v0.0.7

Multidrive calibrated against recordings of the original's factory presets: decoded knob
positions played on the recordings' notes, and the engine's constants fitted to them. At full the
original is grittier than SubForce was: the second stage (after the ladder) now clips harder (its
gain at full 2.0, was 1.5) and the drive into the ladder goes to 9×, was 8×. About half of what the
fit asked for, as only two sounds settled it. Below about a third of the knob the change is slight.
The factory presets are re-levelled (−16 LUFS, most within ±0.3 dB).

For comparisons like it, tools/demos renders preset files from anywhere (--files), a preset on a
note list (--notes) and jobs on stdin (--serve); build/demos_tune makes the engine's tuning
constants settable for fits (see Building).

v0.0.6

Fixes from a review of 0.0.3–0.0.5 (engine, plugin, tests and docs):

• A bus with Velocity (or another note-time source) on Glide Time or EG Time used the
  previous note's value; now the note's own (Key: the key played, not the one it glides from).
• EG Sync: a sequenced note a hair before a sync unit no longer restarts a few samples in (a
  click with Reset on); MPC starting or stopping re-bases the count instead of restarting.
• MPC's position ran a few samples ahead after every block whose start wasn't on the 8-sample control
  grid (bar-locked busses and EG Sync); now exact.
• A latched envelope now lets go when MPC stops and on all notes off (CC 123), not only on all
  sound off.
• Duo with a droning osc 2 plays as Mono: a second key no longer retriggers.
• Pitch Bend is a bus source: with Bend To Off the wheel does what a bus makes of it (the guide
  promised that; there was no such source).
• The bus rate text updates at once when its rate mode changes (Hi shows ×10).
• Units: a duplicated track no longer shares its original's unit (no two live instances are the
  same unit); a project saved before units is unit 1, the same on every load; the unit reaches the
  engine together with the values it came with.
• The programmable destinations stay within their documented ranges with two busses or the Key
  source on them; per-note Analog offsets follow the knob (0 is ideal at once, not from the next
  note); EG Time moving every step no longer calls libm; a zero rate in a hand-built patch can't make
  NaNs; reset() between control steps no longer counts samples twice.
• DEPTH has its own Control selector (MOD's list left open showed open there too).
• The device trace marks state saves and loads (getChunk, setChunk), to see whether MPC restores
  parameters after a project's state.
• Analog at 0 is 0.0.4's sound bit for bit on the x86 build and within float rounding (−120 dB) on
  the device's fast-math build (0.0.5's notes said "sample for sample" for both).
• Tests: 640 (from 596), tightened where a check could pass with its feature broken.

v0.0.5

• Analog (the knob that was Drift): besides the drift, now everything that makes an analog unit
  sound like one, all of it scaled by the knob and kept small — cycle-to-cycle jitter, a faster
  drift, slightly imperfect shapes (the saw's bow, the square a little off 50%, soft edges, the
  mixer's AC coupling), per-note variation of shape, cutoff and resonance (as many "analog"
  preset packs do), and the unit: every instance its own tuning error, square width, cutoff,
  resonance and envelope times, kept by a project. At 0 the sound is 0.0.4's, sample for sample.
• Factory presets re-levelled (49 of them by 0.1–0.3 dB).
• CPU on the Force: +0.2% of a block with Analog up (Init 2.85%, the heavy patch 3.7%).

v0.0.4

The rest of the original's manual:

• Key Track for the busses (0–200%, the original's LFO KBTRACK): the rate follows the key. In Hi
  range at 100% the FM follows the keys too and stays harmonic.
• Envelopes: an exponential attack (the original's EXP ATTACK, an analog RC curve), Latch
  (the envelope stays as if the key were held: drones, held filter sweeps) and Sync (restarts
  every note value of MPC's tempo while held: gates, rhythmic plucks).
• Osc 2 Keys (the original's KB CTRL): in Duo, oscillator 2 on the highest or the lowest key;
  Mono or Duo, a drone that follows no key (its Freq knob then ±3 octaves).
• Gated glide (Glide: Gated, Legato Gated): the glide moves only while a key is held.
• Bend To: which oscillators the pitch bend moves (both, osc 1, osc 2, off).
• 3 presets that show them: Drone Lead, Harmonic FM, Trance Gate (74 in all).
• Key tracking still pivots on MIDI 60 (MPC's C3); the original's is MIDI 48 (its C3). Moving it
  would brighten every saved sound by its Key Track times an octave, for no other change.
• CPU on the Force: unchanged (Init 2.7%, the heavy patch 3.5% of a block on average).

v0.0.3

Closer to the original's modulation, from its manual, and 14 more presets:

• Beat Freq (OSC tab): oscillator 2 detuned by up to ±3.5 Hz, so it beats at the same rate on
  every note, as the original's BEAT FREQ.

