Any USB audio decoding device lacking its own battery needs to draw power
from your iPhone to function. However, the output current of the iOS device has restrictions, so the chip can’t function optimally in most cases. However, if you can connect the external power supply concurrently, circuit power is improved along with sound quality.
An OTG adapter is required when connecting your iPhone to a USB-C audio decoding device. Thanks to TC28i Pro's efficient side port design, the adapter won’t be excessively long or easily broken while connected, especially when using the device with live broadcasts or video recording when connected to a recording platform and/or power.