used. The important thing is to understand at least the basic interaction between the modules even if the entire functionality of the modules is not understood. Regardless, it is still possible to be creative with the arpeggiator! Note that when in SPLIT mode, there are two arpeggiators – lower and upper. The clock is the only component that is shared between the two arpeggiators. The rest of the settings are completely independent.
Arpeggiator architecture
This section describes the arpeggiator’s architecture, systematically, to help make the architecture easier to understand.
Arpeggiator clocking sources
The arpeggiator can be synchronized to one of three different clock sources: MIDI Clock, the internally generated clock, or the external clock input found on the back of the Jupiter 6 (labeled
trigger in on the back of the Jupiter 6). This clock signal is sent to both arpeggiators when in SPLIT mode, or to the upper voice arpeggiator when in whole mode. Upper and lower arpeggiator
sync sources are not independently selectable. The clock sources are a global setting and are saved with the board NVRAM - not in the presets.
MIDI CLOCK
MIDI IN Clock synchronization is a new feature with Europa. It synchronizes at 24 parts per quarter note (per step – assumes no divider or multiplier). Receipt of a MIDI start message will start the arpeggiator back to the beginning of the arpeggiation stepping (more on that later!). MIDI Clock is not transmitted when synchronized to MIDI clock.
INTERNAL CLOCK
Europa’s internal clock is far more accurate than the original Roland code’s clock, and exact BPM speeds are selectable and are accurate within 0.2% (see Figure for the clock rate table). MIDI Clock will be transmitted when set to the internal clock.
EXTERNAL CLOCK
The external clock advances the arpeggiator at a rate of a single step per pulse. MIDI Clock is transmitted at the rate of the external clock pulses * 12. This assumes that the external clock is one pulse per eighth note. MIDI Clock and other arpeggiator clocking features will not behave in a predictable manner if the external clock is not received at a regular interval.
From this point forward, it is assumed that a single clock is equal to one step of the arpeggiator, regardless of the source clock.
The clock signal (blue line at the top of the diagram to the right) is then fed in to each of the arpeggiators. If polyrhythm is disabled, the clock is routed directly to the multiplier/divider. If polyrhythm is enabled, the number of steps between clocks is equal to the number of notes currently held. As an example, if one note is being held, one step will occur per clock. If two notes are being held, two steps will occur per clock, and so on. Regardless of the polyrhythm setting, the clock is routed through the multiplier/divider.
Polyrhythm enable
Polyrhythm
From note
held list
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