History (adapted from the official Kurzweil history)
Kurzweil has always been on the cutting edge of samplers, and the K2000, K2500, and now the K2600 are extremely popular.

Kurzweil was founded by inventor Raymond Kurzweil, who had developed a revolutionary reading machine for the blind that scans written materials and reads them aloud in a synthesized voice. Musician Stevie Wonder, a customer for the reading machine, challenged Ray Kurzweil to create an electronic instrument that blended the richness of acoustic sound with the control and sound modification of electronics. The Kurzweil engineers then developed the first ROM-based sampling keyboard to successfully reproduce the full complexity of acoustic instrument sounds - the K250. When the K-250 was introduced in 1983, the music industry was astounded by its ability to emulate a piano, strings, choirs, drums and other acoustic instruments with extraordinary accuracy.

Ray, being a genius in his own regard, garnered engineers around him to develop the K150 (additive synthesis machine) and other technologically advanced machines. These machines did not sell well in the popular market, as the K250 did, and mass sales is the key for sales and stability as a profitable company. So Kurzweil manufactured the K1200 and the offshoot rack units, which took ROM-burned samples and played them back. The 24-voice polyphony (huge back then) was very popular, and Kurzweil sold a ton of them.

But the key to Kurzweil’s sampling popularity was the K2000, which improved on the K1200 and implemented a sampling option. Counting on the company’s good reputation for their piano sound, the K2000 gained a loyal following and is still being sold today.

In mid-1990, Young Chang acquired part of the technology and engineering team from the original Kurzweil Music Systems, Inc. Nevertheless, the guts of the company remained in the US and continued improving on the K2000 base, manufacturing other units such as the K2500, master keyboards such as the PC8, and even small rack units like the Kurzweil MicroPiano.

Ray Kurzweil, always the innovator, left the company awhile ago, but he continues in the voice-interpretation field and other pursuits, and is highly regarded as one of the leaders of computer technology today.

Synthesis and File Structure
Kurzweil's were ahead of their time, reading and writing to the DOS disk format from the beginning. At least with floppy disks that is true, but the hard drive/SCSI implementation is a little stranger. Early implementations of the K2000 used a DOS format that was very similar to the actual documented DOS disk format. As a result, depending on how the hard drive was written, if you tried to read it using a PC or Mac, you could either read the drive, see a blank drive, or even have the drive crash the computer! (However, newer versions (K2000 version 3, and all K2500/2600 versions) adhere to the true modern DOS format fully. See the Miscellaneous article "Kurzweil CD-ROM Support" for more information.)

Fortunately, Translator deals with these issues and enables you to read any disk with Kurzweil files on it.

The file format uses the .krz, .k25, and .k26 extensions. All work similarly.

Translating and Building to Kurzweil Format

Since the Fusion is a Bank format, you can convert any format into a new Fusion Bank, or you can insert a conversion into an already existing Bank.

Samples are converted into Alesis's proprietary .afs sample format. The incoming structure is arranged into the Program-Multisample-Sample Fusion structure.

Since there are restrictions on Oscillator-level programming and only 4 Oscillators, somtimes multiple Programs must be created to imitate an incoming Program. Programs like this are prefaced with an asterisk (*) and a Mix is created, which can play mutiple Programs at one time.

Parameter Tolerence can be used to reduce the need for multiple Programs; higher tolerance allows the Translator conversion engine to average programming needs and while the final result will not exactly match in the incoming source, it will be less complicated to deal with. 0% Parameter Tolerance means no averaging will take place, 100% tolerence means the first claim to a parameter will apply to all further ones.

Samples can be stereo in the Fusion.

Translating Out of Kurzweil Format

The Instrument Unit on the Fusion is a Program. A Mix is a Performance type that can define multiple Programs on different or the same MIDI Channels.

Samples will be converted out of the proprietary .afs format and converted into the destination format.

You can also convert an entire Fusion Bank into a Bank-type destination such as SoundFont, Giga, Motif, etc.