XCent screenshot 1 of 5

The Yamaha DX100 emulation nobody asked for, built exactly the way nobody bothered.

Somewhere in a landfill — or maybe your aunt's basement — there's a Yamaha DX100. It ran on six C batteries (because the DC port has cracked solder joints), had a dot-matrix LCD the size of a postage stamp, and produced FM tones so aggressively digital they looped back around to character. It was not prestigious. It did not care.

XCent is that synth, without the batteries, without the 2.7kg of drity black plastic, and with significantly less explaining to do at airport security.

What makes XCent different from the other FM plugins you already own

  • Emulates the YM2164 OPP chip specifically — not its more famous cousin, not a generic FM engine wearing a costume. The YM2164 has quirks. We kept them.
  • Runs the FM engine at the chip's native 55,930 Hz sample rate, then resamples properly. Because running it at 44.1kHz and calling it authentic is the plugin equivalent of putting a photo of a burger on the box.
  • DAC quantization, aliasing, and a sluggish reconstruction filter are all present and accounted for. This is not a bug section. This is the sound.
  • 192 factory voices sourced straight from the original ROM plus velocity imported from the FB-01.
  • All 8 algorithms, full 8-voice polyphony, and operator-level control for when you've decided this is your personality now.

XCent doesn't try to be a DX7. The DX7 doesn't try to be a DX100. We're all better for it.

All for less than the shipping cost on a broken one from eBay.

Changelog

v0.15.11 — May 17, 2026

Features

  • Anonymous opt-out telemetry + in-plugin issue reporter are now on by default. The kos-worker Cloudflare backend (api.knivesonstrings.com) is live, so the soft-launch gate on XCENT_NETWORK_ENABLED is removed and default builds compile in the full feature: anonymous session events POST to /api/telemetry, the Report-an-Issue button on the About modal pings /api/ping and opens a hosted GitHub-issue form at report.knivesonstrings.com. First launch shows a mandatory privacy slide at the end of the onboarding tour with the option to opt out. Opt-out is also available any time via Settings → Privacy. All telemetry events are keyed by an anonymous per-install UUID with no personal data.
  • macOS uninstaller (uninstall.sh) — DMG now ships an uninstall.sh script that cleanly removes all four plugin bundles (VST3, CLAP, AU, Standalone) and forgets the pkgutil receipts. User data under ~/Documents/KnivesOnStrings/XCent/ (patches, preferences, logs) is preserved by default; --purge wipes it too. Bash 3.2-safe so it runs under the macOS system /bin/bash. Flags: --dry-run (preview), --yes (skip prompts), -h (help). Documented in the in-DMG README.rtf and in Docs/manual/MANUAL.md.

Refactors

  • User preferences consolidated into a single file. Pre-launch cleanup: three storage locations collapsed into one. Before, user preferences were spread across hand-rolled settings.xml (Standalone only, written in dtor only), preferences.settings (PropertiesFile via UserPreferences — telemetry + network keys), and WebView localStorage (xcent-tour-complete, xcent-tooltips-enabled, xcent-default-modern). After: every user-configurable preference lives in Documents/KnivesOnStrings/XCent/preferences.settings under the ui.* namespace, with DAW state still mirroring UI prefs via for in-host persistence.
  • DEFER14 / DEFER17 dependency framing corrected — the S/H LFO mid-LFS slope refinement and the triangle/saw LFO pitch-waveshape residual were both labelled "blocked on DSP23" in TODO.md, but DSP23 closed 2026-05-04 with its four correction tables (opp::kPmsScale, opp::kAmsScale, opp::kArRemap, opp::kFblRemap) already in place — and the May-12 sweeps that filed both DEFER entries were run *with* that correction applied. TODO.md now correctly identifies them as separate divergences outside the scope of DSP23's amplitude/AR/feedback compensation, in the same "likely irreducible without Nuked-OPP internal patching" category as DSP23's documented FBL=6/7 and AR=18–30 chip-level residuals.

v0.15.1-rc2 — May 14, 2026

Fixes

  • Portamento now matches DX100 hardware (DEFER18) — Plugin glide was previously ~2.2× slower than hardware at every portaTime, and engaged under more conditions than the real device. Same-day fix after the 2026-05-14 hardware sweep: rate scaled by 22/10 in FirmwareLogic::computePortaRate and triggering tightened to mono + legato. Post-fix sweep matches hardware to a mean |dGlide| of 21 ms across portaTime 10..75. Trigger behaviour now lines up with hardware: portamento only engages when polyMono=1 AND a previous voice is still held when the new note arrives. portaMode (full-time vs fingered) is preserved for SysEx round-tripping but no longer changes triggering (DX100 treats both modes identically).

v0.15.0-rc2 — May 12, 2026

Fixes

  • TEL1 host_version on Standalone (macOS) — /api/issues was rejecting every form submission with host_version is required. Plugin now sends the OS version (e.g. "macOS 14.5", "Windows 11") via juce::SystemStats::getOperatingSystemName() for both Standalone and DAW contexts — JUCE doesn't expose the host application's version separately, but the OS string is a useful triage signal that is always non-empty.
  • TEL1 worker-thread crash on quit (macOS) — XCent quit unexpectedly SIGSEGV inside objc_autoreleasePoolPop during process teardown. The telemetry worker accumulated Cocoa autorelease objects from each POST into its outer JUCE-managed pool; on shutdown that pool teardown raced with Cocoa finalisation and dereferenced freed memory. Fix wraps each drain + each POST in a scoped JUCE_AUTORELEASEPOOL (releases transient objects per-iteration) and tightens the POST timeout from 5s to 1.5s so the worker can finish in-flight requests before being abandoned by the 2s join window. Same fix applied to IssueReporter::ping().
  • TEL1 session_end lost on clean quit — The telemetry singleton's destructor only ran during C++ static finalisation, by which point the UserPreferences singleton holding install_id had already been torn down. The worker's final drain read an empty install_id and the event silently dropped. Fix adds a PluginProcessor-level instance counter that deterministically calls TelemetryClient::stop() from the last-live-instance destructor — while prefs are still alive — so session_end actually POSTs.
  • Standalone state persistence on macOS — Settings made during a session (theme, scale, displayStyle) were lost on close. Worked on Windows. Two compounding bugs:
  • shutdown() ordering — Our custom XCentStandaloneApp::shutdown() destroyed mainWindow before ever calling savePluginState(), so pluginProperties retained whatever stale filterState was last cached. savePluginState() is only triggered automatically by systemRequestedQuit(), which on macOS doesn't fire when the user clicks the window's red close button (only Cmd+Q routes that way). Windows routes window close through systemRequestedQuit, which is why this never surfaced there. Fix calls savePluginState() explicitly in shutdown() before destruction.
  • Foreign children accumulating in filterState — setStateInformation calls apvts.replaceState(ValueTree::fromXml(...)), which adopted our XCentVoice / XCentRom / Scope / XCentPrefs nodes into the APVTS state tree. Each subsequent save reproduced them via copyState(), then we *appended* a fresh copy on top — duplicates compounded every cycle, and getChildByName returned the oldest stale match on load. Fix scrubs known foreign-child tags from the APVTS XML before re-appending fresh ones; one user's filterState went 8705 bytes → 664 bytes after the fix.

