And here’s more from our Director of Engineering:
Several PS Audio products use Secure Digital (SD) cards for various purposes. The most prevalent use is for updating the firmware in the internal microprocessors.
Earlier PS Audio products (circa 2009-2010) were restricted to using SD cards that had a size limit of 2GB max. More recently, products have been tested with SD cards with up to 8GB capacity. Higher capacity cards may work but have not been tested.
SD cards are designed to be used in many different applications. The PS Audio applications require that the SD memory card be formatted using the FAT16 standard. On a Windows computer, to format an SD card, insert the card into the proper SD card slot, or if your computer does not have one, purchase an SD card reader and connect it to your computer. Now, with the card installed in the reader, find the SD card in your Windows file explorer, and right click it. This will bring up a pop-up. One of the choices will be to format the card. Left clicking Format will bring up another pop-up that allows you to do the formatting. One of the choices in this window is to choose which formatting standard to use. If you have a larger than 4GB SD card, it will say that FAT32 is the default. Click on this pull down menu, and choose FAT instead. Then proceed to format the SD card.
Files you download, or have emailed to you may be either direct, or may be zipped (processed to minimize the size and combine the files all into one). If they are zipped, they will have a .zip extension at the end of the file name. If they are not zipped, the 3 digit extension will say something like .hex, or .cfg, or something similar. If the files are not zipped, you just have to copy them from the source to the SD card. If they have been zipped, you must use a computer program to unzip them.
Your computer may already have an unzipping program installed. You can test this by double clicking the zip file. If you have such a program, the file will start the unzipping program. You then can follow the instructions for this program to unzip the files and copy them to the SD card. If you do not have an unzipping program, you should either obtain one, or ask for the files to be resent to you in an unzipped format.
The PS Audio firmware update process requires that the files be readable directly on the SD card. If you look at the files on the SD card with your file explorer program (Explore in Windows, Finder in Apple), you should see the several files available when you look at the SD card. If instead you see a folder that you have to click on before you see the files, they will not load. In this case, you need to move the files from the folder to the top level of the SD card directory.
If you have trouble copying files to the SD card, take a look at the card itself. On the side of the card you will see a small slider switch. Make sure this switch is in the ‘unlock’ position.