1. Introduzione
The KGUSS TOPPING DX3pro+ is a high-performance Digital-to-Analog Converter (DAC) and Headphone Amplifier (HPA) designed for high-fidelity audio. It features multiple input options including USB, optical, coaxial, and Bluetooth, along with line out and headphone amplifier outputs. Equipped with an ES9038Q2M DAC chip and XMOS XU208 USB interface, it supports high-resolution audio up to 32-bit/768kHz PCM and DSD512. The integrated NFCA headphone amplifier circuit provides powerful and clean output for various headphones. This manual provides detailed instructions for optimal use.
2. Contenuto della confezione
Verifica che tutti gli articoli elencati di seguito siano inclusi nel tuo pacchetto:
- DX3pro+ Unit
- Adattatore di alimentazione DC15V/1A
- Telecomando
- Cavo USB
- Antenna Bluetooth
- Manuale d'uso
- Scheda di garanzia

Figure 2.1: Contents of the DX3pro+ package.
3. Prodotto finitoview
3.1 Pannello frontale

Figure 3.1: Front panel of the DX3pro+.
- Uscita cuffie da 3.5 mm: Collega qui le tue cuffie.
- Schermo a LED: Displays current status, input, volume, and sampil tasso.
- Ricevitore del telecomando: Per ricevere segnali dal telecomando.
- Volume Knob / Multi-function Button: Rotate to adjust volume; press to switch inputs or enter settings menu.
3.2 Pannello posteriore

Figure 3.2: Rear panel of the DX3pro+.
- RCA Output (Rout, Lout): Right and Left channel single-ended RCA outputs for connecting to an ampdiffusori acustici o attivi.
- Coaxial SPDIF Input (COAX 1, COAX 2): Two coaxial digital audio inputs.
- Optical SPDIF Input (OPTICAL): One optical digital audio input.
- USB Input (USB): Connect to a computer or compatible media player for USB DAC functionality.
- Bluetooth Antenna (ANT): Connect the provided Bluetooth antenna for wireless audio reception.
- Power Input (DC15V): Connect the DC15V/1A power adapter here.
4. Impostazione
4.1 Collegamento di alimentazione
Connect the provided DC15V/1A power adapter to the "DC15V" input on the rear panel of the DX3pro+, then plug the adapter into a power outlet. The device will enter standby mode, and the screen will display a bright spot.
Video 4.1: Demonstrates the power connection and initial setup steps for the DX3pro+.
4.2 Collegamenti di ingresso
Connect your audio source devices to the corresponding inputs on the rear panel:
- USB: Use the supplied USB cable to connect the DX3pro+ to your computer or a compatible media player. Ensure your device supports OTG external sound card functionality if connecting to a mobile phone or tablet.
- Ottico/coassiale: Connect digital audio sources such as CD players, game consoles, or TVs using optical or coaxial cables.
- Bluetooth: Screw the Bluetooth antenna onto the "ANT" connector. Pair your Bluetooth-enabled device (phone, tablet, laptop) with the DX3pro+ to stream audio wirelessly.

