Stable Audio 3 — MLX weights v2 (aligned for mapping)

Stable Audio 3 (Small-Music and Medium) — MLX weights for WhisperKit, v2

These files are format conversions of weights published by Stability AI at
https://huggingface.co/stabilityai/stable-audio-3-optimized. Nothing was
retrained or altered: the MLX .npz archives were rewritten as safetensors,
which is the only container MLX Swift can read, and the tokenizer and three
conditioner tensors were extracted from those same archives.

v2 contains the same tensors as sa3-small-weights-v1, rewritten so every
tensor starts on a 64-byte boundary (ports/stable-audio-3/align_weights.py).
The app maps these files instead of reading them into memory, which takes
Medium from 3.5 GB to about 0.6 GB while generating.

File	Contents
t5gemma_f16.safetensors	T5Gemma text encoder
dit_sm-music_f16.safetensors	Diffusion transformer, small-music
dit_medium_f16.part1/2.safetensors	Diffusion transformer, medium (sharded: 2.9 GB exceeds the 2 GB asset cap)
same_s_decoder_f32.safetensors	SAME-S audio decoder
sa3_conditioner_*.safetensors	Conditioner tensors from each DiT archive
t5gemma_tokenizer.model	SentencePiece tokenizer from the T5Gemma archive

Licensing

• Stable Audio 3 weights: Stability AI Community License (STABILITY_LICENSE.md).
• T5Gemma: Gemma Terms of Use — https://ai.google.dev/gemma/terms.

Both apply unchanged to these conversions. The Swift pipeline that loads them is
adapted from https://github.com/kellyvv/StableAudio3-IOS (MIT).