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Overview

Apollo Monitor is a lightweight menu bar utility that gives you instant access to your Universal Audio Apollo Solo's monitor controls without needing to open the full UA Console application.

Perfect for producers, engineers, and musicians who want quick access to essential monitoring functions while working in their DAW.

Features

Feature	Description
Volume Control	Precise dB control with visual slider (-∞ to 0 dB)
Mute	One-click mute toggle with visual feedback
Dim	-17dB dim function for quick level reduction
Mono	Mono summing for checking mix translation
Real-time Sync	Bi-directional sync with UA Console app
Native UI	Built with SwiftUI, follows Apple Human Interface Guidelines
Lightweight	Runs silently in menu bar, minimal resource usage

Requirements

• macOS 14.0 (Sonoma) or later
• Universal Audio Apollo Solo (Thunderbolt)
• UA Console app must be running

Installation

Option 1: Download Release

1. Download the latest .dmg from Releases
2. Open the DMG and drag ApolloMonitor.app to your Applications folder
3. First launch only: Right-click the app → Open → Open (see note below)
4. The app will appear in your menu bar with a dial icon

⚠️ Security Note: This app is not notarized with Apple (requires $99/year developer account). macOS will block it on first launch. To open:

• Right-click (or Control-click) on ApolloMonitor.app
• Select Open from the menu
• Click Open in the dialog

You only need to do this once. After that, the app will open normally.

Option 2: Build from Source

# Clone the repository
git clone https://github.com/noiseheroes/ApolloMonitor.git
cd ApolloMonitor

# Open in Xcode
open ApolloMonitor.xcodeproj

Then in Xcode:

1. Select your Development Team in Signing & Capabilities
2. Build and Run (⌘R)

Usage

1. Click the dial icon in your menu bar to open the control panel
2. Drag the slider to adjust monitor volume (-∞ to 0 dB)
3. Click the buttons to toggle Mute, Dim, or Mono
4. The panel automatically closes when you click outside

Controls

Control	Function	Visual Indicator
Volume Slider	Adjusts monitor output level	Blue slider + dB display
Mute	Silences monitor output	Red highlight when active
Dim	Reduces level by 17dB	Orange highlight when active
Mono	Sums stereo to mono	Purple highlight when active

How It Works

Apollo Monitor communicates with the UA Console application via a local TCP socket on port 4710. This is the same internal protocol used by Universal Audio's own software.

Technical Details

Protocol: TCP/IP
Port: 4710
Host: 127.0.0.1 (localhost)
Format: JSON over null-terminated strings

Supported Commands

Parameter	Path	Type
Monitor Level	/devices/0/outputs/4/CRMonitorLevel	Float (dB)
Mute	/devices/0/outputs/4/Mute	Boolean
Dim	/devices/0/outputs/4/DimOn	Boolean
Mono	/devices/0/outputs/4/MixToMono	Boolean

Project Structure

ApolloMonitor/
├── ApolloMonitor/              # Main menu bar app
│   ├── ApolloMonitorApp.swift  # App entry point
│   ├── AppDelegate.swift       # Menu bar setup & lifecycle
│   ├── MonitorView.swift       # SwiftUI interface
│   └── Info.plist              # App configuration
│
├── ApolloMonitorWidget/        # macOS Widget (WidgetKit)
│   └── ApolloMonitorWidget.swift
│
├── Shared/                     # Shared code between targets
│   ├── ApolloController.swift  # State management (ObservableObject)
│   └── ApolloTCP.swift         # TCP client for UA Console
│
├── Assets.xcassets/            # App icon and assets
├── project.yml                 # XcodeGen configuration
└── README.md

Troubleshooting

App shows "Connecting..." but never connects

• Make sure UA Console is running
• Check that your Apollo Solo is connected and powered on
• Try clicking the refresh button in the app footer

Volume changes don't sync with UA Console

• Ensure you're controlling the correct output (Monitor output 4)
• Restart both Apollo Monitor and UA Console

App doesn't appear in menu bar

• Check System Settings → Control Center → Menu Bar Only
• Try quitting and relaunching the app

Credits

Protocol Discovery

The TCP protocol for communicating with Universal Audio devices was discovered and documented by the cuefinger project by @tschiemer.

This project would not be possible without their excellent reverse engineering work on the UA Console protocol.

Development

• Created by Noise Heroes
• Built with assistance from Claude by Anthropic

License

This project is licensed under the MIT License — see the LICENSE file for details.

Disclaimer

This is an unofficial third-party application.

Universal Audio, Apollo, Apollo Solo, and UA Console are trademarks of Universal Audio, Inc. This project is not affiliated with, endorsed by, or sponsored by Universal Audio.

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Made with ♥ for the audio community