6.13 Accumulator
The accumulator function is available in sequencer modes, mono, poly, domino and saga. The accumulator is a tool that triggers a defined step while progressively evolving this steps pitch on each sequencer cycle. This function ‘accumulates’ controlled note value changes each time the accumulator step triggers. Pitch intervals, typically semitones, will therefore be added or subtracted from the previous trigger value for the same step to develop and evolve its note over time. Intervals are based on the scale The option to set a probability or logical condition or fill command as to whether the accumulator is applied at each step iteration is also possible.
Accessing the Global Accumulator Step Limits
The accumulator limits can be applied at a step level, where individual steps can assigned accumulator settings including the upper and lower limits, or at a global level where accumulation limits are set for all steps collectively in the sequence and all other accumulator settings are then applied per step.
![Accessing the Global Accumulator Step Limits diagram: Global - Press [Step] AcmM. Step: Set to step, will allow each step to edit the accumulator settings for each individual step. Trck: Set to track to set the limits globally for the sequence and other accumulator...](../../img/oxi-one-mkii/accumulator/accumulator-002.webp)
![Accessing the Global Accumulator Step Limits diagram: Accessing the Individual Step Accumulator Settings Hold [Pad] + tap [Page] to cycle through to page 3. + Accum 3/3 Stp 2 Amt Acml+ Mode Acml- Trig Acm% +0st Wrap +7st -0st Tap (Knob) of the respective parameter to...](../../img/oxi-one-mkii/accumulator/accumulator-003.webp)
Accumulator Settings & Options
The parameter settings are used to configure the accumulator behavior and how the engine will operate when the step row is triggered at each cycle of the sequencer. Each time the playhead triggers the step the next iteration of parameter change will be applied within the criteria and boundaries set. These settings apply only to accumulation behavior of a step and not the discrete step triggers. While the range is generally stated as 'st', semitones, the actual interval is based on the relationship between notes in the currently active scale. The intervals are therefore based on the scale not strict chromatic semitones If accumulation applied to step column with multiple notes in Poly Mode, the entire column of notes is affected.
| Step Submenu - Extended Parameters Hold a step [Pad] + tap [Shift] or tap [Step] button to latch the global view. | |||
|---|---|---|---|
| Amt Pitch change intervals | Mode Order of accumulation | Acml+ Accumulation upper + limit | Acml- Accumulation lower - limit |
| Defines the pitch interval and +/- direction that the note will change on each trigger. | Sets the direction of travel for the accumulation of notes. | Maximum, upper +ve count limit before the accumulator resets and restarts. | Minimum, lower -ve count limit before the accumulator resets and restarts. |
| Total Count status - indicator only | Trig What is affected | %Mde Mode when condition is false | Acm% Probability & accumulation logic |
| Displays the current position / status in the accumulation count process. Display only. | Accumulation can be applied to only the step, only repeats for the step, or all steps & repeats. | Set to ignore or skip. These set the accumulator behavior when the logic condition is false. | Sets the probability or logic condition that determines if and when accumulator is applied. |
Mode: Options
These diagrams show examples of how a single note value behaves on each sequencer cycle, i.e. each trigger of the note. An alternative for wrap, clip and pendulum exists which follows a similar pattern cycle but adds a level of randomization.
Pendulum. Will follow the natural cycle adding or subtracting notes in Amt intervals and will change direction when an upper or lower limit is reached.
Hold. Notes will accumulate in intervals set by Amt, adding or subtracting to its prior value. Once the Acml+ or Acml- limit is reached, the note will hold at the current pitch and continue through the sequence at this level. Intervals are based on the current scale.
Deconstructing the Accumulator
The examples show the behavior of a single step note when assigned with the accumulator. This refers to the Trig parameter being set to apply to ‘All’ - both notes and repeats (either or both can be set). Only the accumulator step will automatically change its value each time the step is triggered or a step repeat is triggered. The output from this algorithm will add or subtract intervals i.e. semitones, set by the amount, the next time the step is triggered or repeated. The original note value is the reference from which the pitch values will evolve. The function is explained with examples below.
Example
Scale: Dorian Root C2
Trig All
‘All’ applies accumulation to both steps and repeats. If repeats exist on the accumulation step they will also be used in the pitch accumulation count and also to the pitch adjustments applied to the repeats.
Mode Wrap
Notes increment each cycle and at the max limit will wrap and continue at the intervals set by amount. In this example it will wrap from Acml+ through the Acml-
Amount +1st
Increment up 1 interval (scale dependant, e.g. 1 semitone in chromatic scales) per sequence cycle. Range is -24st to +24st with the polarity defining if the notes are added to or subtracted from the previous note. If the value was +3st the increment order would be 0, +3, +6, -1, +2, +5, -2, +1 etc.
Acml+ +7st
Maximum interval limit before wrapping or changing direction if pendulum mode is applied. Range is 0 to +24st.
Acml- -2st
Lower limit interval position. Range is 0 to -24st.
% Mode
%Mode sets the behavior of the accumulation when the accumulator probability logic condition is not met. It evaluates the logic condition and establishes whether to skip the accumulation update but retain and replay the last accumulated note for the sequence cycle or just ignore any accumulated value until the next update cycle.
Ignore, will ignore the accumulation when the probability condition is not met. There is no accumulation applied and the step will play its original value.