Features

  • HMAC-signed report-form & API URLs — The hosted issue-report form (report.knivesonstrings.com) and the kos-worker API endpoints (/api/ping, /api/telemetry, /api/issues) now require an HMAC-SHA256 signature on every request. The plugin signs each URL with a shared secret compiled in via CMake (XCENT_FEEDBACK_FORM_SECRET); the server recomputes the signature and 302-redirects to www.knivesonstrings.com (form) or returns 401 (API) when it doesn't match. Drive-by visits to the form URL or random curl against the API are no longer enough to reach the endpoints — you have to know the secret. Replay window is ±300 s via a signed ts param. The secret is a spam moat, not a real credential — rotate by bumping the CMake var + worker env in lockstep.
  • MIDI CC11 (Expression) — XCent now responds to CC11 as a multiplicative volume scale on top of CC7. CC11=127 (default) is unity — no effect — and lower values attenuate alongside CC7. Lets you ride expression as a separate automation lane from master volume, the way string libraries and wind controllers expect. Not on the original DX100; this is a plugin extension. The routing target will become configurable in a future release (DEFER13: volume / TL bias / off).
  • macOS installer (DIST2) — Signed .pkg installer wrapped in a .dmg with embedded README, licence, and auto-generated manual PDF. Welcome / licence screens included; installs VST3, CLAP, AU, and the Standalone app to the standard ~/Library/Audio/Plug-Ins/ paths. clear-quarantine.sh helper ships alongside for users who download the raw plugin folders rather than running the installer — strips Gatekeeper quarantine attributes and auto-refreshes the AU cache.
  • TX81Z output stage (DEFER6, Phase A) — Added a TX81ZOutputStage implementing the YM3012 / DX21–DX27–TX81Z analog output path alongside the existing DX100 stage. Output-stage selector lives in Settings → Sound, feature-flagged off until hardware calibration completes.

Fixes

  • Bank/slot vs VCED state desync (UI39) — When you save a project, edit the patch bank externally (e.g. SysEx import that overwrites a slot), then reopen the project, the LCD used to claim the slot was unchanged even though the actual sound came from the saved snapshot. Restore now compares the saved voice against the bank's current contents at the same slot and shows the modified-indicator when they differ — so you can see at a glance that what you're hearing isn't what the slot label says, and use Recall to reload the slot's current contents if you want to.

v0.14.0-rc1 — May 9, 2026

Features

  • First-run onboarding tour (UI43) — Spotlight overlay walks new users through Modes, Operators, parameter editing, Modern view, Func mode, and the Patch browser. Dismissed permanently after first run; re-runnable any time from Settings → Appearance → Onboarding.
  • Parameter button hover tooltips — Edit/Func grid buttons show the full parameter name + range after a 500 ms hover. Toggle in Settings → Appearance → Input. Works for the EZ panel knobs and sliders too.
  • Default to Modern view — New setting (Settings → Appearance → Input) makes Edit mode automatically open Modern view (formerly "EZ mode").
  • Settings layout reflow — Appearance tab uses a two-column layout; window scale, skin, and display colour on the left, scope/indicator/input/onboarding on the right.
  • Terminology — UI labels now refer to "Modern view" instead of "EZ mode".

Fixes

  • Floating UI off-screen at non-100% UI scale (root-cause fix) — Tooltips, right-click context menus, copy-to-operator menus, and the tag picker were drifting / clipping off-screen at any UI scale other than 100%. The plugin root has transform: scale() for the user UI-scale setting, which makes it the containing block for position: fixed descendants — viewport-space coords from getBoundingClientRect() and mouse events were being re-scaled by the transform. Symptom previously patched twice with viewport clamping; this release fixes the underlying cause by portaling all floating elements to document.body.
  • LCD modified-indicator case flip on first edit (UI42) — Two bugs: markEditBufferDirty() was inside the if (msg.param) guard in PARAM_UPDATE handler, skipping the call when no param selected; and padString in DotMatrixLcd called .toUpperCase() on every string, hiding E→e.
  • AMS ON LCD display — Renamed AMS ON column to AM=, fixed ampModSens flag wiring.
  • Inter font + contrast pass on patch browser.
  • Manual link — /xcent/manual redirect target.

Known issues / RC scope

  • v1 launch blockers UI39 (bank/slot vs VCED desync), DIST2 (macOS installer), DIST5 (Windows EV signing), and BUG1 (rapid-note clicking, deferred) remain open and are tracked toward v1.0 (see Docs/v1-requirements.md).

v0.12.7 — May 7, 2026

Fixes

  • DSP28 — Breath Controller EG bias formula corrected. The BC EG bias (breath controller → operator volume) was inverted and missing from the note-on path, so patches using breath control (B10 BC1Trumpet, C18 Sax, C19 BC1 Hrmnca) produced flat volume regardless of CC2. Formula polarity fixed: biasAmount = (127 − CC2) × egBiasSens × bcEgBias / 2540. Low CC2 now adds attenuation (as on hardware); CC2 = 127 yields no extra attenuation. Bias now applied at note-on time (applyVoiceToChannel) in addition to the live CC2 handler, so notes triggered before CC2 arrives are weighted correctly. Divisor 2540 calibrated to hardware B10 measurement (20 TL units range for egBiasSens = 4, bcEgBias = 99). Plugin BC curve shape matches hardware; a ~3 dB systematic offset across all CC2 values is the same calibration gap seen in non-BC patches and is not BC-specific.
  • Garbled log output on Windows. Debug log lines were garbled because juce::String::formatted routes through _vsnwprintf and interprets %s arguments as wchar_t*. Each pair of ASCII bytes was encoded as a UTF-16LE codepoint and then re-encoded as 3-byte UTF-8, producing unreadable log files. Fixed by replacing all macro-level string formatting with snprintf (narrow printf), which handles %s correctly on all platforms. Log files from v0.12.7 onward are plain readable ASCII/UTF-8.
  • WebView resource URL — Nuendo / plugin-guard environments. In Steinberg's VST3 plugin-guard subprocess (Nuendo 15, Cubase 15), JUCE passes the full URL including scheme and host (xcent://xcent.localhost/index.html) to the resource provider callback rather than just the path. The resource table lookup failed to find any match, producing a blank white screen. Fixed by stripping the scheme + host prefix before the table lookup. The UI now loads correctly in plugin-guard hosts.

v0.12.6 — May 5, 2026

Features

  • Configurable WebView2 cache location. New environment variable XCENT_WEBVIEW2_DATA. If set to an absolute path, the plugin uses that directory as the WebView2 user-data folder instead of the default %LocalAppData%\KnivesOnStrings\XCent\WebView2. Workaround for sandboxed hosts that don't permit LOCALAPPDATA writes — set the env var to a path the host *can* write to (the plugin install directory, a Documents subfolder, etc.) and reopen.

