E50 II

1. Check that the power cord is plugged in securely.
2. Try with another DC5V power adapter.
3. Try with another power cable.

1. The device did not power on. Check the power supply.
2. Check that the proper input source is selected. Press the touch button on front panel to switch input channel.
3. Check the output setting.  Press the "Output Switch" button on the remote control to switch the output channel.

4. Check the connections for all devices.
5. Insert connection cables all the way in.
6. Check the volume of all devices and whether they are muted.
7. Try disabling the PEQ function.
  a, If the PEQ function is enabled and high-sample-rate muting is also active, sampling rates above 192kHz may be muted.
  b, The PEQ gain settings might be too low, especially the pre-gain.
8. Bluethooth IN: Too low volume on phone. Please adjust volume.
9. USB IN: 
  a, Too low volume on PC. Please check and adjust the computer system volume, music player volume and driver volume. 
  b, Select the default output device of your music player or computer as this unit.

10. ADAT fiber optic input (please refer to the instruction manual for details):

1. Try with other songs.
2. The specifications of songs are not supported by this unit.

3. If the noise appears only when playing DSD files, please check and adjust the computer system volume，driver volume and music player volume to the maximum.

4. If you experience distortion after enabling the PEQ function, it may be due to the preamp gain being set too high, causing signal overload. Please try gradually reducing the preamp gain until the distortion disappears completely.
5. Check to see if the problem is with the source, downstream equipment and cables.
6. If the noise disappears after unplugging the USB cable, it may be interference from the source. You could try to add a USB isolation between this unit and the source.
7. This may be caused by input overload on the downstream device. Try reducing the E50 II output level, or enter the settings menu and set the output amplitude to Low.

1. Check  if the PEQ and function is ON. [Setup menu - EQ1/EQ2/EQ3]
2. Check to see if the problem is with the source, downstream equipment and cables.
3. This may be caused by an overload of downstream device input. Try lowering the volume of the E50 II, or go to the settings menu and set the output amplitude to low.

Check to see if the problem is with the source, downstream equipment and cables. You can try swapping the left and right channel connections and try with another source.

1. If the PEQ function is enabled, check whether it is due to different gain settings for the left and right channels.
2. Check to see if the problem is with the source, downstream equipment and cables. You can try swapping the left and right channel connections and try with another source.

1. The device's Bluetooth may already be connected to another device. Use the Bluetooth clear function to disconnect first (press and hold the brightness button on the remote to disconnect Bluetooth); Reconnect via Bluetooth.
2. Bluetooth may not be enabled. Go to system settings and enable Bluetooth.[Menu Settings - BT-ON]
3. Bring the Bluetooth device near to this unit.
4. Power off and restart the unit. On your phone, unpair other devices, restart Bluetooth, and then try to pair again.
5. Try a different phone.

1. Bring the Bluetooth device near to this unit.
2. Remove obstructions between the Bluetooth device and this unit.
3. Check if the problem lies with your phone, other devices, or the cable.
4. To avoid electromagnetic interference, please place this device away from microwave ovens, Wi-Fi routers, and other Bluetooth devices.
5.  Disconnect and reconnect Bluetooth.

1. Check that the proper input source is selected. Short press of the touch button on the front panel switches the input channel.
2. Verify that the USB settings are correct: [Setup Menu - USB audio class].
3. Check whether the USB connection is working properly, and try using a different USB cable. It is recommended to use a USB cable shorter than 1.5 meters.
4. Try connecting to another USB port on the computer. Use a rear USB port on the PC whenever possible, and avoid using USB hubs—especially unpowered ones.
5. Disconnect any unnecessary USB devices from the computer.
6. If the driver is not installed correctly, please reinstall the driver.
7. If the issue persists, it may be related to the computer. Check the PC or try connecting to another one.
8. When connecting to a smartphone, note that some models require manually enabling the OTG function.

1. The remote control has no batteries or low battery. Two AAA batteries are required.
2. The remote control needs to be pointed at the receiver.
3. The remote control function is not enabled on the device. Please enable the remote control function in the settings menu. [Settings Menu - r-O]
4. The remote control may be faulty. Use your Android phone's camera to take a picture of the transmitter on top of the remote control. Check if it flickers when pressed. If not, the remote control is faulty.
5. If there are multiple TOPPING devices, check if the wrong remote control is being used.

1. Bluetooth is not enabled on your device. Please enable Bluetooth in the settings menu. [Settings Menu - BT-ON]
2. Check if Bluetooth is enabled on your phone.
3. Power cycle your device and restart the app. Unpair your phone from other devices, restart Bluetooth, and then try pairing again.
4. Install a Bluetooth antenna.
5. Press and hold the brightness button on the remote to clear Bluetooth, then search and pair again.
6. Check if the APP version and E50 II firmware version are the latest versions. If not, please update them.
7. Try uninstalling and reinstalling the app.

Please check in the settings menu whether it is set to DAC mode.
In preamp mode, the unit's screen displays the volume. When the sampling rate of the input signal changes, the current sampling rate will be displayed, and the volume will resume after 2 seconds. In DAC mode, the unit always displays the sampling rate, maintains maximum volume output, and the volume is not adjustable.

The choice of music player app, the setting of music player and the setting of computer/phone will all have an impact on the sampling rate.
The sampling rate displayed by this unit is the sampling rate of the input signal, and it will not change the sampling rate by itself.
If the music player can be set to exclusive mode, the audio signal will not be resampled by the computer/phone, so the sampling rate of the output signal is the sampling rate of the original file, and the sampling rate displayed by this unit is also the sampling rate of the original file.
Because some players can't be set to exclusive mode, the audio signal will be resampled by the computer/phone and then output. So this unit will always display the sampling rate set by the computer/phone.
We recommend using Audirvana player on MAC OS and Foobar on windows OS.

You need to set the USB audio class in the E50 II's menu settings to UAC1.0 mode for it to work properly.

If you accidentally enter DFU mode, unplug and re-plug the power cable and reboot this unit. Try to re-flash the firmware if DFU is still displayed.

Firmware upgrade in progress, waiting for update to complete.

Firmware update failed. Please try installing the correct firmware again. If the update still fails, enter DFU mode and retry: connect the USB cable to the computer, then to the E50 II USB-C port, and immediately press and hold the touch button for more than 3 seconds until DFU is displayed. If the device is not recognized during the update, try using a different USB port on the computer, a different USB cable, or another computer.

Disconnect other devices and reboot. If the problem still persists, your unit may be defective. Please contact the store where you purchased it.

Indicates a DC output fault. After changing the song or turning down the volume, unplug and re-plug the power cable and reboot the unit. If the problem still persists after disconnecting the other devices and restarting it, the unit may be defective.

Input voltage abnormality. Check if the power supply input voltage is DC 5V. Try replacing it with a different DC 5V power supply.