I use a Playstation 1 memory card, a full size one that cost something like $2 at stores bargain sale, that's the slowest and lowest memory you can get and works just as good as any other high grade SD card. The TRX-2 SD card handling are extremely slow so any card speed will work. But any card I use, even Sandisk 10 or EVO get file corruption when recording files, as there's something not right with the SD card interface. But it's just a couple of recorded files that gets corrupt, cannot be deleted, and a quick format solves it.
/Ubbe