Fixes

  • Stripped-runtime detection. WebView2Detector::isWebView2AvailableForJuce() now cross-checks the registry version against the actual presence of msedgewebview2.exe on disk. Some "audio optimization" scripts (Atlas OS, BlackViper variants, Win11Debloat) strip the WebView2 runtime files but leave the EdgeUpdate registry key behind. Previously we trusted the registry, constructed the WebView, and got a white screen when the loader couldn't find the binary. The new check searches the two standard install bases (%ProgramFiles(x86)%\Microsoft\EdgeWebView and %LocalAppData%\Microsoft\EdgeWebView) for the version the registry reports; if it's not there, the runtime is treated as missing and the WebView2 missing panel is shown — same as a fresh install with no runtime at all. Either way the user gets the "install WebView2" prompt with a working button.
  • Host process diagnostics + write probe. HostDiagnostics.cpp now runs three checks in the editor constructor:
  • Host process info. Logs the host EXE name, full path, and Windows token integrity level (Untrusted/Low/Medium/High/System). Detects AppContainer sandboxes used by FL Studio and some Cubase configurations.
  • WebView2 runtime cross-check. Logs the registry-reported version *and* the resolved on-disk path to msedgewebview2.exe. If the path is empty while the version is non-empty, an explicit STALE REGISTRY error line is emitted naming the likely culprit scripts.
  • User-data-folder write probe. Before the WebView is even constructed, attempt to create + delete a probe file in the cache folder. If the host sandbox is blocking writes (Cubase VST3 sandbox, restricted ACL on LOCALAPPDATA), the editor skips the WebView entirely and shows the failure panel with the specific Win32 error string and an environment-variable workaround.

v0.12.5 — May 5, 2026

Features

  • Native fallback panel when the UI fails to load. Beta-tester report: a fresh v0.12.1 install came up to a blank white screen inside the VST3 host. Previous behaviour was diagnostic-blind — if the WebView2 runtime initialised but the page failed to render (cache corruption, JS module load failure, sandbox/AV interference), the editor showed an empty white component with no signal that anything had gone wrong. This release adds two layers of detection on top of the existing WebView2MissingPanel (which still catches "runtime not installed at all"):
  • pageLoadHadNetworkError hook. XCentWebBrowser is now a WebBrowserComponent subclass that overrides pageLoadHadNetworkError and pageFinishedLoading, both of which log to xcent.log and feed back to the editor. A network-level error swaps the WebView for a native diagnostic panel immediately with the platform-specific error string.
  • 8-second UI_READY watchdog. A one-shot juce::Timer arms after goToURL. If React's UI_READY message hasn't arrived by the time it fires (typical legitimate load is 1–3 s), the editor falls back to the same diagnostic panel. UI_READY arriving first cancels the watchdog. Network errors arriving first also cancel it.
  • Diagnostic panel content. The new WebViewLoadFailedPanel shows failure reason (network error string, or "did not signal ready within Ns"), detected WebView2 runtime version, path to xcent.log, path to the WebView2 cache folder, an "Open log folder" button (shells to the logs directory so testers can grab the file), and a "Clear WebView2 cache" button (deletes the user-data folder so the next plugin instantiation rebuilds it from scratch — fixes ~half of stale-state white-screen reports on similar JUCE WebView plugins).
  • Installer: WebView2 cache wipe on install and uninstall. xcent-installer.nsi now removes %LOCALAPPDATA%\KnivesOnStrings\XCent\WebView2 in the Finalize section of the install and at the end of the uninstall. Reinstalling a new version always starts with a fresh WebView2 cache, which eliminates "old cache poisons new build" as a class of failure mode without the user having to do anything manually. User data at Documents\KnivesOnStrings\XCent (patches, prefs, logs) is still preserved across install/uninstall as before.

v0.12.4 — May 3, 2026

Fixes

  • CPU meter now shows 0% at idle. The CPU meter was showing 30–50% with no notes playing. Root cause: any MIDI input (active sensing, clock, or other real-time messages from a connected keyboard) kept midiMessages non-empty every block, which prevented the idle flag from engaging and left Nuked-OPM running on silence. Fixed with an early fast-path exit in processBlock: if the engine was idle last block, the FIFO is empty, and there is no pending voice change, we store 0.0f to the CPU meter and return immediately — skipping APVTS reads, MIDI iteration, SysEx handling, renderBlock, gain apply, and peak metering. The meter now reads 0% at idle and only lights up during active synthesis.

v0.12.3 — May 3, 2026

Features

  • Mouse wheel parameter speed +50%. useWheelControl previously stepped 1 unit per tick. Now uses a fractional accumulator with a 1.5 step/tick base: the accumulator alternates 1–2–1–2 (average 1.5), giving exactly 50% faster scrolling without changing coarse-mode (Ctrl+wheel). Accumulator resets on direction reversal and on gesture end.

Fixes

  • Undo/redo depth fixed. undo() and redo() both send a VOICE_RESTORE to C++, which echoes back VOICE_LOADED. The echo called setVoiceParams() which clears both the undo and redo stacks as a side effect — so after the first undo the remaining history and all redo state was wiped. Fixed by adding setVoiceParamsKeepHistory() to the store (syncs voiceParams only, no stack side-effect) and using it in the VOICE_RESTORE echo path in App.jsx. Undo stack depth is now the full 50-entry limit; redo works correctly across multiple undo steps.
  • LCD prefix: patch-level params no longer show operator mask. In EDIT mode, operator-scoped params (AR, D1R, OUT, etc.) still display E1111 OUT=23 OP1 — the mask shows which operators are active. Patch-level params (ALG, FBL, PMD, pitchBend, transpose, etc.) now display E ALG=1 instead of E1111 ALG=1. The 4-char operator mask was unused for these params and caused long names like PBend Range=12 to be truncated.

v0.12.2 — May 3, 2026

Features

  • UI37: mouse wheel for pitch-bend and mod-wheel controls. Both on-screen wheels now respond to mouse scroll when the global Settings → Mouse Wheel toggle is on.
  • BEND: ±5% of range per tick (Ctrl/⌘ = ±10%), springs back to center (8192) automatically after 350 ms of quiet — matching the hardware pitch-wheel spring-return behaviour.
  • MOD: ±1 per tick (Ctrl/⌘ = coarse), holds the scrolled value.

Fixes

  • DSP24-KVS: ROM-extracted KVS velocity → TL offset table. The per-operator key-velocity-sensitivity (KVS) attenuation previously used a quadratic approximation. At KVS=5, vel=16, the approximation over-attenuated by ~9 dB vs hardware. The error grew at low velocities with high KVS settings (up to −10 dB at vel=16). Velocity → TL is now a direct ROM-extracted lookup table sweeping all 128 MIDI velocities × 8 KVS levels through the actual DX100 ROM firmware. ROM values are monotonically non-increasing with velocity; KVS=0 is all zeros; KVS=7 at vel=1 = 78 TL units (≈46 dB attenuation). Zero regressions on 552-case test suite.
  • UI42 partial — two bugs fixed + diagnostic added. Two confirmed bugs causing erroneous dirty-flag state were fixed: 1. VOICE_RESTORE echo reset dirty after undo. The undo path sent VOICE_RESTORE to C++, which echoed back VOICE_LOADED with no bank/slot/name. App.jsx called setPatchLoaded(undefined, …) which set editBufferDirty=false — immediately undoing the dirty flag set by the undo action itself. Fix: VOICE_LOADED handler now guards setPatchLoaded behind msg.bank != null. 2. masterTune PARAM_UPDATE marked dirty on every patch load. After each notifyVoiceLoaded, C++ sent a separate PARAM_UPDATE for masterTune, which triggered markEditBufferDirty() → dirty=true immediately after loading any patch or navigating prev/next. Fix: masterTune now travels as a field in the VOICE_LOADED payload and is applied via setVoiceParam without calling markEditBufferDirty.
  • UI39: SysEx-loaded voice display fix (partial). Two parts of the bank/slot desync were addressed: 1. Display fallback for slot-less voices. When a voice is loaded with no bank/slot origin (SysEx receive, Init Voice), the LCD PLAY mode now shows P instead of the confusing P: format (e.g. PSysEx:BRASSCOMP). 2. State preservation on SysEx receive. When a single-voice SysEx is received via MIDI, currentBank_/currentSlot_ are now set to "SysEx"/-1 so getStateInformation saves the correct origin. Previously, the saved bank/slot pointed to whatever was loaded before the SysEx arrived, causing the wrong patch to be shown on project restore.
  • CPU display. VuMeter rAF loop now self-terminates when the meter fully decays to zero (was running at 60 fps continuously even at idle). CPU meter EMA decay is faster (α=0.06 vs 0.033) — stale high readings clear in ~0.5 s instead of ~1 s. Attack still fast (α=0.3) for spikes.

