TOPPING DX3 Pro+
Desktop DAC & Headphone Amplifier
Introduction
Thank you for purchasing the TOPPING DX3 Pro+ USB Desktop DAC & Headphone Amplifier! The DX3 Pro+ is a high-performance decoder with USB, Optical, Coaxial, and Bluetooth inputs, as well as Line Out and Headphone outputs. It supports specifications up to 768kHz/32bit and DSD512. With its minimalist design and LED display, the DX3 Pro+ can function as a high-fidelity DAC/headphone amplifier, a pure decoder, or a pre-amplifier. We believe the DX3 Pro+ will bring you more musical enjoyment. We recommend reading this manual to ensure you can use all its functions correctly.
Package Contents
- DX3 Pro+ Main Unit x 1
- AC/DC Adapter x 1
- Remote Control x 1
- USB Data Cable x 1
- Bluetooth Antenna x 1
- User Manual x 1
- Product Warranty Card x 1
Note: TOPPING product drivers and electronic manuals can be downloaded from http://www.topping.audio/.
Product Basic Attributes
| Attribute | Value |
|---|---|
| Dimensions | 12.0cm x 16.5cm x 4.0cm |
| Weight | 420g |
| Power Supply | DC15V/1A (DC Jack 5.5*2.1) |
| Input Interfaces | USB/OPT/COAX1/COAX2/BT |
| Line Out Output Interface | RCA |
| Headphone Output Interface | 3.5mm Headphone Jack |
| Display | LED |
| Normal Working Power Consumption | <6.0W |
Front Panel
- 1-1: 3.5mm Headphone Jack
- 1-2: LED Display Screen
- 1-3: Remote Control Receiver [remote receiver]
- 1-4: Volume Knob / Multi-function Button [volume knob]
Rear Panel
- 2-1: RCA Single-ended Output Right
- 2-2: RCA Single-ended Output Left
- 2-3: Coaxial Input 2
- 2-4: Coaxial Input 1
- 2-5: Optical Input [optical input]
- 2-6: USB Input [USB input]
- 2-7: Bluetooth Input [bluetooth input]
- 2-8: Power Input (DC15V) [power input]
Display Explanation
- 3-1: Input Signal Indicator (Solid light indicates current input is connected successfully; blinking light indicates it is not connected.)
- 3-2: Gain Indicator
- 3-3: Output Channel Indicator
- 3-4: Digital Display Area
- 3-5: Volume Unit
- 3-6: Decoding Format Indicator
Remote Control
- F-1: Standby [standby]
- F-2: Volume Up
- F-3: Cycle Left Input
- F-4: Headphone Output
- F-5: Filter Setting [filter]
- F-6: Auto Standby [auto standby]
- F-7: Mute [mute]
- F-8: Headphone + Line Out Output
- F-9: Cycle Right Input
- F-10: Volume Down
- F-11: Line Out Output
- F-12: Headphone Gain Setting [gain]
- F-13: Brightness Setting [brightness]
Specifications
DX3 Pro+ DAC Specifications (USB In @96kHz)
| Parameter | Value |
|---|---|
| Output Amplitude | 21.5Vpp @G=H, <2.1uVrms @G=L |
| Noise Floor (A-wt) | <7.0uVrms @G=H, <2.1uVrms @G=L |
| Channel Crosstalk @1kHz | -137dB |
| SNR @1kHz (A-wt) | 122dB |
| Dynamic Range @1kHz (A-wt) | 122dB |
| Frequency Response | 20Hz-20kHz (±0.3dB), 20Hz-40kHz (±0.7dB) |
| Output Level | 2.1Vrms @0dBFS |
| Channel Balance | 0.3 dB |
| Output Impedance | < 0.1Ω |
Supported Specifications
| Input | Supported Formats |
|---|---|
| USB IN | PCM 44.1kHz-768kHz/16bit-32bit DSD DSD64-DSD512 (Native), DSD64-DSD256 (Dop) |
| COAX/OPT IN | PCM 44.1kHz-192kHz/16bit-24bit DSD DSD64 (Dop) |
| BT IN | AAC/SBC/APTX/APTX LL/APTX HD/LDAC |
DX3 Pro+ Headphone Amplifier Specifications
| Parameter | Value |
|---|---|
| Output Power | 1800mW x 2 @32Ω THD+N<0.1% 900mW x 2 @64Ω THD+N<0.1% 250mW x 2 @300Ω THD+N<0.1% |
| Adaptable Impedance | >8Ω |
| Total Harmonic Distortion + Noise @1kHz (A-wt) | <0.00013% @Output=160mW (300Ω) |
| Total Harmonic Distortion 20Hz-20kHz (90kBW) | <0.00020% @Output=160mW (300Ω) <0.0005% @Output=1500mW (32Ω) |
| SNR @MAX OUT 1kHz (A-wt) | 120dB |
| Dynamic Range @1kHz (A-wt) | 120dB |
| Frequency Response | 20Hz-20kHz (±0.3dB), 20Hz-40kHz (±0.7dB) |
| Output Amplitude | 5.5Vpp @G=L |
Operation Instructions
Power On/Off/Standby
Power On: Upon power connection, the device enters standby mode, indicated by a single bright dot on the screen.
