Yep, all analog signal inputs are converted to digital in the interface and sent via usb to the computer. Digital signal coming from the computer is then converted to analog in the interface and sent via outputs on the Tascam. There are usb mixers that have converters, but for this instance an analog mixer/preamp is needed to amplify the microphone signal to a level that can be converted. A mic on its own is not enough signal. It needs to be amplified. Same with a guitar.
Some hardware with digital outs would be needed to make use of input 15&16 on the Tascam.
Yep, all analog signal inputs are converted to digital in the interface and sent via usb to the computer. Digital signal coming from the computer is then converted to analog in the interface and sent via outputs on the Tascam. There are usb mixers that have converters, but for this instance an analog mixer/preamp is needed to amplify the microphone signal to a level that can be converted. A mic on its own is not enough signal. It needs to be amplified. Same with a guitar.