v0.12.0 — April 29, 2026

Fixes

  • Pitch EG level scaling (DSP13). Level-to-pitch conversion now uses the ROM-extracted kPegLevelScale[100] table (DX21 ROM $DCDD) instead of the previous (level-50)*5*3 approximation. Internally represented as a 16-bit value centered at 0x3000 (±48 semitones full swing). Level 50 = zero offset; Level 99 = +48 semitones; Level 0 = −48 semitones.
  • Pitch EG rate stepping (DSP12). Per-firmware-model PEG:
  • DX100 / FB01: instant snap to L1 at note-on, no subsequent movement.
  • DX21 / TX81Z / DX11: ROM rate-accumulator algorithm — step = lfoDelayRate[99−R] per CMI tick (~13.7 Hz). Phase machine: attack1 (→L1) → attack2 (→L2) → sustain-hold → release (→L3) → idle. Note-off triggers release. Instant sentinel (R=99) snaps and advances phase in a single tick.

v0.11.10 — April 27, 2026

Features

  • Hardware-comparison pipeline (new). Tooling shipped this version for the DSP17 family of investigations (reusable for DSP12/DSP13 PEG extraction next).

Fixes

  • +3 dB analog-stage calibration (DSP17 / DSP21). Hardware-comparison data showed the plugin was systematically ~3 dB quieter than the DX100 line-out across all 8 algorithms after segmentation contamination was ruled out. Adopted kPassbandGainDb = +2.5 dB net, then refactored the constant into two semantically-distinct components:
  • kFilterPassbandGainDb = -0.5 dB — IC12 active LPF passband loss, rigorously derived from the dual-input differential drive topology: Vout/Vnode_A = (Z_C3 - Z_C2) / (R + Z_C3) with R = R2 = R3 = 2.2 kΩ. Yields ≈-0.6 to -2.7 dB across audio (low-frequency limit modeled as flat -0.5 dB). The previous "R1/(R2∥R3) divider" framing in the spec doc was a hand-wave (op-amp inputs are high-Z so they don't load that way) — magnitude was right by coincidence.
  • kOutputCalibrationDb = +3.0 dB — empirical calibration to match the absolute level of the hardware reference recordings. Not attributable to a single schematic stage: IC21 output driver (+14.7 dB inverting amp), VR3 volume pot, and audio-interface input gain during reference capture are all unmodeled and collapsed into the implicit "DAC max → host ±1.0" mapping. Documented as such.
  • ROM-extracted PMD/AMD scaling tables (DSP19a). A diagnostic test revealed that the LFO-depth path was writing voice PMD/AMD (VCED range 0–99) directly to the YM2164 register. The actual DX100 firmware applies a non-trivial ROM-extracted scaling. Tables extracted by sweeping the actual DX100 v1.1 ROM in the HD6303 emulator:
  • PMD: approximately linear (~127/99 expansion). voice 80 → reg 102. voice 99 → reg 127 (full scale).
  • AMD: dramatically non-linear with an exponential top end. voice 50 → reg 16 (32% of register range); voice 80 → reg 37 (29%); voice 90 → reg 54 (60%); voice 99 → reg 127 (full scale).
  • DSP18 patch 102 KC — verified, no regression. User-supplied hardware capture for patch 102 (codebase A02 Uprt Piano) across MIDI 57–63 (A3..D#4). Per-note H1/H2/H3/centroid + pitch analysis: plugin tracks hardware within ±1 dB on every harmonic and ±0.04 cents on pitch across the captured range. The KC break the user observed in v0.11.6 is not present in current code — almost certainly closed by DSP19a + the +3 dB calibration. Status: verified in narrow range; wider chromatic capture would formally close.

Known issues (carried over from v0.11.9)

  • UI42 P1 v1 blocker — modified-indicator case flip never fires on user edit. See v0.11.9 entry below and Docs/TODO.md UI42 for full diagnostic context.

v0.11.9 — April 25, 2026

Features

  • Play-mode LCD mode letter (clean state only — see UI42 for dirty). The LCD now prepends P to the patch identifier in PLAY mode, matching the DX100 hardware convention (was previously no leading letter).
  • Modified Indicator setting. Settings → Appearance → Modified Indicator. Two styles, both visible and persistable:
  • DX Mode (default) — hardware-style: when the dirty bit fires, the mode letter is intended to lowercase (P/p, E/e, F static).
  • Standard (\*) — replaces the would-be-lowercase letter with *. Clean-state display is identical to DX Mode.
  • voiceModified persistence. The voice-modified flag now survives DAW project save/reload and Standalone restart via an atomic on PluginProcessor serialised alongside the voice blob, with bidirectional WebView event sync.

Fixes

  • Edit-mode patch-level params (ALG, FBL, LFO\*, PMD, AMD, pitchBend, transpose) were incorrectly showing an F prefix on the LCD — they're voice params, not system params, and now correctly get E1111 (edit-mode prefix with op-mask).
  • FUNC mode fallback (no param selected) was rendering E1111 FUNC MODE. Now correctly shows a static F FUNC MODE.

v0.11.8 — April 21, 2026

Features

  • UI36 — Mouse wheel adjusts EZ-mode parameters. Scroll over any EZ-mode knob, slider, or the main output knob to step its value. Modifier keys scale the step:
  • Default wheel: one integer step (or 0.02 for the normalized output knob).
  • Ctrl / ⌘ + wheel: coarse — ~10% of full range per tick.
  • Shift + wheel: fine — 1/10 of a standard step (for ranges that allow it; integer params stay at 1).
  • TOOL1 — Auto-tagger feature upgrade (v2 rules). The corpus-derived tag rules now use twelve features instead of four. Parameter-rule yield jumped from 0 firing rules in v1 to 5:
  • lead gated to algorithm 2 (conf 0.78 — fires alone)
  • brass gated to algorithm 5 (conf 0.78 — fires alone)
  • organ gated to algorithms 1/2/3 (conf 0.75 — fires alone)
  • perc on algorithms 3/4/5/7 and strings on 2/3/5/6/7 (both fire as secondary signals combined with a name hint)
  • mouseWheelEnabled persisted setting. Joins theme, uiScale, displayStyle, and fb01VelocityMode in the state XML. THEME_STATE emitted on UI_READY now carries both fb01VelocityMode and mouseWheelEnabled so the UI reflects the saved values at load (previously the former was computed but never consumed by the front-end).

