Which products support USB output?
JUST MIXER 2, JUST MIXER 5, JUST MIXER M, JUST MIC IV, LOOP8, drum mix.
Why is there a problem with power supply noise?
It is recommended to use the officially USB Adaptor or use the battery to reduce external noise interference. (If you don’t have a USB Adaptor, you can buy it separately)
Are there any products that support Microphone?
JUST MIC IV, JUST MIXER M, MIC POWER, LOOP 8, drum mix.

 
How to reduce and limit any additional static noise:
1) If you want to increase volume, first increase the volume setting on your input 
 device while keeping volume and Gain settings on the mixer on low, then gradually increase volume and Gain settings accordingly. Make sure the red OVER LED isn't glowing, which indicates the mixer is clipping.
2) Make sure you are using fresh, top quality batteries. Rechargeable batteries may not have enough voltage to correctly power the mixer. Whenever possible, power the mixer with USB power from a quality phone charger.
3) Due to certain cables being less noise resistant, you may hear additional static noise due to interference when an input audio cable or USB power cable is plugged into a device or power bank with other charging cables plugged in (i.e computer as input source with a smartphone plugged into USB port close to the stereo audio output).