1. Introduction
The Fosi Audio K5 Pro is an upgraded headphone DAC amplifier combo designed for enhanced audio performance, particularly for gaming systems. It functions as an external sound card, compatible with various devices such as PS5, computers (PC/MAC), and active speakers. This device converts USB Type C, Optical, and Coaxial signals to 3.5MM AUX and RCA signals, offering low distortion and a wide dynamic range for richer audio details.
It incorporates the Texas Instruments NE5532 op-amp chip, optimized for a low-noise floor and clean sound, aiming to improve overall sound quality for an immersive audio experience.
Image 1: Front view of the Fosi Audio K5 Pro Gaming DAC Headphone Amplifier.
2. Package Contents
Please verify that all items listed below are included in your package:
- K5 Pro DAC amplifier x1
- 3.5MM headphone splitter x1
- 2-in-1 USB Type A/C to Type C cable x1
- User Manual x1
- Optical Cable x1
Image 2: All items included in the Fosi Audio K5 Pro retail package.
3. Product Overview and Controls
The Fosi Audio K5 Pro features intuitive controls and multiple input/output options for versatile connectivity.
Image 3: Detailed diagram showing the front and rear panels of the Fosi Audio K5 Pro, highlighting all ports and controls.
Front Panel Controls:
- Indicator Lights: USB, OPT (Optical), COA (Coaxial) to show active input.
- 3.5mm Headphone Output: For connecting headphones.
- 3.5mm Microphone Input: For connecting a microphone.
- Bass Control Knob: Adjusts the bass level.
- Treble Control Knob: Adjusts the treble level.
- Mode Select/Volume Control/Power Switch: Long press to power on/off, short press to select input mode, rotate to adjust volume.
Rear Panel Ports:
- USB-C / Power In: USB Type-C port for audio input and power.
- Optical Input: For connecting optical audio sources.
- Coaxial Input: For connecting coaxial audio sources.
- Right RCA Out (R): Right channel RCA audio output.
- Left RCA Out (L): Left channel RCA audio output.
4. Setup and Connections
The Fosi Audio K5 Pro offers multiple connection options for various devices. Ensure all connections are secure before powering on the unit.
General Connection Diagram:
Image 4: A comprehensive diagram illustrating how to connect different audio sources and output devices to the Fosi Audio K5 Pro.
Connecting to an iPhone:
- Use a USB-C to Lightning OTG Cable (not included).
- Plug the Lightning connector into your iPhone's Lightning port.
- Plug the Type-C side of the cable into the K5 Pro's USB-C port.
- Connect your speakers to the RCA outputs on the K5 Pro using RCA cables.
- Long press the Mode/Volume knob on the K5 Pro to power it on.
- Ensure the iPhone's audio output is directed to the K5 Pro.
Connecting to an Android Phone:
- Use the supplied 2-in-1 USB Type-C cable.
- Plug the Type-C side of the 2-in-1 connector into your phone's Type-C port.
- Plug the other side of the cable into the K5 Pro's USB-C port.
- Connect your speakers to the RCA outputs on the K5 Pro using RCA cables.
- Long press the Mode/Volume knob on the K5 Pro to power it on.
- Ensure the Android phone's audio output is directed to the K5 Pro.
Connecting to a Computer (PC/MAC):
- Use the supplied 2-in-1 USB Type-C cable.
- Plug the USB Type-A connector into a USB 2.0 or USB 3.0 port on your computer.
- Plug the Type-C side of the cable into the K5 Pro's USB-C port.
- Connect your headphones to the 3.5mm headphone output on the K5 Pro. If using a headset with a separate microphone jack, use the included Headset Microphone Two-in-one Adapter cable to connect both to the K5 Pro's headphone out and microphone port.
- Long press the Mode/Volume knob on the K5 Pro to power it on.
- On your computer, navigate to Sound settings (Windows: Control Panel > Sound; macOS: System Preferences > Sound) and select "Fosi Audio K5 Pro" as the output and input device.
Image 5: The Fosi Audio K5 Pro connected to a computer, illustrating its use in a gaming setup.
Image 6: The Fosi Audio K5 Pro connected to both headphones and active speakers, demonstrating its dual output capabilities.
Connecting to a PS5:
- Connect the supplied 2-in-1 USB Type-C cable to any USB port (Type-A or Type-C) on your PS5 console.
- Plug the Type-C side of the cable into the K5 Pro's USB-C port.
- Connect your headphones to the 3.5mm headphone output on the K5 Pro. If using a headset with a separate microphone jack, use the included Headset Microphone Two-in-one Adapter cable to connect both to the K5 Pro's headphone out and microphone port.
- Long press the Mode/Volume knob on the K5 Pro to power it on.
- On your PS5, go to Settings > Sound > Output Device and select "Fosi Audio K5 Pro".
Video Guide: How to Connect different Sources to K5 PRO via USB?
Video 1: A detailed video tutorial demonstrating how to connect the Fosi Audio K5 Pro to various devices including iPhone, Android phones, computers, and PS5 consoles using USB connections.