Fixes

  • UI35 (final pieces) — ROM banks are read-only, MIDI bulk dumps persist. Two safety gaps in the v0.11 patch model are now closed:
  • ROM read-only everywhere. Backend storePatch, renamePatch, and deletePatch refuse to write bank 100/200/300/400 and log a warning. The browser modal disables the Store button on ROM banks (and on Favorites/Recents), with a tooltip explaining *why* it's disabled. ROM bank rows in the tree carry a 🔒 glyph and "read-only ROM bank" hover tooltip.
  • MIDI VMEM bulk dumps now stick. When a 32-voice bulk dump arrives over MIDI, the audio thread writes it into bank A (as before) *and* sets a deferred pending flag. The editor timer consumes the flag on the message thread, calls persistUserBankToDisk("A") to write the bank out to disk, and pushes a full bank refresh to the UI so the browser's other 23 slot names update, not just slot 0. A log line records the event for diagnostics.

v0.11.7 — April 19, 2026

Features

  • Single-click Windows installer built with NSIS. One executable drops VST3, CLAP, the Standalone, the PDF manual, and CHANGELOG.md into place with a bundled Microsoft Edge WebView2 Runtime fallback for clean machines. Output: build/XCent-Setup-.exe (~6 MB with LZMA /SOLID compression).
  • Installer behaviour.
  • Welcome → License → Install Scope → Components → Install → Finish wizard flow.
  • Per-machine (default) or per-user radio choice on a dedicated page after the license:
  • Per-machine: %CommonProgramW6432%\VST3, %CommonProgramW6432%\CLAP, %ProgramFiles%\Knives On Strings\XCent\
  • Per-user: %LOCALAPPDATA%\Programs\Common\VST3, %LOCALAPPDATA%\Programs\Common\CLAP, %LOCALAPPDATA%\Programs\Knives On Strings\XCent\
  • WebView2 detection mirrors the in-plugin detection logic — same GUID, same registry key, same minimum major version (109). Bundled Evergreen Bootstrapper only runs when the runtime is missing or too old; already-installed users see a no-op.
  • Start Menu shortcuts for the Standalone, the PDF manual, and the uninstaller (when the relevant components are selected).
  • Uninstaller registered at the correct HKLM/HKCU Add/Remove Programs key based on install scope. User data at Documents/KnivesOnStrings/XCent/ is intentionally preserved on uninstall.
  • Documentation regeneration. The user manual is regenerated as XCent-Manual.pdf at installer build time via marked + Microsoft Edge headless (--print-to-pdf). No pandoc or Puppeteer required. The changelog is copied from the repo at build time so it always tracks the released version.

v0.11.6 — April 21, 2026

Fixes

  • Blank-UI problem on clean Windows installs. When Microsoft Edge WebView2 Runtime is missing or older than Chromium 109 (required for JUCE 8's resource provider interception), the UI would either show "Can't reach this page https://juce.backend" or just stay blank-white. No more — the plugin now detects this at editor construction time and shows a proper fallback panel explaining what's needed, with a one-click button that opens Microsoft's official installer page.

v0.11.5 — April 20, 2026

Features

  • Format picker dialog for SysEx export. The browser's new "Save as SysEx…" action opens a dialog with six target formats:
  • DX100 VCED (single voice) / DX100 VMEM (32-voice bank)
  • DX21 VCED / VMEM (byte-identical to DX100 but labeled as DX21 for clarity — chorusSwitch is meaningful here)
  • TX81Z VCED+ACED (two-message export: ACED first with LM__8976AE header + per-op waveform/fixed-freq/EG-shift fields, then VCED)
  • TX81Z VMEM (32-voice bank with ACED data packed into bytes 73–96 per voice)
  • Least-lossy default. The dialog pre-selects the format that preserves the most data for the voice's hardwareContext.firmware: DX100 voice → DX100 VCED, DX21 → DX21 VCED (keeps chorusSwitch), TX81Z → TX81Z VCED+ACED, DX11 → TX81Z VCED+ACED (lossy, drops PEG), FB01 → DX100 VCED (lossy, drops arVelocitySensitivity).
  • Field-by-field loss warnings. The dialog shows an orange "DATA LOSS WARNING" section listing exactly which fields will be dropped and their current values, or a green "No data loss" confirmation. Detected losses cover: OPZ per-op fields (waveformSelect, fixedFreqEnabled/Range/Fine, egShift) + TX81Z global fields (reverbRate, fcPitch, fcAmplitude, operatorOnOff) when exporting to OPP formats; DX21 fields (chorusSwitch, footVolumeRange) when exporting to TX81Z; arVelocitySensitivity in all hardware formats (FB-01 export not supported, spec doc 10 §Export Matrix).

Known issues

  • TX81Z VCED edge case. The exporter appends operatorOnOff as byte index 93 of the TX81Z VCED payload, making the data 94 bytes rather than the stated 93. Matches observed TX81Z hardware transmit behaviour but may fail checksum validation against strict 93-byte-only parsers. If this breaks hardware round-trip in beta testing, we'll move operatorOnOff to travel via ACED or VMEM exclusively.

v0.11.4 — April 20, 2026

Features

  • Internal library is now .xcb instead of .syx. Documents/KnivesOnStrings/XCent/Library/ contains factory-a.xcb…factory-d.xcb and my-sounds.xcb. Preserves all VoiceParams fields (OPZ waveforms, fixed-freq, arVelocitySensitivity, chorusSwitch, hardwareContext) across save/load — the .syx format silently dropped all of these.
  • .syx remains an IMPORT format. SysExLibrary::importFile(path.syx) parses external DX100/DX21/FB-01/TX81Z dumps and stores them internally as .xcb. Hardware interchange still works both directions via the dedicated import/export paths; .syx just isn't used for our own storage anymore.

v0.11.3 — April 20, 2026

Features

  • TX81Z VCED+ACED import. Single-voice TX81Z dumps (ACED supplementary + VCED base, transmitted together) are now parsed into a unified VoiceParams with hardwareContext = OPZ/TX81Z/TX81Z. The ACED data fills in per-operator waveformSelect, fixedFreqEnabled, fixedFreqRange, freqRangeFine, egShift, plus voice-global reverbRate, fcPitch, fcAmplitude.
  • TX81Z VMEM bank import. 4096-byte 32-voice bulk dumps (format 04 10 00, distinct from DX100's 04 20 00) parse all voices with both VCED and packed-ACED fields unpacked per voice. Context auto-set to OPZ/TX81Z/TX81Z.
  • DX11 auto-detection. DX11 uses the same ACED+VCED wire format as TX81Z but actively uses the PEG bytes (87–92). The importer now inspects those bytes: if they're the fixed TX81Z pattern (PR=99, PL=50) or all-zero, context is OPZ/TX81Z/TX81Z; if they look "active" (anything else), context is OPZ/DX11/TX81Z so the firmware-aware PEG behavior kicks in.
  • DX21 auto-detection. DX100 and DX21 share byte-identical VCED (format 03). On import, the parser defaults to DX100 context; if chorusSwitch=1 (VCED byte 64, a DX21-specific feature the DX100 firmware never sets), it promotes to OPP/DX21/DX21.

