Originally Posted by
schmidj
The 128 GB number was probably the largest micro SDHC card made when the copy was written, they don't want to say you could add 512 GB if you can't purchase a 512 GB card, deceptive advertising.
I suspect that any (legitimate) SDHC card you can buy will work (that has been my experience with smart phones), but your best bet is to try to find a Sony forum and ask there if anyone has tried what you want to use. Usually once they adopt the standard, (SDHC) it will work with any card properly implementing the standard. At least with audio, speed is not an issue. I have a 256 GB card in my cell phone, full. I'm waiting until the 400 GB cards become a little less pricey.
But obviously, this is only a suspicion on my part, absent trying one or a commitment from Sony, no guarantee!