5. Operating Instructions
Power On/Off and Input Selection:
- To power on the K5 Pro, long press the Mode/Volume control knob. The indicator light for the currently selected input will illuminate.
- To power off the K5 Pro, long press the Mode/Volume control knob again.
- To select an input source (USB, Optical, Coaxial), short press the Mode/Volume control knob. The corresponding indicator light will change.
Volume Control:
- Rotate the Mode/Volume control knob clockwise to increase the volume.
- Rotate the Mode/Volume control knob counter-clockwise to decrease the volume.
Tone Controls (Bass and Treble):
The K5 Pro features dedicated knobs for adjusting bass and treble frequencies, allowing you to customize the sound to your preference.
- Rotate the Bass knob to increase or decrease the low-frequency response.
- Rotate the Treble knob to increase or decrease the high-frequency response.
Image 7: A hand adjusting the treble control knob on the Fosi Audio K5 Pro, demonstrating the accessible tone controls.
Image 8: The Fosi Audio K5 Pro connected to a pair of headphones, highlighting its capability to drive headsets with great sound quality.
6. Troubleshooting
If you encounter issues with your Fosi Audio K5 Pro, please refer to the following common problems and their solutions:
- No Sound Output:
- Ensure the K5 Pro is powered on (long press the Mode/Volume knob).
- Verify the correct input source is selected (short press the Mode/Volume knob). The corresponding indicator light should be on.
- Check all cable connections (USB, Optical, Coaxial, RCA, 3.5mm) are secure and correctly plugged in.
- Confirm the volume knob on the K5 Pro is turned up.
- If connected to a computer or PS5, ensure "Fosi Audio K5 Pro" is selected as the audio output device in your system settings.
- Test with different headphones or speakers to rule out issues with the output device.
- Microphone Not Working:
- Ensure your headset's microphone is connected to the correct 3.5mm microphone input on the K5 Pro, especially if using the included splitter.
- Verify "Fosi Audio K5 Pro" is selected as the input device in your computer or PS5 sound settings.
- Check microphone privacy settings on your operating system.
- Test with another microphone if possible.
- Distorted or Poor Sound Quality:
- Check if the input source audio quality is high.
- Ensure all cables are fully inserted and not damaged.
- Adjust the Bass and Treble control knobs to neutral positions or to your preference. Excessive boosting can cause distortion.
- Reduce the volume from the source device or the K5 Pro if the sound is clipping.
- If using USB, try a different USB port on your computer or a different USB cable.
- Device Not Recognized by Computer/PS5:
- Ensure the USB cable is securely connected to both the K5 Pro and the computer/PS5.
- Try connecting to a different USB port on your computer/PS5.
- Restart your computer/PS5.
- Ensure the K5 Pro is powered on.
7. Specifications
| Feature | Detail |
|---|---|
| Product Dimensions | 4.4 x 3.7 x 1.2 inches |
| Item Weight | 14.9 ounces |
| Item Model Number | K5 PRO |
| USB Type C Rate | Up to 24 bit/96 kHz |
| Optical/Coaxial Sampling Rate | Up to 24 bit/192 kHz |
| THD (Total Harmonic Distortion) | ≤0.003% |
| SNR (Signal-to-Noise Ratio) | ≥110dB |
| Output Power (16Ω) | 1000mw |
| Output Power (32Ω) | 500mw |
| Output Power (64Ω) | 300mw |
| Output Power (128Ω) | 150mw |
| Output Power (300Ω) | 80mw |
| Compatible Devices | Gaming Console, Personal Computer, Headphone |
| Connectivity Technology | USB, Optical, Coaxial |
| Number of Channels | 2 |
| Operating System Compatibility | Windows, macOS |
8. Maintenance
To ensure the longevity and optimal performance of your Fosi Audio K5 Pro, follow these maintenance guidelines:
- Cleaning: Use a soft, dry cloth to wipe the exterior of the device. Avoid using abrasive cleaners, solvents, or strong chemicals, as they may damage the finish.
- Storage: Store the device in a cool, dry place away from direct sunlight, extreme temperatures, and high humidity.
- Handling: Handle the device with care. Avoid dropping it or subjecting it to strong impacts, which can damage internal components.
- Ventilation: Ensure the device has adequate ventilation. Do not block any ventilation openings.
- Power: Disconnect the power cable when the device is not in use for extended periods.
9. Warranty and Support
Fosi Audio products are designed and manufactured to the highest quality standards. This product is covered by a manufacturer's warranty against defects in materials and workmanship from the date of purchase. Please refer to the warranty card included in your package or visit the official Fosi Audio website for detailed warranty terms and conditions.
For technical support, troubleshooting assistance, or any inquiries regarding your Fosi Audio K5 Pro, please contact Fosi Audio customer service through their official website or the contact information provided in your product documentation. When contacting support, please have your product model number (K5 PRO) and purchase details ready.
Official Fosi Audio Store: Visit the Fosi Audio Store on Amazon