Known issues

  • TX81Z VMEM byte 73–83 ACED packing is inferred from analysis rather than service-manual page 24 directly. test_tx81z_vmem_aced_fields_extracted verifies self-consistency, but a real-world TX81Z VMEM file from hardware would be the definitive validation.

v0.11.2 — April 20, 2026

Features

  • Compile-time file logger. Gated by the CMake option XCENT_DEBUG_LOGGING (default ON for now; flip to OFF for public shipping). When disabled the macros expand to nothing — zero runtime cost.
  • Log file at %USERPROFILE%\Documents\KnivesOnStrings\XCent\logs\xcent.log. Overwritten on each launch (no rotation yet). Thread-safe via std::mutex. Auto-flushes so a crash doesn't lose recent entries. Silent fallback if the file can't be opened (no plugin crash).

v0.11.1 — April 20, 2026

Fixes

  • Algorithm carrier normalization re-enabled. The DX100 firmware's per-algorithm TL offsets (ALG 4: +8 TL per carrier, ALG 7: +16 TL per carrier, etc., all extracted from ROM) are now applied in all three TL write paths (note-on, live parameter update, CC7 volume change). Factory patches play at much more consistent levels — previously a 4-carrier ALG 7 patch could be ~12 dB louder than a 1-carrier ALG 0 patch. Re-enables a feature the firmware was always trying to implement (192 kHz hardware recordings showed the real DX100 chip doesn't reflect the offsets at its DAC, but the intent was clearly level compensation and consistency wins over strict matching of that quirk).
  • RAM bank tags. Factory tags for patches loaded into RAM banks A/B/C/D now show in the browser. The factory-tags.json had tags for factory voices 96–191 keyed as LIB:factory-a:0..LIB:factory-d:23 (library-view keys), but RAM banks use A:0..D:23. Added 96 alias entries so both key formats resolve to the same tags.
  • INIT VOICE state safety net. If the DAW-saved voice state has the literal name "INIT VOICE" (e.g., the user clicked Init then closed), the plugin now falls back to reloading the saved bank/slot on next launch instead of self-perpetuating the init state. User-edited factory patches keep their original names and are unaffected.
  • Default patch load robustness. setStateInformation now explicitly falls back to bank 100 slot 0 (IvoryEbony) when either attribute is missing from state, and getIntAttribute("slot", 0) (was -1). Covers fresh installs, decode failures, and partial state files.

v0.11.0 — April 20, 2026

Features

  • Unified Voice Format & Per-Voice Hardware Context. XCent's internal voice representation is now the union of all supported 4-op Yamaha synths, not the DX100 format with extras. Every voice carries its own VoiceHardwareContext (engine / firmware / output stage) — so a voice loaded from a TX81Z dump can be run through a DX21 firmware table, a FB-01 output stage, or any mix. Defaults produce original-hardware behavior; model-specific fields sit at inactive defaults on DX100 voices.
  • DX21 Support. Full ROM analysis (tables confirmed byte-identical to DX100), BBD chorus modeled from hardware measurements (0.331 Hz sine LFO, 2.65 ms center delay, ±1.64 ms depth, pseudo-stereo topology), enabled via the chorusSwitch bit in the voice data. New CHORUS toggle button in the UI below the INC/DEC row — click to enable on any patch, red LED indicator.
  • FB-01 Support. SYX bank import extracts arVelocitySensitivity from the D1R byte (bits 6:5) per operator. The exact AR velocity offset formula is reverse-engineered from FB-01 ROM $0F83 — a 4×16 signed offset table applied at note-on to the AR register, preserving KS bits and clamping to [2, 31]. Available on all firmware models, not just FB-01 voices.
  • Native .xcb Bank Format. Binary voice storage with CRC-32 verification and forward compatibility (voice_data_size header field lets old readers skip unknown trailing bytes). Replaces lossy .syx for internal storage — OPZ waveforms, fixed-freq, EG shift, arVelocitySensitivity, hardware context, and chorus state all round-trip cleanly.
  • Firmware Model Extension.
  • FirmwareLogic::setModel() dispatches olToTl, velocityTlOffset, and applyArVelocitySensitivity by model
  • Per-model tables in RomTables.h (dx21::, fb01:: namespaces)
  • DX21 aliases DX100 tables (byte-identical per ROM analysis)
  • TX81Z/DX11 fall back to DX100 until their ROM analysis lands
  • FB-01 AR velocity offset LUT bundled as rom::fb01::arVelocityOffset[4][16]
  • UI.
  • CHORUS toggle button — new engraved box below INC/DEC in the left column, left-aligned. Red LED lights when enabled. Matches the hardware look of the existing OP buttons.
  • ROM patch numbers — Bank 100 slots show 101–124, Bank 200 shows 201–224, etc. User banks (A/B/C/D) keep 1–24.
  • About modal — Replaced the styled "DCENT" text with the XCent SVG logo (same asset as the header bar).
  • Volume knob — Double-click resets to unity gain (0 dB).
  • WebView2 data folder — Moved from Documents to AppData/Local to avoid OneDrive-sync interactions that can block WebView2 init on some Windows setups. Standalone was never affected because it runs as its own process.

Fixes

  • FB-01 bank parser — Corrected test expectation from 48 voices to 24 per SYX dump. Byte math confirms: 6363-byte SYX → 32-byte header + 24 × 131-byte voice records.
  • FB-01 D1R mask — Was & 0x0F (4-bit), now & 0x1F (5-bit). D1R is a 5-bit field; the old mask silently capped it at 15.
  • Tag seeding — TagStore::load() stored empty tag arrays, blocking seedFromFactory from re-seeding. Factory tags now seed correctly on fresh installs AND recover on upgrades from older versions that wrote empty data.
  • VoiceConvert toVar duplicate — Per-operator "ampModSens" key was a dead write duplicating "amsOnOff". Removed.

v0.10.0 — April 19, 2026

Features

  • Patch Browser. Modal with tag-filtered search across all 192 factory voices plus user banks. Double-click to load, right-click for tag picker. Modal focus trap, ARIA-labeled, keyboard accessible (WCAG 2.1 AA).
  • Auto-Tagging. Every factory voice is auto-tagged via auto-tag-rules.json derived from a 6,312-voice FB-01 corpus. Rules score voices by name patterns and parameter thresholds; suggestions cover categories like bass, pad, keys, lead, brass, bell, pluck, percussion, SFX. Users can override any tag via the right-click tag picker.
  • Factory Tag Seeding. Bundled factory-tags.json covers all 192 voices with curated initial tags. Seeds on first run; custom user tags persist in Documents/KnivesOnStrings/XCent/Library/tags.json.
  • UI.
  • TagFilterBar above the browser — chip-style tag filters with AND/OR toggle
  • TagPicker context menu — right-click any patch to edit tags inline
  • Custom tags — users can create their own tags in addition to the factory set

v0.9.14 — April 6, 2026

Features

  • Pitch Bend & Mod Wheel — On-screen pitch bend (spring-loaded, snaps to center) and mod wheel controls, positioned to the left of the on-screen keyboard. Available on all platforms. Pitch bend sends 14-bit MIDI pitch wheel; mod wheel sends CC1.
  • iOS/iPadOS Build Pipeline — Full code signing with Apple Developer Team ID, automatic provisioning, and one-command deploy to device via xcrun devicectl.
  • iOS adaptations.
  • Full-screen auto-scaling — UI automatically scales to fill the iPad/iPhone screen while maintaining aspect ratio. Accounts for keyboard, EZ mode, and orientation changes.
  • Keyboard shown by default — On-screen keyboard visible on launch (no external MIDI keyboard assumed on iOS).
  • Landscape-only orientation — Locked to landscape for optimal synth layout.
  • Background audio — Sound continues when app is backgrounded (via JUCE_BACKGROUND_AUDIO_ENABLED).
  • Custom app icon — XCent FM algorithm logo at all required iOS sizes via custom xcassets.
  • Scale setting hidden — Window scale option removed from iOS Settings (not applicable).