Standby/Exit Standby: Long press the front panel knob to enter standby mode. Short press the knob or the standby button on the remote control to exit standby.
Special Note: If the auto-standby function is enabled, the DX3 Pro+ will automatically enter standby if no input is connected or the current input signal is invalid. It will automatically resume normal operation once a valid signal is detected on any input.
Volume Control
Mute and Restore Volume: Press the mute button on the remote control to mute the DX3 Pro+ output. Press the mute button again or adjust the volume to restore the volume.
Adjust Volume: Use the knob on the front panel or the volume up/down buttons on the remote control to adjust the DX3 Pro+ volume. Long pressing the volume up/down buttons will adjust the volume rapidly; exercise caution to protect your hearing.
Input Channel Switching
Press the front panel knob or use the 'Cycle Left Input' and 'Cycle Right Input' buttons on the remote control to cycle through the input channels sequentially.
Output Channel Switching
Double-click the multi-function button on the front panel or use the 'Headphone Output', 'Headphone + Line Out Output', and 'Line Out Output' buttons on the remote control to select the corresponding output channel. The 'Line Out Output' option allows switching between DAC mode and Pre-amp mode.
Settings Menu
Entering the Settings Menu: While the device is in standby, press and hold the front panel knob while powering it on. This will enter the settings menu.
Navigating and Saving Settings:
- Using the Front Panel Knob: Short press the knob to move to the next setting item. Rotate the knob to change the parameter. Long press the knob until "8-8" is displayed on the screen to save the settings.
- Using the Remote Control: Press the volume up/down buttons to move to the previous/next setting item. Press the left/right buttons to change the parameter. Long press the center button until "8-8" is displayed on the screen to save the settings.
Setting Items Description:
1. PCM Filter Setting
| Screen Display | Description |
|---|---|
| F-1 | Steep Filter |
| F-2 | Fast Roll-off |
| F-3 | Minimum Phase Fast Roll-off |
| F-4 | Minimum Phase Slow Roll-off |
| F-5 | Minimum Phase Fast Roll-off |
| F-6 | Linear Phase Slow Roll-off |
| F-7 | Linear Phase Fast Roll-off (Default) |
2. Screen Brightness Setting
| Screen Display | Description |
|---|---|
| L-1 | Brightness: Dim |
| L-2 | Brightness: Medium (Default) |
| L-3 | Brightness: Bright |
| L-A | Brightness: Medium, auto-off after 30 seconds of inactivity. When off, only the current input is displayed. Press any button to wake the screen. (e.g., when input is USB, screen off display: UBB) |
3. Auto Standby Setting
| Screen Display | Description |
|---|---|
| A-O | Enable Auto Standby (Default) |
| A-C | Disable Auto Standby |
4. Output Channel Setting
| Screen Display | Description |
|---|---|
| 0-1 | Line Out Output |
| 0-2 | Headphone Output |
| 0-3 | Headphone + Line Out Output (Default) |
5. Output Mode Setting
| Screen Display | Description |
|---|---|
| m-p | Pre-amp Mode (Volume Adjustable) (Default) |
| m-d | DAC Mode (Volume Not Adjustable) |
Note: In DAC Mode, the Line Out volume is fixed at 0dB, and volume adjustment is ineffective.
6. Gain Setting
| Screen Display | Description |
|---|---|
| GAIN +6dB | Headphone Gain is +6dB (Vrms/FS) (Default) |
| GAIN +19dB | Headphone Gain is +19dB (Vrms/FS) |
7. Bluetooth Switch
| Screen Display | Description |
|---|---|
| BT ON | Bluetooth ON (Default) |
| BT OFF | Bluetooth OFF |
Restore Factory Settings
While the device is in standby, turn the front panel knob counter-clockwise until the entire screen lights up. This will restore the factory settings.
Bluetooth Pairing
When the DX3 Pro+ is switched to BT input, long press the 'Brightness Setting' button for 3 seconds to disconnect the existing Bluetooth connection and force the Bluetooth into pairing mode.
Performance Graphs
The following graphs illustrate the performance characteristics of the TOPPING DX3 Pro+:
Frequency Response
Shows a flat frequency response curve from 20Hz to 20kHz (±0.3dB) and extending to 40kHz (±0.7dB), indicating accurate audio reproduction across the audible spectrum and into the higher frequencies.
FFT Spectrum Analysis
Displays the frequency spectrum analysis at 1kHz. The graph indicates very low levels of harmonic distortion and noise, signifying a clean audio output.
IMD (Intermodulation Distortion)
Illustrates the device's performance when subjected to two different frequencies simultaneously. The results show minimal IMD, confirming clean audio output.
THD vs Frequency
This graph plots Total Harmonic Distortion (THD) against frequency for both RCA Line Out and Headphone Out. It demonstrates that THD remains exceptionally low across the entire frequency range, even at higher output levels.
THD+N vs Power
This graph shows Total Harmonic Distortion plus Noise (THD+N) as a function of output power for the headphone amplifier. It indicates good performance, with distortion levels remaining low even as output power increases.
