ComfyUI-VoxCPMTTS

ComfyUI-VoxCPMTTS is a lightweight ComfyUI node for VoxCPM 1.5, featuring built-in automatic speech recognition for reference audio transcription.

Note

For LoRA training and dual-model support, see ComfyUI-VoxCPM.

Supported VoxCPM Versions

VoxCPM 1.0 (0.5B)

✅ Available in UI (16 kHz)

VoxCPM 1.5

✅ Default and recommended (44.1 kHz)

VoxCPM 2

❌ Not supported

This extension provides two node variants:

  • AILab_VoxCPMTTS — simplified node with hidden advanced parameters

  • AILab_VoxCPMTTS_Advanced — full control over all generation parameters

Features

  • TTS and voice cloning with VoxCPM 1.5 (44.1 kHz output); VoxCPM 0.5B also available in the UI

  • Auto-transcription of reference audio via faster-whisper (requires enabling auto_transcribe_reference)

  • Fade-in post-processing for smoother audio output (configurable fade_in_ms on Advanced node)

  • Simplified node uses fixed defaults (cfg_value=2.0, inference_steps=10); Advanced node exposes full manual control

  • REFERENCE_TEXT output port for inspecting ASR results

  • Configurable ASR model via environment variable VOXCPM_ASR_MODEL (tiny / small / medium / large)

  • Multi-device: auto (auto-detect), CUDA, MPS, CPU

Prerequisites

  • ComfyUI installed and running

  • PyTorch with appropriate backend

  • ~1.2 GB disk space for model downloads

Installation

  • Via ComfyUI Manager: search for VoxCPMTTS and install.

Manual installation:

cd ComfyUI/custom_nodes/
git clone https://github.com/1038lab/ComfyUI-VoxCPMTTS.git
pip install -r ComfyUI-VoxCPMTTS/requirements.txt
# Restart ComfyUI

Models are auto-downloaded on first use. Default path is ComfyUI/models/TTS/VoxCPM1.5/ for the 1.5 model, or ComfyUI/models/TTS/VoxCPM-0.5B/ if 0.5B is selected.

Basic usage

Text-to-Speech

  1. Add the VoxCPM TTS node (simplified) or VoxCPM TTS (Advanced) node

  2. Enter the text to synthesize

  3. The simplified node uses sensible defaults (cfg_value=2.0, inference_steps=10)

  4. The Advanced node lets you manually set cfg_value, inference_steps, and other parameters

Voice cloning

  1. Connect reference_audio with a reference audio clip

  2. For auto-transcription: enable auto_transcribe_reference on the node (required — leaving reference_text empty alone is not sufficient)

  3. Alternatively, provide the transcript manually in reference_text

  4. The REFERENCE_TEXT output shows the detected/provided transcript for verification

Advanced node parameters

Parameter

Description

cfg_value

Classifier-free guidance scale

inference_steps

LocDiT diffusion steps

max_length

Maximum generation token length

fade_in_ms

Fade-in duration for audio smoothing

retry_attempts

Maximum retries for bad outputs

retry_threshold

Threshold for bad-case detection

auto_transcribe_reference

Enable ASR for reference audio

normalize

Enable text normalization

unload_model

Unload model after inference to free VRAM

Troubleshooting

Out of Memory (OOM)

VoxCPM 1.5 requires significant VRAM. If you encounter OOM errors:

  • Enable unload_model to release GPU memory after each generation

  • Switch device to cpu (slower but uses system RAM)

  • Close other GPU-intensive applications

  • Try the Fast quality preset to reduce memory usage

Model download issues

If auto-download fails, manually download from Hugging Face and place files in ComfyUI/models/TTS/VoxCPM1.5/.

For debug logging, set COMFYUI_LOG_LEVEL=DEBUG.

Comparing with ComfyUI-VoxCPM

Feature

ComfyUI-VoxCPM

ComfyUI-VoxCPMTTS

Model support

VoxCPM 1.5 + 0.5B

VoxCPM 1.5 (recommended) + 0.5B

LoRA training

✅ Built-in

❌

Auto-transcription

❌ Manual only

✅ faster-whisper

Node variants

Single node

Simple + Advanced

Quality presets

Manual parameters

Fast / Balanced / HQ

Dependencies

Heavier (LoRA training)

Lighter