Fixes

  • VU Meter (iOS) — Routed VU level through the central message store instead of a separate event listener, fixing iOS WebKit not dispatching to duplicate __juce__nativeEvent listeners.

v0.9.1 — April 2, 2026

Features

  • FB-01 Velocity Mode — Authentic per-operator velocity sensitivity for all 192 DX100 factory voices, extracted from FB-01 ROM. Replaces the artificial global velocity floor with real FB-01 data. 86% of factory voices now have velocity response (165/192 patches), including classics like IvoryEbony [2,7,0,0], Solid Bass [4,4,4,4], and Elec Grand [7,1,1,0].
  • Velocity Mode setting (Settings → Sound) — Choose between FB-01 (Recommended) for authentic velocity or DX100 Classic for no velocity (original hardware behavior). Default: FB-01 mode enabled. Removed artificial "Global Velocity Sensitivity" (Off/Low/Med/High/Max) — replaced with authentic FB-01 data.

Migration from v0.9.0

  • Old globalVelocitySens setting is discarded
  • New fb01VelocityMode defaults to true (recommended)
  • Factory patches now use authentic FB-01 per-operator KVS when mode is enabled
  • User patches remain unaffected (KVS values preserved as-is)

v0.9.0 — April 1, 2026

Breaking Changes

  • DCent → XCent Rebrand — Plugin renamed to XCent. New logo: striped X with pointed C. All code, UI, docs, and build system updated. DAW projects using DCent plugin will need to reload/replace instances.

Features

  • Global Velocity Sensitivity — Settings → Sound → Velocity Sensitivity (Off/Low/Med/High/Max). Acts as KVS floor for patches lacking per-operator velocity (all DX100 factory patches have KVS=0). Default: Medium (KVS=3). Persists in settings.xml.
  • Display Style Persistence — Matrix Display setting (Stock LCD/OLED/ FB-01 Amber) now persists across restarts via settings.xml (was previously lost).
  • Improved Settings Layout — Theme and Window Scale moved to settings.xml only (removed from DAW state to prevent conflicts). Appearance settings now use two-column layout with no scrolling.
  • UI polish.
  • Stock LCD Display Mode — Default display style is now "Stock LCD" (light gray on dark). OLED and FB-01 Amber modes available in settings.
  • Algorithm/Envelope Display — Algorithm display scaled to 95%, envelope/algo text 150% larger for better readability.
  • Grid Slot Numbers — Match mode button styling (9px bold white).
  • VU Meter Border — Aligned with CPU meter for visual consistency.
  • Default Scale — Changed from 100% to 125%. Added 125% option to settings dropdown.
  • Light Mode Button Text — Uses panel cream color instead of black. Algorithm SVG inverted for proper contrast.
  • Factory Patch on Fresh Start — Plugin now loads factory patch A:0 on first launch instead of INIT VOICE.

Fixes

  • Rapid Note Clicking Eliminated — Fixed phase discontinuities during register writes that caused audible clicks on rapid note-ons (40% of notes in fast arpeggios). NukedEngine now buffers all audio produced during register write clocks (88 clocks per register = ~80 samples per note-on) into a ring buffer. renderOneSample() drains buffered audio first before clocking fresh samples. Matches real hardware behavior where YM2164 produces continuous audio independent of CPU register writes. See Docs/comparison-report-2026-04-01-fast-clicks.md for analysis.

v0.8.4 — March 29, 2026

Bug Fixes

  • Master Tune Display — Parameters like Master Tune now display their actual values (e.g., F M. Tune=0) instead of --. Added getMasterTune() accessor and send Master Tune as PARAM_UPDATE when patches load.
  • EZ Mode Double-Click Reset — Double-clicking knobs/sliders in EZ edit mode now resets to the value from the loaded patch, not init defaults (0). Added loadPointVoiceParams snapshot system.
  • Display Format for Patch-Level Parameters — Patch-level parameters (Master Tune, Pitch Bend Range, etc.) now show F prefix instead of full E1111 operator status. Operator-scoped parameters still show full status (e.g., E1111 F=18.37OP1 vs F PBend Range=12).

Accessibility (WCAG 2.1 AA)

  • Icon Buttons — Settings and About buttons now have aria-label for screen reader accessibility
  • Decorative SVGs — All non-interactive SVG icons marked with aria-hidden="true"
  • Interactive Controls — EZ mode knobs/sliders have proper role="slider" with ARIA value attributes and keyboard focus (tabIndex={0})
  • Modal Focus Traps — All modals (Browser, Settings, About) now trap keyboard focus and cycle Tab navigation correctly. Created useFocusTrap hook.
  • Form Labels — All input fields have associated labels or aria-label attributes. Added .visually-hidden utility class for screen-reader-only labels.
  • Modal Semantics — All modals have role="dialog", aria-modal="true", and proper labeling

Performance

  • CPU Idle Optimization — Plugin now detects when no notes are playing and skips expensive FM engine rendering. CPU usage drops from ~17% idle to <1% idle. Uses 3-second tail period to ensure release envelopes complete naturally. Tail duration matches getTailLengthSeconds() and covers worst-case RR=0 decay (2.57s).

UI Polish

  • About Modal Links — Website link now goes directly to https://knivesonstrings.com/xcent. GitHub link updated to https://github.com/Knives-On-Strings/xcent. "Docs" renamed to "Manual".
  • Version Display — Now correctly shows v0.8.4 (fixed UI package.json from 0.7 to 0.8).

v0.8.0 — March 28, 2026

New Features

  • Light Mode — Full dark/light theme system via CSS custom properties (229 var() usages across 16 components). Toggle in Settings → Appearance → Skin. Persists across sessions.
  • OLED Display Mode — Blue OLED on Black matrix display style. Toggle in Settings → Appearance → Matrix Display. Instant switch, no restart needed.
  • Tabbed Settings Modal — Reorganized into Sound, Appearance, and MIDI/Audio tabs.
  • MIDI Receive Channel — Omni (all) or specific channel 1-16. Persists in DAW session state.
  • Vintage/Modern Engine Toggle — Bypass authentic DX100 analog output stage for a cleaner sound. Settings → Sound → Engine.
  • Recall Edit — FUNC grid button restores voice to its state at last patch load.
  • Init Voice — FUNC grid button resets to init voice (also available in patch browser).
  • CPU Meter — Live CPU load from processBlock timing with EMA smoothing, green/yellow/red color coding, percentage overlay.
  • Window Scale — 50%, 75%, 100%, 150%, 200% options. Persists across sessions.
  • On-Screen Keyboard — Brighter ivory white keys, scaled to fit window (no scroll), shorter profile.

