MMR v1.4.2

MULTIBAND MODULAR RACK v1.4.2
Changes since v1.4.x — incremental update

GUITAR PITCH SHIFTING

• Rebuilt the Pitch Shifter's GUITAR engine to address phasing instead of usable transposition, reported at -2 semitones and 100% wet on guitar DI.
• Added whole-semitone PITCH (-12 to +12) and an adjacent CENTS control (-100 to +100, 0.1-cent steps). CENTS adds to PITCH, allowing +/-13 semitones at the combined extremes.
• Replaced the visible SNAP control with CENTS in GUITAR. Kept independent FORMANT and the existing INPUT, MIX, OUTPUT and POWER controls.
• GUITAR is the default for new instances. LEGACY retains the earlier continuous Pitch/Formant/Snap behaviour for older projects and automation.
• At zero FORMANT, GUITAR naturally transposes the spectrum. MIX remains a dry/wet blend: 100% selects the shifted signal for that rack band; smaller values can blend in a lower octave while retaining the original attack.

PROCESSING AND MONITORING

• New MMR phase-locked spectral-region processing with longer analysis and asymmetric, normalised synthesis.
• Host-rate spectral processing under rack oversampling, with FIR filtering before decimation and after interpolation.
• Formant-envelope work is skipped when FORMANT is zero. Processing storage is prepared outside the audio callback.
• Maintained alignment across effect dry/wet, POWER OFF, serial instances, parallel racks, master dry and separate band outputs. Extended the reserved delay-compensation storage.
• Existing GUITAR instances receive the corrected v1.4.2 DSP with their saved settings. The faulty v1.4.1 sound is intentionally not preserved.

LATENCY OF ONE PITCH INSTANCE
Sample rate 1x OS 2x / 4x / 8x OS
44.1 kHz 29.025 ms 29.751 ms
48 kHz 26.667 ms 27.333 ms
96 kHz 26.667 ms 27.000 ms

These are module delays, not complete monitoring round-trip figures. Crossovers, master stages, the host and interface add further delay. Both engines are aligned to the same instance delay; LEGACY therefore has more monitoring latency than in v1.4.0. The earlier 12/13.06 ms figures do not describe v1.4.2. No zero-latency or sub-15 ms claim is made.

PRESETS AND AUTOMATION

• Appended nine host parameters in v1.4.1, increasing the total from 1007 to 1016. V1.4.2 adds no further parameters.
• Preserved all pre-existing parameter IDs, indices, types and ranges, including historical Pitch and Snap. New controls use separate parameters.
• Retained per-instance state, schema-v4 support, the product/manufacturer names and VST3 class IDs.
• First-instance controls notify the host; duplicate FX retain independent saved values. No manual conversion of existing presets is required. Older plugin versions cannot reproduce features they do not contain.
• Pitch FX RANDOM selects GUITAR with whole-semitone Pitch and neutral Cents/Formant; Input, Output and Power remain unchanged.

VALIDATION AND USER ACCEPTANCE
Release x64 VST3 built successfully. Native checks passed for transposition, harmonic multi-note input, variable blocks from 1 to 2048 samples, saved state, parameter indices, wet/dry and power behaviour, measured delay, serial/parallel alignment, filtered sample-rate conversion and ROUTING.

The full isolated-MID test used LOW/HIGH muted, crossovers at the extremes, -2 semitones, FX MIX 100% and MASTER MIX 100%. It produced 220 -> 195.998 Hz and the expected shifted components of a three-note harmonic input. The owner subsequently confirmed the v1.4.2 fix after listening to the guitar-DI setup.

V1.4.1 was an intermediate implementation: it introduced the new controls and first GUITAR engine, but the guitar-DI result was rejected. V1.4.2 contains the corrected implementation described here; these local builds are not presented as separate previously published releases.

PRACTICAL LIMITS
Processing can change individual-note levels. At 96 kHz and 32-sample host buffers, measured callback peaks can still exceed the available budget. Acceptance in the tested setup is not a guarantee of transparent processing or safe real-time operation for every signal, chain length or buffer setting.

Pitch instances still process their own rack bands. Other bands and MASTER MIX can retain an unshifted component. Extreme crossover positions do not bypass the finite FIR filters; their transition regions can affect the low end even with LOW/HIGH muted. This update does not change crossover routing or add a full-band pre-crossover insert.

All other product functions remain part of the v1.4.0 baseline. The full v1.4.0 notes are preserved in GITHUB_REALESE_V1.4.0.txt. Windows x64 VST3; freeware binaries, private development sources.