Do you mean you've converted your SG/MY 1350 to US FW V6.20, or do you have an original US unit you've upgraded to V6.20? US/EU firmware cannot use ANY Asian JCV file, even if the file's patched, Asian fw can use another Asian region's JCV if patched. See: [Only registered and activated users can see links. ]. Read also Post #29 for compatibility.

If it's an original US device, you can load modded fw to use the ID voice. See this thread, Post #22: [Only registered and activated users can see links. ]. But as said, can't see any Asian JCV with a US fw device. If it's SG/MY device it can use the ID voice and see patched ID jcv files.