This is just a quick audio comparison between the Fifine K688 and the Fifine AM8. According to information these both have the same internals but the only difference is the shell. In this recording it only has USB mode. I didn't use XLR mode. They definitely do sound quite different from each other though they do have some similarities. Imo the K688 has a bit more of a wooly characteristic to its tone whereas the AM8 has a more V-shaped synthetic tone to it.