mlx-community/ACE-Step-1.5-turbo-bf16

ACE-Step 1.5 turbo (DiT + condition encoder + FSQ tokenizer / detokenizer) — MLX, bf16. Converted from ACE-Step/Ace-Step1.5 @ 19671f4 by the converter of xocialize/mlx-ace-step-swift (Tools/convert/convert.py, mlx 0.32.4), a full port of ace-step/ACE-Step-1.5 @ ca1e85f to Swift-MLX.

What is in the bundle

acestep-v15-turbo of ACE-Step 1.5 in MLX layout, bf16: the 2 B flow-matching DiT (24 layers, alternating sliding-128 / full attention, adaLN, cross-attention), the condition encoder (lyric encoder 8 layers, timbre encoder 4 layers, text projector), the FSQ audio tokenizer (attention pooler + ResidualFSQ, levels [8, 8, 8, 5, 5, 5]) and the 2-layer detokenizer — 677 tensors, keys as in the checkpoint except decoder.proj_in.1 / decoder.proj_out.1 → decoder.proj_in / decoder.proj_out with the convolutions in MLX's [out, k, in] layout; plus silence_latent.safetensors ([15000, 64] fp32, the silence latent the pipeline pads and references with). config.json is the checkpoint's with an mlx_ace_step provenance block.

Licence

MIT. The Hugging Face repository ACE-Step/Ace-Step1.5 ships no LICENSE file; its model-card tag and README state MIT and the GitHub LICENSE (Copyright (c) 2026 ACEStep) is the controlling text.

The full notice travels with the bundle as NOTICE; LICENSE is the MIT text. Nothing in the weights is modified beyond the layout conversion (key prefix / conv layout / weight-norm folding) — the converter Tools/convert/convert.py in xocialize/mlx-ace-step-swift is gated bit-equal against upstream's own dit_convert.py / vae_convert.py (its MEASUREMENTS.md §V1).

Use

Every tier of the Swift package loads four bundles — the turbo DiT, one planner, the text encoder and the VAE — and this bundle is one of them. The planner choices: ACE-Step-1.5-planner-1.7B-8bit for .int8 (the default), -4bit for .int4, -bf16 for .bf16 / .fp32, and ACE-Step-1.5-planner-0.6B-bf16 for the lite planner on any tier. The package, xocialize/mlx-ace-step-swift, runs ACE-Step 1.5 on Apple Silicon through MLX Swift and plugs into MLXEngine on the music capability (caption + lyrics → a 48 kHz stereo song; reference-audio timbre; cover / repaint / extend of a source clip; LRC timestamps). The package's ACEStepConfiguration names these repos and the engine materialises them; the parity gates against the upstream oracle (fp32, TF32 off) are recorded in the package's MEASUREMENTS.md.

let engine = MLXServeEngine()
let id = try await engine.register(ACEStepPackage.registration, configuration: ACEStepConfiguration())   // the .int8 default
try await engine.prepare(.music, package: id)
let song = try await engine.run(MusicRequest(caption: "…", lyrics: "[Verse]\n…", durationSeconds: 120, seed: 7), package: id)

Upstream: ACE-Step/Ace-Step1.5 @ 19671f4 (weights), ace-step/ACE-Step-1.5 @ ca1e85f (code) — ACE Studio + StepFun, tech report.