ACE-Step 1.5
AutorunX's owned, self-hosted open-source music engine — Apache 2.0 licensed and the cheapest song-generation option available.

Picking ACE-Step as the model for a generation.
What ACE-Step does
ACE-Step produces a full song — composition, vocals, instrumentation, and mix — from a text prompt or lyric sheet, the same kind of input as AutorunX's other song engines.
The difference is where it runs: instead of calling a paid third-party cloud API, it executes on AutorunX's own GPU pod, which is what keeps its per-song cost the lowest on the platform.
Key features
Fast owned-infra generation
The diffusion + DCAE + lightweight-transformer architecture is built for speed, producing coherent songs quickly even on modest GPU hardware.
Apache 2.0, open weights
Fully open source, with published weights and code, which is what lets AutorunX self-host it without per-call licensing costs.
Lowest cost per song on AutorunX
At 25 credits per song, it's roughly 2-3x cheaper than AutorunX's cloud song-generation alternatives.
Optional RVC voice conversion pairing
Swap the rendered vocal's timbre to a different singer in a follow-up RVC pass after the song is generated.
Vast + RunPod GPU lane
Runs on AutorunX's own Vast pod, with automatic fallback to RunPod if the primary pod is unavailable.
How ACE-Step works
ACE-Step combines diffusion-based audio generation with a deep-compression autoencoder (derived from Sana's DCAE) and a lightweight linear transformer, letting it synthesize several minutes of coherent music far faster than LLM-token-based music models — publicly benchmarked at roughly 15x faster generation than autoregressive baselines on comparable hardware.
Because it's fully open source under Apache 2.0, with published weights and code, AutorunX runs it directly on its own GPU infrastructure — a Vast pod as the primary lane, RunPod as fallback — rather than calling a third-party API. That's what makes it the lowest-cost song-generation path on the platform: no per-call provider markup, just AutorunX's own compute.
On AutorunX, ACE-Step can optionally be paired with RVC (Retrieval-based Voice Conversion) for singer/voice conversion, letting a generated vocal take on a different singer's timbre after the song itself has been composed and rendered.
What people use ACE-Step for
High-volume iteration
Generate many drafts or variations of a song idea cheaply before spending more credits on a premium engine for the final take.
Budget-conscious background music
Produce batch background tracks or jingles where per-generation cost adds up quickly across many pieces.
Fully open-source generation chain
Use it where licensing clarity from an Apache 2.0 model matters as part of a project's requirements.
Songs with a planned re-voice
Generate the song first with ACE-Step, then chain an RVC voice conversion pass to apply a specific singer's timbre.
Who built ACE-Step
ACE Studio & StepFun
github.comACE-Step is an open-source music generation foundation model jointly developed by ACE Studio and StepFun, released under the Apache 2.0 license. It combines diffusion-based generation with a compressed audio autoencoder and a lightweight transformer, built to produce full songs far faster than comparable LLM-based music models while remaining free to self-host and fine-tune.
How to use ACE-Step on AutorunX
ACE-Step is available in Song Builder in Music Lab.
Open the service
Go to Music Lab and open the Song Builder editor.
Set up your input
Enter a style prompt or paste a full lyric sheet for the song you want.
Pick ACE-Step
Open the engine picker and select ACE-Step — the owned, cost-efficient option, not the default.
Generate
Run the job, review the track, and optionally chain an RVC voice conversion pass.

An example generation rendered with ACE-Step.
Credit usage
Billed per completed song, from your shared AutorunX credit wallet.
Tips for better results with ACE-Step
Use it as your default first pass
As the cheapest option, it's a good engine to iterate with before spending more credits on a premium alternative for the final version.
Pair with RVC for a specific voice
If you want a particular singer's timbre rather than the generated default, chain an RVC voice conversion pass after generation.
Spot-check against premium engines
Occasionally compare a favorite prompt against Suno v5 or Lyria 3 to judge the quality-versus-cost tradeoff for your use case.
Prompt with the same care as any engine
Clear genre, mood, and structure cues in your prompt or lyric sheet still drive the quality of ACE-Step's output.
ACE-Step — frequently asked questions
Related models
Suno v5
Suno's song-generation model — full arranged tracks with vocals from a prompt.
Music GenerationMusicful
A cloud prompt-to-song API that turns text prompts or lyrics into fully produced tracks, selectable in Song Builder.
Music GenerationLyria 3
Google DeepMind's latent-diffusion music model, reached via OpenRouter, as a selectable song-generation engine in AutorunX.
Ready to create with ACE-Step?
Sign up for AutorunX to get 200 free credits across every lab, including Song Builder.