Tone 2 Pro exists like current noise which appears in the earphone(only left ear) but not in the headset.
Earphone:REECHO SG01-OVA
Headset: Feaulle Feature
Hi YOKIE,
Could you provide your serial number here？
Please upgrade the v1.41 firmware and try test again.
Note: For v1.0 firmware (serial number starts with 0C: or 11: ), in addition to updating the XMOS firmware, the MCU needs to be updated separately
Hi YOKIE,
Is this earphone(REECHO SG01-OVA) working properly on other devices?
@Eric68 Please check this.
Both of them work well on my smartphone by using cx31993 through type-c interface,so as directly on PC.
The noise is small and only at left.
When playing a song,it disappear.(On PC)
Will it be interfered by my wireless router?
There is no current noise when i connect Tone2 Pro to my smartphone.
But when i pause the music,it makes a popping sound after about 2 second.
Hi YOKIE,
Eric68 will contact you later, he’s on leave for something.
It’s fine,thank you 
Hi
I see the impedance of your headphone is 15ohm,you should enter gain mode to choose low gain mode,then you ought to decrease the volume of it.You can refer to the instruction for the detail operational approach,and have a try.