MIDI Implementation (Complete)

  • CC5 — Portamento Time (overrides voice patch value)
  • CC7 — Volume (attenuates carrier operators via TL offset, preserves timbre)
  • CC65 — Portamento Switch (on/off)
  • CC126 — Mono Mode On
  • CC127 — Poly Mode On
  • Full MIDI receive chart now matches DX100 hardware specification.

DSP Accuracy

  • LFO Delay Fix (DSP14) — Completely rewritten two-phase delay model verified against ROM firmware register dumps. Phase 1: countdown of LFD×3 ticks. Phase 2: linear ramp at rate/64 PMD per tick. Previous implementation was ~20x too fast. Matches ROM within ±1 PMD at every sampled tick.
  • Master Tune Fix — Data entry knob and INC/DEC buttons now work correctly with M.TUNE parameter.

Code Quality

  • PluginEditor refactored — 39 event handlers split from one 588-line block into 5 logical methods.
  • PluginProcessor cleanup — ROM firmware state extracted into RomState sub-struct.
  • pluginval — Passes at strictness level 10 (maximum). Factory preset name fix (getProgramName).
  • Build system — scripts/build.sh auto-increments build number. Binary data refresh on every build.

v0.7.1 — March 26, 2026

Critical Fix

  • Operator Frequency Lookup Table — The VCED freq parameter (0-63) was incorrectly decoded using MUL=freq>>2, DT2=freq&3. The DX100 actually uses a sorted ratio lookup table where all 64 MUL×DT2 combinations are ordered by ascending frequency ratio. 53 of 64 freq values mapped to the wrong MUL/DT2 pair, affecting every factory voice that uses freq ≥ 10. Verified against DX100 owner's manual page 34 and hardware front-panel readout. Example: D01 Glocken OP2 was incorrectly at MUL=4 (ratio 4.0) instead of MUL=5 (ratio 5.0), producing wrong odd harmonics (3rd/5th) instead of correct even harmonics (4th/6th).

DSP Accuracy Improvements

  • Output Filter Raised (fc 10600→20000 Hz) — 192 kHz hardware reference recordings show the real DX100 analog filter is nearly transparent below 10 kHz. The previous fc=10600 Hz over-attenuated high harmonics by ~2.5 dB at 8 kHz. At fc=20000 Hz, attenuation is only -1.1 dB at 8 kHz, matching hardware.
  • Carrier Normalization Disabled — The per-algorithm TL offsets (ALG 4: +8, ALG 7: +16) extracted from ROM firmware register dumps were making carrier operators 6-12 dB too quiet. Hardware recordings prove these offsets are NOT applied during normal playback. Levels now match hardware within ±0.3 dB.

Accuracy Results (192 kHz references)

  • D01 Glocken (ALG=4): harmonics within ±0.9 dB, level within ±0.3 dB, decay rate within ±0.5 dB/s
  • D06 Good Vibes (ALG=7): harmonics within ±0.2 dB, level within ±0.1 dB
  • D15 FM SQUARE: harmonics within ±0.2 dB
  • D17 FMSAWTOOTH: harmonics within ±0.3 dB
  • B01 Solid Bass: harmonics within ±1.0 dB
  • No ultrasonic energy above 10 kHz in any hardware recording (aliasing is not a factor)

v0.7.0 — March 25, 2026

New Features

  • ROM Firmware Audio Path (FW2) — The actual DX100 ROM firmware now runs on an HD6303 CPU emulator inside processBlock. The firmware handles all MIDI→YM2164 register translation with 100% firmware accuracy. Runtime toggle between FirmwareLogic (default, no ROM needed) and ROM firmware (authentic, requires ROM file). CPU load ~19% at 48 kHz.
  • ROM Settings UI — Settings modal now includes ROM Firmware section with file browser, status indicator (loaded/missing/invalid), and mode toggle.
  • SysEx Export — Save current voice as single VCED (.syx, 101 bytes) or current bank as 32-voice VMEM (.syx, 4104 bytes). File save dialog via UI.
  • SysEx Import in ROM Mode — Loading a .syx file in ROM firmware mode writes VMEM voice data directly to the emulated NVRAM.
  • Plugin Scanner Detection (COMPAT1) — Skips heavy initialization when loaded by DAW plugin scanners/validators, preventing scan timeouts.

DSP Accuracy Improvements

  • VMEM Byte 45 Packing Fix — Traced firmware's unpack routine at $974B. The actual bit layout is PMS(7:4)|AMS(3:2)|LW(1:0), not what was previously assumed. All 192 factory voices had incorrect PMS and AMS values. Regenerated from SysEx dumps with corrected bit masks. Most voices had PMS too low (e.g., PMS=3 instead of PMS=6).
  • OL→TL Formula Fix — The firmware uses 99 - OL (for OL ≥ 20) plus a 20-entry prefix table (ROM $8C75), NOT the 100-entry lookup table at $B77E. The $B77E table is used only for KS Level combined lookups. This changes the TL value for every note-on.
  • KS Level Formula Fix — Replaced linear (LS * KC) >> 9 with octave-based exponential scaling using per-octave factors [0, 1, 3, 7, 16, 33, 66, 127] extracted from ROM firmware. The adjustment now correctly doubles per octave.
  • ALG Carrier Normalization — The firmware adds a TL offset to carrier operators based on algorithm carrier count: ALG 0-3 (1 carrier) +0, ALG 4 (2 carriers) +8, ALG 5-6 (3 carriers) +13, ALG 7 (4 carriers) +16. Prevents clipping when multiple carriers sum to output.
  • Velocity Sensitivity Curve — Replaced linear approximation with ROM-extracted nonlinear curve. Per-KVS maximum attenuation table [0, 18, 29, 40, 51, 62, 73, 78]. Floor offset max(0, 7-KVS) at maximum velocity. Concave curve shape.
  • ADC Pitch Wheel Centering — Fixed firmware boot leaving pitch wheel at minimum instead of center, causing notes to play 7 semitones low on non-center-transpose voices.
  • Mod Wheel Position Fix — Fixed firmware inverting ADC value 0 to position $FE (full on), causing PMD to be written as 72 instead of 8.

Accuracy Results

  • FirmwareLogic register writes: within ±1 TL of ROM firmware on all tested voices
  • B01 Solid Bass spectral centroid: 1.09x hardware (native rate)
  • C06 S/H Synth spectral centroid: 1.12x hardware (native rate)
  • Remaining gap is from LFO phase/LFSR state differences (inherent, not fixable)

v0.6 — March 21, 2026

  • Full 4-operator FM synthesis via Nuked-OPM (cycle-accurate YM2164)
  • FirmwareLogic MIDI→register translation
  • React + Tailwind CSS WebView UI
  • 192 factory voices across 8 banks
  • SysEx import (VCED + VMEM)
  • Analog output stage (reconstruction filter + DC blocking)
  • Sinc resampling (55930 Hz → host rate)
  • VST3 + CLAP + Standalone formats