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esh-pfi-infrastructure/stacks/voxtral/README.md
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vh 16d018ff96 stacks/{fish-s2,voxtral,kyutai-tts}: three new TTS deploys for irv-ml1 quality A/B
Adds the three premier 2026 TTS releases we missed during the original
fleet build-out (early April), all licensed for self-host:

* Fish Audio S2-Pro (port 8195, GPU 1 / A6000) — released 2026-03-09.
  4B dual-AR (Slow + Fast) trained on 10M+ hours / 80+ languages.
  Headline: 15,000+ paralinguistic / emotion tags via natural language
  ([laugh] [whispers] [super happy] etc.) — a step-function over
  Chatterbox Turbo's 9 fixed tags. 91.61% paralinguistic win rate on
  EmergentTTS-Eval. ~150 ms streaming TTFB, voice cloning, MIT-style
  open. ~17 GB VRAM.

* Voxtral TTS (port 8197, GPU 1 / A6000) — Mistral, released 2026-03-28.
  4B open-weight, 70 ms model latency, 9.7× realtime. 68.4% blind A/B
  win rate vs ElevenLabs Flash v2.5 in cloning. 8 languages
  (EN/FR/DE/ES/IT/PT/NL/HI). Served via vLLM-Omni (Mistral's partner
  serving stack) — published Docker image, no local build. ~16 GB VRAM.
  CC BY-NC license — personal/research use only; flagged in README.

* Kyutai TTS (port 8198, GPU 0 / 3090) — kyutai/tts-1.6b-en_fr.
  Trained on 2.5M hours from the Moshi/Mimi team. Claimed 220 ms in
  solo setup, 32 simultaneous streams under 350 ms on L40. Kyutai's
  official deploy is Rust + websockets only; using NillPointer's
  community OpenAI-compat wrapper to bridge to /v1/audio/speech so
  it slots into the same bench harness. ~4-6 GB VRAM.

Each stack: compose.yaml (build context, env, volumes, healthcheck,
homepage label), .env.example (all tunables documented), README.md
(why it exists, headline numbers, API, deploy + hardware notes).
Playbooks at playbooks/deploy-{fish-s2,voxtral,kyutai-tts}.yaml are
idempotent in the same shape as the existing deploy-vibevoice /
deploy-chatterbox playbooks.

Port allocations on irv-ml1 after this lands: 8188 ComfyUI, 8190
CosyVoice, 8191 Qwen3-TTS, 8192 IndexTTS-2, 8193 Kokoro, 8194
VibeVoice, 8195 Fish, 8196 Chatterbox, 8197 Voxtral, 8198 Kyutai,
8765 Parakeet ASR.
2026-04-27 22:40:10 -07:00

3.0 KiB
Raw Blame History

Voxtral TTS

mistralai/Voxtral-4B-TTS-2603 — Mistral AI's 4B open-weight streaming TTS, served via the vLLM-Omni production serving stack (Mistral co-developed). Released March 28, 2026.

⚠️ License

CC BY-NC. Personal use, research, and internal tooling are fine. Don't ship Voxtral output in any commercial product without re-licensing from Mistral. The other TTS in this fleet (Kokoro, Chatterbox, Fish S2-Pro, IndexTTS-2, Qwen3-TTS, CosyVoice) are all open-licensed and clean for commercial work.

Why this stack exists

Multilingual streaming with serious speed:

use case
Voxtral multilingual EN/FR/DE/ES/IT/PT/NL/HI streaming, 70 ms model latency
Kokoro low-latency English, fixed voice library
Chatterbox Turbo low-latency English w/ cloning + 9 paralinguistic tags
Fish Audio S2-Pro richest paralinguistic English (15k+ tags)
IndexTTS-2 English voice cloning + emotion vector / text control
Qwen3-TTS-1.7B English voice cloning (slow on official backend)
CosyVoice 3 multilingual (Chinese-leaning)
VibeVoice 1.5B long-form / multi-speaker dialogue

Voxtral fills the multilingual + low-latency + cloning slot that's been weak in the fleet (CosyVoice is multilingual but slow on English; nothing else is multilingual at all).

Headline numbers

  • 70 ms model latency for a typical 10 s sample (500-char input)
  • 9.7× realtime factor
  • 68.4% blind A/B win rate vs ElevenLabs Flash v2.5 in voice cloning evaluations
  • 8 languages: EN, FR, DE, ES, IT, PT, NL, HI

API

vLLM-Omni serves an OpenAI-compatible API at http://10.100.79.3:8197/v1:

# Single-shot synthesis.
curl -fsS -X POST http://10.100.79.3:8197/v1/audio/speech \
  -H 'Content-Type: application/json' \
  -d '{"model":"mistralai/Voxtral-4B-TTS-2603","input":"Hello there.","voice":"alloy","response_format":"wav"}' \
  > out.wav

# Streaming.
curl -fsS -X POST http://10.100.79.3:8197/v1/audio/speech \
  -H 'Content-Type: application/json' \
  -d '{"model":"mistralai/Voxtral-4B-TTS-2603","input":"long passage…","voice":"alloy","stream":true}' \
  | mpv --no-cache -

# vLLM-Omni standard endpoints.
curl http://10.100.79.3:8197/v1/models    # confirms model loaded
curl http://10.100.79.3:8197/v1/audio/voices  # built-in + cloned voices

Deploy

scripts/elway irv-ml1 --playbook playbooks/deploy-voxtral.yaml

First boot pulls Voxtral-4B (~8 GB BF16) into the HF cache + warms vLLM. Both are cached afterwards.

Hardware footprint

  • VRAM: ~16 GB practical (8 GB weights + KV + activation). Pinned to GPU 1 (RTX A6000) by default — comfortable headroom. The 3090's 24 GB CAN fit but it's tight for long streaming sessions.
  • Disk: ~8 GB for the Voxtral checkpoint + HF cache.

Voice library

Drop reference WAV / FLAC into /worktank/voxtral/voices/ on the host. The wrapper scans on request — no restart needed.