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.
3.0 KiB
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.