Fosi Audio PH05
Fosi Audio PH05 5-Channel Headphone Splitter Amplifier User Manual
Model: PH05 | Brand: Fosi Audio
1. Introduction
The Fosi Audio PH05 is a versatile one-in-five-out stereo headphone splitter/amplifier designed for professional audio monitoring and distribution systems. It allows you to connect up to five sets of headphones simultaneously, adapting to various audio-sharing and distribution scenarios. This manual provides detailed instructions for setting up, operating, and maintaining your PH05 amplifier.

Figure 1: Fosi Audio PH05 5-Channel Headphone Splitter Amplifier.
2. What's in the Box?
- PH05 Headphone Splitter/Amplifier
- Power Adapter (DC 12V)
- 3.5mm AUX Cable
- User Manual (this document)

Figure 2: PH05 Headphone Splitter/Amplifier.

Figure 3: Included Power Adapter.

Figure 4: Included 3.5mm AUX Cable.
3. Product Overview
The Fosi Audio PH05 features a user-friendly design with intuitive controls and clear labeling for easy operation.
Front Panel Controls and Indicators:
- CH1-CH5 Volume Knobs: Independent level control for each of the five headphone output channels.
- Master Volume Knob (VOL): Controls the overall output volume for all channels.
- Power/Mute Button: Press to mute/unmute audio. Long press to power on/off the device.
- Power/Mute Indicator Light: Indicates power status and mute status.
Rear Panel Connections:
- INPUT (3.5mm AUX): Audio input jack for connecting your source device.
- Ω1-Ω5 (3.5mm Headphone Outputs): Five independent 3.5mm headphone output jacks.
- DC-12V: Power input jack for the included 12V power adapter.

Figure 5: Detailed view of PH05 controls and ports.
4. Setup
- Connect Audio Source: Use the included 3.5mm AUX cable to connect your audio source (e.g., smartphone, tablet, computer, mixer) to the INPUT jack on the rear panel of the PH05.
- Connect Headphones: Plug your headphones or IEMs into any of the five Ω1-Ω5 output jacks on the rear panel. You can connect up to five pairs simultaneously.
- Connect Power: Insert the DC 12V power adapter into the DC-12V power input jack on the rear panel, then plug the adapter into a standard wall outlet.
- Power On: Long press the Power/Mute button on the front panel to power on the device. The indicator light will illuminate.

Figure 6: Example setup with multiple headphones connected.
5. Operating Instructions
- Adjust Master Volume: Rotate the large Master Volume Knob (VOL) to set the overall listening level for all connected headphones. Start with a low volume and gradually increase it to a comfortable level.
- Adjust Individual Channel Volume: Use the individual CH1-CH5 Volume Knobs to fine-tune the volume for each connected headphone. This allows for personalized listening levels for each user.
- Mute/Unmute: Short press the Power/Mute button to instantly mute or unmute all audio output. The indicator light will change to reflect the mute status.
- Power Off: Long press the Power/Mute button to power off the device when not in use.

Figure 7: User-friendly control design with individual and master volume knobs.
Usage Scenarios:
The PH05 is ideal for various applications:
- Music Studio Production: Monitor audio with multiple headphones during recording or mixing sessions.
- Podcasting: Allow multiple participants to monitor audio during live recordings.
- Classroom Teaching: Provide individual audio feeds for students in a learning environment.
- Audio Sharing: Share audio from a single source with friends or family, such as watching TV or listening to music.

Figure 8: PH05 adapting to various listening scenarios.
Official Product Video:
Video 1: Overview of the Fosi Audio PH05 5-Channel Headphone Splitter Amplifier, demonstrating its features and applications.
6. Maintenance
- Cleaning: Use a soft, dry cloth to clean the exterior of the device. Avoid using harsh chemicals or abrasive cleaners.
- Storage: When not in use for extended periods, store the PH05 in a cool, dry place away from direct sunlight and extreme temperatures.
- Handling: Handle the device with care. Avoid dropping it or subjecting it to strong impacts.
7. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No sound output |
|
|
| Distorted sound |
|
|
| Humming or buzzing noise |
|
|
8. Specifications
| Feature | Detail |
|---|---|
| Product Dimensions | 4.61 x 3.11 x 1.96 inches (117 x 79 x 50 mm) |
| Item Weight | 1.1 pounds (340g) |
| Output Power | Up to 310mW @ 32Ω per channel (x5) |
| Compatible Headphone Impedance | 16-300 Ohm |
| Signal-to-Noise Ratio (SNR) | 105dB |
| Total Harmonic Distortion (THD) | 0.001% |
| Noise Floor | 25µV |
| Power Input | DC 12V |
| Manufacturer | Fosi Audio |

Figure 9: PH05 demonstrating superior sound performance with low noise and distortion.
9. Warranty & Support
Fosi Audio products come with a standard manufacturer's warranty. For detailed warranty information, technical support, or service inquiries, please visit the official Fosi Audio website or contact their customer service directly.
Official Website: www.fosiaudio.com
You may also find additional support and FAQs on the product page where you purchased the item.
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