1. Introduction
The KGUSS DAC-K3 is a versatile Mini HiFi Digital-to-Analog Converter (DAC) and Headphone Amplifier designed to enhance your audio experience. It features multiple input options including Optical, Coaxial, and USB, allowing connection to various digital audio sources. The integrated headphone amplifier provides high-quality sound output for headphones, while RCA outputs enable connection to external amplifiers or active speakers.
Image: Front view of the KGUSS DAC-K3 unit.
2. Safety Instructions
- Ensure the power adapter voltage matches your local power supply to prevent damage.
- Do not expose the device to water, moisture, or extreme temperatures.
- Avoid disassembling the unit. Refer servicing to qualified personnel.
- Keep the device away from strong magnetic fields.
- Unplug the power adapter during lightning storms or when unused for extended periods.
3. Package Contents
Please check the package for the following items:
- KGUSS DAC-K3 Unit x 1
- Power Adapter (DC12V) x 1
- USB Cable x 1
- 6.35mm to 3.5mm Headphone Adapter x 1
- User Guide x 1
- Certificate of Conformity x 1
Image: Contents included in the KGUSS DAC-K3 package.
4. Product Overview
4.1 Front Panel
Image: Front panel of the DAC-K3 with labeled controls and indicators.
- Power Light: Indicates power status.
- Power Switch: Turns the unit on or off.
- Coaxial Light: Illuminates when Coaxial input is selected.
- Optical Light: Illuminates when Optical input is selected.
- Audio Signal Input Switch Button (SELECT): Cycles through available input sources (Coaxial, Optical, USB).
- USB Light: Illuminates when USB input is selected.
- 6.35mm Headphone Output Interface (PHONE): Connects to headphones.
- Volume Adjustment Knob (VOL): Controls the output volume for both the headphone output and the RCA output.
4.2 Rear Panel
Image: Rear panel of the DAC-K3 with labeled input and output ports.
- PC-USB IN: Connects to a computer. Supports OTG for mobile phones, requiring a compatible OTG adapter cable (Type-C/Android/Apple).
- Optical Fiber Input (AUDIO IN): Connects to devices with optical output, such as TV set-top boxes, DVD players, or VCD players.
- Coaxial Input (AUDIO IN): Connects to devices with coaxial output, such as TV set-top boxes, DVD players, or VCD players.
- RCA Output (AUDIO OUT): Connects to a power amplifier, tube amplifier, or active speakers.
- Power-IN (DC12V): Connects to the provided DC12V power adapter. Ensure the voltage does not exceed 12V, the current is more than 1A, and the adapter has an inner positive and outer negative pole (outer diameter 5.5mm, inner diameter 2.1mm).
5. Setup
Follow these steps to set up your KGUSS DAC-K3:
- Power Connection: Connect the provided DC12V power adapter to the Power-IN port (M) on the rear panel and then plug it into a power outlet.
- Input Source Connection: Choose your desired digital audio input:
- For USB input, connect a USB cable from your computer to the PC-USB IN port (I).
- For Optical input, connect an optical cable from your source device to the Optical Fiber Input port (J).
- For Coaxial input, connect a coaxial cable from your source device to the Coaxial Input port (K).
- Output Connection: Connect your audio output device:
- For headphones, plug your 6.35mm headphones directly into the Headphone Output Interface (G). If your headphones have a 3.5mm jack, use the provided 6.35mm to 3.5mm adapter.
- For external amplifiers or active speakers, connect RCA cables from the RCA Output ports (L) to your audio system.
Note on Headphone Priority: When both headphones and RCA outputs are connected, the headphone output takes priority. If headphones are unplugged, the sound will automatically switch to the RCA output. The volume knob adjusts both RCA output and headphone output levels.
Image: The DAC-K3 in a typical setup, demonstrating the headphone priority feature.
6. Operating Instructions
- Power On: Press the Power Switch (B) on the front panel. The Power Light (A) will illuminate.
- Select Input: Press the SELECT button (E) to cycle through the available input sources: Coaxial (COA), Optical (OPT), and USB. The corresponding indicator light (C, D, or F) will illuminate to show the active input.
- Adjust Volume: Rotate the Volume Adjustment Knob (H) clockwise to increase volume and counter-clockwise to decrease volume.
- Mute Function: Pressing the Volume Adjustment Knob (H) may mute the audio output. Press it again to unmute.
- Power Off: Press the Power Switch (B) again to turn off the unit.
7. Internal Components and Features
The KGUSS DAC-K3 incorporates high-quality components for optimal audio performance:
- OPA2134PA: A classic audio operational amplifier known for its mellow, round, neutral, and warm tone, often associated with a 'tube sound' characteristic.
- NE5532P: A high-performance, low-noise operational amplifier, praised for its fidelity and warm tone in the audio industry.
- Other key components include CM6642, CS8416, CS4398, TPA6120A2, UPC1237, an active crystal oscillator, and relays for signal switching.
Image: Close-up view of the OPA2134PA and NE5532P operational amplifiers.
Image: Diagram highlighting various internal components on the circuit board.
8. Maintenance
- Cleaning: Use a soft, dry cloth to clean the exterior of the unit. Do not use liquid cleaners or abrasive materials.
- Storage: Store the device in a cool, dry place away from direct sunlight and excessive dust when not in use.
- Ventilation: Ensure proper ventilation around the unit to prevent overheating.
9. Troubleshooting
- No Power:
- Check if the power adapter is securely connected to the unit and the power outlet.
- Ensure the power outlet is functional.
- Verify the power switch is in the 'ON' position.
- No Sound Output:
- Confirm the correct input source is selected (Coaxial, Optical, or USB) and its indicator light is on.
- Check all audio cables (input and output) for secure connections.
- Increase the volume using the Volume Adjustment Knob.
- If using headphones and RCA output simultaneously, remember that headphone output takes priority. Unplug headphones to enable RCA output.
- If the volume knob was pressed, ensure the unit is not muted.
- Distorted Sound:
- Check the quality of your input audio source and cables.
- Ensure the volume is not set too high, causing clipping or distortion.
- Verify that the 6.35mm to 3.5mm headphone adapter (if used) is fully and correctly inserted.
- Loose Optical Input Connection:
- If the optical cable feels loose, try a different optical cable to ensure a secure connection.
- Audio Delay with TV Optical Output:
- Some TVs may introduce a slight audio delay when using optical output. This is a characteristic of the TV's processing and not a fault of the DAC-K3.
10. Specifications
| Brand | KGUSS |
| Model | DAC-K3 |
| Mounting Type | Coaxial, Plug Mount |
| Interface Type | Coaxial, USB, Optical |
| Main Chipset Material | TPA6120 (Amplifier) |
| UPC | 796862038076 |
| Manufacturer | KGUSS |
| Package Dimensions | 10.98 x 9.53 x 3.03 inches |
| Item Weight | 1.32 pounds |
| ASIN | B07QTXPWVK |
| Date First Available | April 18, 2019 |
Image: Dimensional drawing of the KGUSS DAC-K3 unit.
11. Warranty and Support
The KGUSS DAC-K3 comes with a standard manufacturer's warranty. Please refer to the warranty card included in your package or contact your retailer for specific warranty terms and conditions.
For technical support, troubleshooting assistance, or further inquiries, please visit the official KGUSS website or contact their customer service department through the retailer where the product was purchased.
