The PSR-I425 lets you load a single User Style, which will be Style Number 163.
(1) The style file must be a SFF1 style file. If you have a SFF2 style file that you want to use, convert it to a SFF1 style file using Jørgen Sørensen's "Style Old Format Converter" program (
http://www.jososoft.dk/yamaha/software/sofc/index.htm).
(2) The style file must not be too large. I'm not certain, but I think the maximum size might be 31,118 bytes, or roughly 30.3 kB. If you have a style file that's larger than 31,118 bytes, you'll need to reduce its size somehow. The first thing to try would be to remove any unusable style sections using Jørgen Sørensen's "Style Remixer" program (
http://www.jososoft.dk/yamaha/software/sremix/index.htm). The following sections are the only ones which are usable, so you can either remove any unusable sections, or if you like them better you can move them to the these sections:
- Intro A
- Intro B
- Main A
- Main B
- Fill In AB *
- Fill In BA *
- Ending A
- Ending B
* The style file can also contain the "Fill In AA" and "Fill In BB" sections, but the panel controls allow you to trigger only two of the four possible "Fill In" sections-- either "Fill In AA" or "Fill In AB" (but not both), plus either "Fill In BA" or "Fill In BB" (but not both). When playing a "Fill In" the panel displays either "Fill A>B" or "Fill B>A" (even if the style file is actually playing "Fill In AA" or "Fill In BB"), so I think it's less confusing to just use the "Fill In AB" and "Fill In BA" sections.
(3) The style file must have the ".STY" file name extension. If the style file's name has a different extension, rename it so that it has the ".STY" extension.
(4) You may also want to use some of Jørgen Sørensen's other programs on the style file, such as "Style Revoicer" (
http://www.jososoft.dk/yamaha/software/revsty/index.htm).
(5) The PSR-I425 does not have a port for attaching a USB flash drive, so you will need to transfer the style file to the keyboard's internal memory using Yamaha's "Musicsoft Downloader" program (
https://usa.yamaha.com/support/updates/msd_win_kbd.html). If you're using an iPad, iPhone, or iPod touch, use Yamaha's "MusicSoft Manager" app (available in the App Store).
(6) After the style file has been transferred to the keyboard's internal memory, follow the instructions on page 74 of the PSR-I425 Owner's Manual to load it as Style Number 163.
If you experience a problem with these procedures, let me know which step it is and what the symptoms are so I can try to help.