The SFZ file format is used to define instruments in a way that is understood by software samplers from different developers. The SFZ standard was first developed by Cakewalk. A complete specification of the SFZ file format and the opcodes used to define instruments can be found on the Cakewalk DevXchange.

What are SFZ files?

SFZ files are plain text files with a ‘.sfz’ file extension. The files contain ‘opcodes’ that determine how samples will be mapped across a standard MIDI keyboard, how each note will respond to velocity, and other attributes such as placement in the stereo field and tuning. The minimum requirements for creating or editing SFZ files are Textedit (Mac) or Notepad (Windows).

Creating your own SFZ files

Several methods may be used to create new SFZ files:

• Create a new file using a text editor
• Modify an existing SFZ file to suit your needs
• Use SFZ editor software
• Convert an existing sample library using a special utility
• Use a scripting language to generate opcodes based on the contents of a folder

Note: see the SFZ page on the Camel Audio website for more information about the tools available for this purpose. In this manual we will focus on the specifics of the SFZ format relating to Alchemy and Alchemy Player.

The simplest of these methods is to copy an existing SFZ file and modify the referenced file names while taking care to ensure the key and velocity zones are correct for the desired mapping.

Creating a new SFZ file from a blank file using a text editor is practical for smaller instruments, or when combined with copy & paste and find & replace techniques for larger instruments.

Opcodes recognised by Alchemy

The following table lists the opcodes understood by Alchemy.

Note: other opcodes not listed here may be present in an SFZ file. For example, after converting a sample library from some other format to SFZ. These opcodes will be ignored in the current version of Alchemy, and will not have any effect on the playback of the instrument.