Marvis is a cutting-edge conversational speech model designed to enable real-time streaming text-to-speech synthesis. Built with efficiency and accessibility in mind, Marvis addresses the growing need for high-quality, real-time voice synthesis that can run on consumer devices such as Apple Silicon, iPhones, iPads, Macs and others.

Key Features

Real-time Streaming: Stream audio chunks as text is processed, enabling natural conversational flow
Compact Size: Only 500MB when quantized, enabling on-device inference
Edge deployment: Optimized for real-time Speech-to-Speech (STS) on mobile devices (i.e., iPad, iPhone and etc)
Natural Audio Flow: Process entire text context for coherent speech synthesis without chunking artifacts
Multimodal Architecture: Seamlessly handles interleaved text and audio tokens

Supported Languages

Currently optimized for English with support for expressive speech synthesis with additional languages such as German, Portuguese, French and Mandarin coming soon.

Quick Start

Using MLX

bash

pip install -U mlx-audio
python -m mlx_audio.tts.generate --model Marvis-AI/marvis-tts-250m-v0.1  --stream \
 --text "Marvis TTS is a new text-to-speech model that provides fast streaming on edge devices."

Using transformers

Without Voice Cloning(Colab Notebook)

python

import torch
from transformers import AutoTokenizer, AutoProcessor, CsmForConditionalGeneration
from tokenizers.processors import TemplateProcessing
import soundfile as sf

model_id = "Marvis-AI/marvis-tts-0.25m-v0.1-transformers"
device = "cuda"if torch.cuda.is_available() else "cpu"

# load the model and the processor
processor = AutoProcessor.from_pretrained(model_id)
model = CsmForConditionalGeneration.from_pretrained(model_id).to(device)

# prepare the inputs
text = "[0]Marvis TTS is a new text-to-speech model that provides fast streaming on edge devices." # `[0]` for speaker id 0
inputs = processor(text, add_special_tokens=True, return_tensors="pt").to(device)
# infer the model
audio = model.generate(input_ids=inputs['input_ids'], output_audio=True)
sf.write("example_without_context.wav", audio[0].cpu(), samplerate=24_000, subtype="PCM_16")

Output:

Model Description

Marvis is built on the Sesame CSM-1B (Conversational Speech Model) architecture, a multimodal transformer that operates directly on Residual Vector Quantization (RVQ) tokens and uses Kyutai's mimi codec. The architecture enables end-to-end training while maintaining low-latency generation and employs a dual-transformer approach:

Multimodal Backbone (250M parameters): Processes interleaved text and audio sequences to model the zeroth codebook level, providing semantic understanding and context.
Audio Decoder (60M parameters): A smaller, specialized transformer that models the remaining 31 codebook levels to reconstruct high-quality speech from the backbone's representations.

Unlike models that require text chunking based on regex patterns, Marvis processes entire text sequences contextually, resulting in more natural speech flow and intonation.

Training Details

Pretraining:

Dataset: Emilia-YODAS
Training Steps: 2M steps
Hardware: 1x NVIDIA GH200 96GB
Precision: bfloat16
Learning Rate: 3e-4
Batch Size: 64

Post-training:

Dataset: Expressive Speech
Training Steps: 200K steps
Expressiveness Setting: 0.5
Hardware: 1x NVIDIA GH200 96GB
Precision: bfloat16
Learning Rate: 1e-4
Batch Size: 64

Total Training Cost: ~$2,000

Pretraining and fine-tuning: $246.69 (1x GH200)
Post-training data generation: $167.94 (RTX6000 Ada)
Additional experimentation: ~$1,500 across various GPU configurations
Platforms: Prime-Intellect and Jarvis-Labs

Use Cases

Real-time Voice Assistants: Deploy natural-sounding voice interfaces with custom voices
Content Creation: Generate voiceovers and narration with personalized voices
Accessibility Tools: Create personalized speech synthesis for communication aids
Interactive Applications: Build conversational AI with consistent voice identity
Podcast & Media: Generate natural-sounding speech for automated content

Local & Cloud Deployment

Local Deployment:

Minimum Requirements: 1GB RAM, GPU recommended for real-time inference
Quantized Model: 500MB download
Platforms: iOS, Android, Windows, macOS, Linux

Cloud Deployment:

API-ready architecture
Scalable inference pipeline
Low-latency streaming support

Technical Limitations

Language Support: Currently optimized primarily for English. Performance on other languages may be suboptimal
Audio Quality Dependency: Voice cloning quality is dependent on the clarity and quality of the 10-second reference audio
Background Noise: Performance degrades with noisy reference audio or inference environments
Hallucinations: The model might hallucinate words specially for new words or short sentences.

Legal and Ethical Considerations:

Users are responsible for complying with local laws regarding voice synthesis and impersonation
Consider intellectual property rights when cloning voices of public figures
Respect privacy laws and regulations in your jurisdiction
Obtain appropriate consent and permissions before deployment

License & Agreement

Apache 2.0

Citation

If you use Marvis in your research or applications, please cite:

bibtex

@misc{marvis-tts-2025,
  title={Marvis-TTS: Efficient Real-time Voice Cloning with Streaming Speech Synthesis},
  author={Prince Canuma and Lucas Newman},
  year={2025}
}

Acknowledgments

Special thanks to Sesame and Kyutai for their groundbreaking open-source contributions that inspired our work, and to the broader open-source community for their unwavering support and collaboration.

Version: 0.1

Release Date: 26/08/2025

Creators: Prince Canuma & Lucas Newman

Marvis-AI/marvis-tts-250m-v0.1-transformers

Introduction