Figure 4.1: Connecting the DX3pro+ to a mobile device via USB for high-performance DAC functionality.
5. Istruzioni per l'uso
5.1 Accensione/spegnimento e standby
- Accensione: Connect the power supply. The device will automatically power on and enter standby state, indicated by a bright spot on the screen.
- Stand-by: When the device is working, press and hold the volume knob on the front panel to enter standby state. To exit standby, press the knob again or use the remote control.
5.2 Selezione dell'ingresso
Press the volume knob on the front panel to cycle through available input channels (USB, OPT, COAX1, COAX2, BT). The selected input will be displayed on the screen.
5.3 Regolazione del volume
Rotate the volume knob on the front panel to adjust the output volume. The volume can also be adjusted using the remote control.
5.4 Impostazioni del menu
To enter the setup menu, press and hold the volume knob when the power is off, then power up the unit. Rotate the knob to navigate between settings and press to confirm. Press and hold the knob until "8-8" is displayed to save settings.
- PCM Filter Setting (F-1 to F-5): Adjust PCM filter characteristics.
- Screen Brightness Setting (L-1 to L-3): Regola la luminosità del display.
- Automatic Standby Setting (A-O, A-C): Enable or disable automatic standby.
- Line Out Channel Setting (O-1 to O-3): Select output channel mode (Headphone amp, Cuffia amp + Line out, Line Out).
- Output Mode Setting (m-P, m-d): Select between Pre-amp mode (volume adjustable) or DAC mode (fixed 2Vrms output).
- Cuffia Amp Gain (GAIN +6dB, +19dB): Regola le cuffie amplifier gain for different headphone sensitivities.
- Bluetooth Setting (BT ON, BT OFF): Abilita o disabilita il Bluetooth.
Video 5.1: Demonstrates how to navigate and adjust settings in the DX3pro+ menu.
6. Caratteristiche e specifiche
6.1 Caratteristiche principali
- High-performance DAC with USB, optical, coaxial, and Bluetooth inputs.
- ES9038Q2M DAC chip for high-resolution audio.
- XMOS XU208 for USB input, supporting PCM up to 32-bit/768kHz and native DSD512.
- NFCA headphone amplifier circuit with two gain settings (+6dB, +19dB).
- Bluetooth 5.0 with LDAC, AAC, SBC, APTX, APTX LL, and APTX HD protocols.
- Multiple output modes: Headphone amp, Cuffia amp + Line out, DAC e Pre-amppiù vivace.
- Digital volume adjustment with no channel imbalance.

Figure 6.1: Key features and improvements of the DX3pro+ model.
6.2 Specifiche tecniche
| Specificazione | Valore |
|---|---|
| Marca | KGUS |
| Numero di modello | TOPPING DX3pro+ |
| Dimensioni | 16.5cm L x 12.0cm W x 4.0cm H (6.5"L x 4.72"W) |
| Peso dell'articolo | 420 g (0.93 libbre) |
| Materiale | Alluminio |
| Volume massimo di fornituratage | 15 Volt |
| Tipo di interfaccia | Coaxial, USB, Optical, Bluetooth |
| USB IN (PCM) | 44.1kHz-768kHz / 16bit-32bit |
| USB IN (DSD) | DSD64-DSD512 (Native), DSD64-DSD256 (DoP) |
| COASSIALE/ACCETTAZIONE | 44.1kHz-192kHz / 16bit-24bit, DSD64 (DoP) |
| BT IN | AAC/SBC/APTX/APTX LL/APTX HD/LDAC |
| THD+N @1kHz (peso A) | <0.00015% (RCA Out), <0.00015% (HP Out @1500mW (32Ω)) |
| SNR @1kHz (A-peso) | 122dB (RCA Out), 120dB (HP Out) |
| Output Power (HP Out) | 1800mW x 2 @32Ω THD+N<0.1%, 900mW x 2 @64Ω THD+N<0.1%, 250mW x 2 @300Ω THD+N<0.1% |

Figure 6.2: Comprehensive technical specifications for the DX3pro+.
7. Risoluzione Dei Problemi
This section addresses common issues you might encounter with your DX3pro+ and provides solutions. For more detailed troubleshooting, refer to the official support resources.
Video 7.1: Official troubleshooting guide for the TOPPING DX3pro+.
Problemi comuni e soluzioni:
| Fenomeno | Soluzione |
|---|---|
| Can't be turned on |
|
| Nessun suono |
|
| Riproduzione rumorosa |
|
| One channel with noise/no output |
|
| Channel imbalance |
|
| Impossibile accoppiare Bluetooth |
|
| Bluetooth in: the sound is cut off |
|
| The connected USB device does not recognize this unit |
|
| Il telecomando non risponde |
|
| Le sample rate displayed on the device does not match the music file |
|
| HP -3 |
|
| DFU |
|
| HP ERR |
|
| IN Err / INH Err / INL Err |
|
| giorno-3 |
|
| Can't adjust this unit's volume |
|
8. Garanzia e supporto
KGUSS and HIFI College are committed to customer satisfaction. We offer the following support:
- Garanzia di rimborso di 30 giorni per qualsiasi motivo.
- More than 12-month warranty on all quality defects.
- Supporti 30-day price matching.
- For any questions or support, please contact HIFI College at HIFICOLLEGE@gmail.com.
HIFI College is an authorized distributor for KGUSS, TOPPING, GUSTARD, and FX-AUDIO/xDuoo products, ensuring authenticity and reliable support.
