Does FIFINE SC3 support USB mics?
USB mics are built to get rid of an external sound card, and a large part of what you paid for a USB mic is for its built-in sound card. There's no necessity to bypass the internal one and spend the extra on external ones, like this SC3.
Is SC3 compatible with XLR mics that use either XLR or 6.35mm connectors?
Yes, SC3 has an XLR combo 6.35mm port, so you can use either an XLR or a 6.35mm mic with it.
But note that:
1️⃣ Since XLR condenser mics need 48V power through the XLR connector, please make sure you use the XLR to XLR cables(not included) for connection.
2️⃣ SC3 audio mixer provides 50dB gain, so when you use a dynamic mic that needs more than that, and you think the audio is a bit low, you may need a cloud lifter to boost the gain.
Does it come with an XLR to XLR cable, or any cables with an XLR end to the other end?
No, we're sorry that this FIFINE SC3 audio mixer comes with the type-C to type-C & a combo cable and a 3.5mm to 3.5mm cable.