Zonos v0.1 is a ~500M-parameter text-to-speech model trained on 200k+ hours of multilingual speech. It delivers expressive, high-quality synthesis with fine-grained control over:

Speaker cloning from a few seconds of reference audio
Emotion control (happiness, sadness, disgust, fear, surprise, anger, neutral)
Speaking rate (phonemes/second)
Pitch variation (pitch standard deviation)
Audio quality (fmax parameter)

Output is native 44.1 kHz mono PCM via a 9-codebook DAC decoder.

Architecture

Text input → eSpeak phonemization → phoneme embeddings
Prefix conditioner: concatenates conditioning embeddings (phonemes, speaker, emotion, fmax, pitch_std, rate, language) through projection + LayerNorm
AR backbone: 26-layer GPT-style transformer (d=2048, GQA 16q/4kv, SwiGLU, LayerNorm with bias, RoPE) generates 9 interleaved DAC codebook streams with delay pattern
Classifier-free guidance (CFG): both conditioned and unconditioned prefixes are decoded; logits are interpolated with configurable scale (default 2.0)
DAC decoder: separate GGUF converts 9-codebook RVQ codes → 44.1 kHz PCM

Files

File	Size	Description
`zonos-v0.1-transformer-f16.gguf`	3.1 GB	Full-precision (F16) — reference quality
`zonos-v0.1-transformer-q4_k.gguf`	872 MB	Q4_K quantised — ~3.5x smaller, good quality

Required companion

Zonos needs the DAC 44.1 kHz decoder GGUF for audio output. Use dac-44khz.gguf from cstr/dia-1.6b-GGUF (same codec, shared between Zonos and Dia backends).

Usage

CrispASR CLI

bash

# Download
crispasr -m auto --backend zonos

# Synthesize
crispasr --backend zonos \
  -m zonos-v0.1-transformer-q4_k.gguf \
  --tts-codec dac-44khz.gguf \
  --tts "Hello, this is a test of the Zonos text to speech system." \
  -o output.wav

# With emotion control
crispasr --backend zonos \
  -m zonos-v0.1-transformer-q4_k.gguf \
  --tts-codec dac-44khz.gguf \
  --tts "I'm so happy to see you!" \
  --emotion "0.8,0,0,0,0,0,0,0.2" \
  -o happy.wav

# With voice cloning
crispasr --backend zonos \
  -m zonos-v0.1-transformer-f16.gguf \
  --tts-codec dac-44khz.gguf \
  --voice reference.wav \
  --tts "Cloned voice output." \
  -o cloned.wav

CrisperWeaver (Flutter GUI)

Download from Model Management, select on the Synthesize screen, and set dac-44khz.gguf as the codec companion.

C API

#include "crispasr.h"

// Open session
crispasr_session* s = crispasr_session_open("zonos-v0.1-transformer-q4_k.gguf", "zonos");
crispasr_session_set_codec_path(s, "dac-44khz.gguf");

// Configure (optional)
crispasr_session_set_temperature(s, 0.7);

// Synthesize
int n_samples;
float* pcm = crispasr_session_synthesize(s, "Hello world", &n_samples);
// ... write pcm to WAV ...
free(pcm);
crispasr_session_free(s);

Conditioning Parameters

Parameter	Range	Default	Description
`pitch_std`	0-400	45	Pitch variation. 20-45 = normal, 60-150 = expressive
`speaking_rate`	0-40	15	Phonemes per second. 10 = slow, 15 = normal, 30 = fast
`fmax`	0-24000	24000	Maximum frequency. 22050 for voice cloning
`cfg_scale`	0-10	2.0	Classifier-free guidance scale
`emotion`	8 floats	neutral	[happiness, sadness, disgust, fear, surprise, anger, other, neutral]
`temperature`	0-2	0.0	Sampling temperature (0 = greedy)

Conversion

Converted from the upstream PyTorch checkpoint using:

bash

python models/convert-zonos-to-gguf.py \
  --input Zyphra/Zonos-v0.1-transformer \
  --output zonos-v0.1-transformer-f16.gguf

Quantised with:

crispasr-quantize zonos-v0.1-transformer-f16.gguf zonos-v0.1-transformer-q4_k.gguf q4_k

License

Apache 2.0 (same as Zyphra/Zonos-v0.1-transformer).

cstr/zonos-v0.1-transformer-GGUF

Zonos v0.1 Transformer — GGUF

Model