---
title: Diamond — Speech Restoration
emoji: 💎
colorFrom: blue
colorTo: indigo
sdk: gradio
sdk_version: 6.20.0
app_file: app.py
pinned: false
license: apache-2.0
short_description: Restore degraded speech to studio 44.1 kHz
models:
- nineninesix/diamond-1.0
---

# 💎 Diamond — Speech Restoration

Turn degraded speech (podcast, phone, streamed, over-compressed) into
near-studio **44.1 kHz** audio.

Diamond is an **RQ-Transformer**: degraded speech → log-mel → Transformer
encoder → time-transformer (causal self- and cross-attention) → depth-transformer
(a small local autoregression over the 9 DAC RVQ codebooks per frame) → frozen
DAC decoder → restored 44.1 kHz waveform. Decoding is chunked greedy with a
repetition penalty to suppress autoregressive looping.

Runs on **ZeroGPU** — the model lives on CPU between requests and is moved to the
GPU only for the duration of a restoration call.

- **Model:** [`nineninesix/diamond-1.0`](https://huggingface.co/nineninesix/diamond-1.0)
- **Training code:** [`diamond-train`](https://github.com/nineninesix-ai/diamond-train.git)
- **Inference code:** [`diamond-inference`](https://github.com/nineninesix-ai/diamond-inference.git)
- **License:** Apache-2.0