• Hi range for the mod busses (the Rate Mode is now Free, Sync or Hi): 0.5–1000 Hz, worked
  out every sample on pitch, cutoff, wave and volume — audio-rate FM, filter FM and ring modulation,
  as the original's HI RANGE.

• Seven more sources: Sine, Noise (random, the rate its speed), Amp EG, Velocity, Aftertouch, Key
  and Constant (the original's programmable sources).

• Nine more destinations: EG Amount, Key Track, Osc 1 Level, Osc 2 Level, Beat Freq, EG Time
  (both envelopes), FEG Time, AEG Time, Glide Time.

• DEPTH tab: how much the mod wheel, velocity and pressure add to each bus's depth (−100%..+100%,
  the original's MOD WHEEL / VELOCITY / AFTERTOUCH amounts), and a fifth Control, None.

• 3 presets that show them: Beating Bass, Velocity Growl, Ring Lead (71 in all).

• Block sizes no longer change the free-running oscillators' phase across a silence (it differed by
  about 10⁻⁵ of a cycle, inaudible): the sound is now the same sample for sample however MPC splits
  the audio.

• The new parameters are added at the end of the list and the new options at the end of theirs, so
  saved sounds and projects keep their settings and their Q-Link assignments.

• CPU on the Force: unchanged for the existing sounds; both busses in Hi range on top of the heavy
  patch, 4.6% of a block (p99).

• 11 more factory presets in the direction of KVNDRA's melodic house and ambient
  sound: Deep House Bass, Wah Bass, Dark Pulse Bass, Warm Glow Lead, Rising Lead, Pulsing Lead,
  Melancholy Arp, Slow Analog Arp, Endless Steps, Desert Drone, Cinematic Swell.

v0.0.2

The first regular release: the plugin catalog lists it with a download button and its installers offer
it (0.0.1 was a prerelease, its beta channel, which neither does by default).

• 2 dB louder, level with MPC's own instruments and with PolyForce: the factory presets play at
  −16 LUFS on their demo phrases (was −18), no peak over −1 dBFS (the highest −1.8 dBFS); the
  engine's output is 2 dB up, Init and saved sounds too.
• Release builds: a plain vX.Y.Z tag publishes a regular release, a suffixed one (v0.1.0-beta) a
  prerelease.

v0.0.1

The first public preview.

• Engine: two morphing oscillators (triangle → saw → square → narrow pulse), 32' to 2', hard sync,
  a square sub (−1 or −2 octaves), noise from white through pink to dark, analog drift. A mixer with
  its own feedback loop (thicker, then gritty, then the chaos of an overdriven loop). A nonlinear
  4-pole transistor ladder (6/12/18/24 dB) that self-oscillates past 70% of the resonance knob and
  thins the bass as it rises, with Multidrive (asymmetric, tube-like warmth to hard clipping). Two
  DAHDSR envelopes with a linear attack, velocity, key tracking, reset and a loop through the
  release. Two mod busses (7 sources, free or locked to MPC's tempo; pitch, cutoff and one of 10
  more destinations; mod wheel, aftertouch or velocity). Mono or Duo, note priority, multi or
  single trigger, glide (rate, time or exponential). The whole voice at 2× with a halfband
  decimator.
• 57 factory presets in seven categories (Templates, Bass, Lead, Keys, FX, Sequence, Pad), many
  for melodic techno; all level-matched. User presets, favorites, a browser, Init and Randomize.
• Touchscreen pages (OSC, FILTER, AMP, MOD, BROWSE, KEYS) with a Q-Link set each.
• On the Force: about 2.8% of a block for one held note (3.6% with everything on), measured on
  the device; the ladder runs on NEON.
• Builds: armhf against glibc 2.31 (loads on MPC OS 2.x and 3.x; the pages need 3.x),
  profile-guided, checked with the plugin catalog's catalog_check.py.