Don't laugh! Firewire is still a thing, at least to some people. This Focusrite Saffire PRO 14 works great. It features 4 inputs, with two of them up front on combo XLR/1/4" jacks; 4 outputs, a headphone out with volume, and a separate monitor volume. The 2 front inputs have gain adjustment and input LEDs, as well as available phantom power.
On the back are the 2 remaining line inputs, 4 line outputs, MIDI in and out, and SPDIF in and out.
I tested the interface with a firewire 400/800 converter cable, going into a 2012 13" MacBook Pro running El Capitan (OS 10.11.6).
Saffire Mix Control 3.7 was downloaded from the Focusrite site. The video shows various volume, panning, and muting changes to a stereo input.
I did not test on a Windows computer.
The Saffire is in very good shape, with only some scratches and scuffs. A hefty aftermarket power supply is included, along with a regular firewire cable, a firewire 400/800 cable, and a 6 pin/4 pin firewire cable (mainly used for Windows machines, I think).
If you've got the right computer, the PRO 14 is a solid, reliable interface!
A short demo can be seen here - https://reverb.com/item/93118744-focusrite-saffire-pro-14-firewire-audio-interface-w-cables