Kurzweil K250 - History

History

In 1982 Stevie Wonder asked Raymond Kurzweil if "we could use the extraordinarily flexible computer control methods on the beautiful sounds of acoustic instruments?" In response to this query, Raymond Kurzweil made use of fundamental sampling concepts that had originally been exploited in reading machines for the blind (such as the Kurzweil Reading Machine) and adapted them for musical purposes. Reading machines work by sampling characters found in a document or text of some sort at pre-programmed intervals to reproduce a usable image of a document without any noticeable loss in intelligibility. The reading machine then converts the image into data (computing), stores the data onto Random Access Memory (RAM) and/or Erasable Programmable Read-Only Memory (EPROM) and presents the finished product as spoken text via a text to speech synthesizer. The Kurzweil K250 utilizes a similar concept: Sounds are sampled, converted into digital data, stored onto Read-Only Memory (ROM) and are reproduced as sound. A prototype of the Kurzweil K250 was manufactured for Stevie Wonder in 1983. It featured Braille buttons along with sliders (potentiometers) for various controls and functions, an extensive choice of acoustic and synthesized sounds to choose from, a sampler to record sounds onto RAM and a music sequencer utilizing battery-backed RAM for compositional purposes. During production of the Kurzweil K250 at least five units were manufactured for Stevie Wonder.

The Kurzweil K250 was officially unveiled to the music industry during the 1984 Summer NAMM trade show. Shortly thereafter the Kurzweil K250 was commercially manufactured until 1990 and was initially available as an 88-key fully weighted keyboard and as an expander unit without keys called the Kurzweil K250 XP. A few years later into production a rack mount version called the Kurzweil K250 RMX a.k.a. K250 X also became available.

The Kurzweil K250 is generally recognized as the first electronic instrument to faithfully reproduce the sounds of an acoustic grand piano. It could play up to 12 notes simultaneously (also known as 12-note polyphony by utilizing individual sounds as well as layered sounds (playing multiple sounds on the same note simultaneously, also known as being multitimbral). Up to that point in time the majority of electronic keyboards utilized synthesized sounds and emulated acoustical instrument sounds created in other electronic instruments using various waveforms produced by oscillators. Five other manufactured digital sampled sound musical instruments were available at that time: E-mu Corporation's E-mu Emulator and E-mu Emulator II; Fairlight Corporation's Fairlight CMI; and New England Digital's Synclavier I and Synclavier II. However, there were major differences between the Kurzweil K250 and these other instruments:

• The acoustic piano sound contained in and produced by the Kurzweil K250 was so realistic tests were conducted with listeners blindfolded to differentiate sonic differences between a 9-foot Steinway grand piano playing and the Kurzweil K250 playing. Both were played through the same high quality $40,000 US dollar sound system. According to Kurzweil, "There was general agreement that it was not possible to tell the difference between the piano and the K250." This was achieved despite the fact that the sounds in the Kurzweil K250 are 10-bit sampled sounds and utilized a proprietary sound contouring model to reduce memory requirements.

• The Kurzweil K250 could be played as a solo instrument, as an instrument in a band, musical ensemble or in an orchestra. It could also be played as any of these musical groups. Because of this capability, the instrument was one of the first to be used as a Virtual Orchestra.

• Expanding upon this concept a new technology at the time, MIDI Musical Instrument Digital Interface, multiple units and/or other MIDI capable devices could be connected (in a daisy chain fashion) and played together simultaneously or separately. MIDI is utilized to transmit and receive other messaging in controlling other MIDI devices as desired. For example, if twelve Kurzweil K250's were connected together up to 144 notes could be played simultaneously, more than a typical symphony orchestra could typically produce simultaneously with all members playing at any moment.

• SCSI technology is utilized in its system architecture, which was the fastest data transfer technology available at the time.

• It utilized a Motorola 68000 32-bit 10 MHz processor, which was one of the fastest processors available at the time.

• With the sampling option a sound could be sampled up to 50 kHz. (Such a high sampling rate, much higher than the highest frequency humans can hear, is needed because samples of sound at a given rate can represent at best half that audio frequency; see Nyquist frequency.)

• The pitch of a sound could be transposed (see: transposition (music)) up or down using five different transposition modes without much change in timbre, as long as the transposition was not more than a few semitones.

The Kurzweil K250 was highly engineered. For example, the J12 connector on the back of the Kurzweil K250 where the power pod connects to the unit is similar to connectors used in the NASA Space Shuttle. It has hi and low current/voltage rated pins and a lock ring on a collar with a barrel connector. Other details, such as an array of multiple output options, a click track, a sync source (for synchronizing music with another device), an analog output board that produced inaudible noise levels with the widest amplitude (see envelope (disambiguation)) available (even at maximum volume), multiple sliders to assign multiple functions, the sampler previously mentioned and a twelve-track sequencer with advanced functionality were all state-of-the-art at the time of production.

The Kurzweil K250 was initially priced at $10,715 plus options (in 1983 U.S. dollars). Memory (Computer data storage) along with costs in designing, engineering, research and development of such a revolutionary product contributed to this cost. Those who could afford the Kurzweil K250 enjoyed a musical composition, MIDI composition and performance instrument unparalleled to any other at the time. An Apple Macintosh computer typically could be connected to the instrument for sound contouring/sound modeling (see Sound synthesis) and musical compositional purposes. Almost 4,000 units were manufactured.

In the latter years of production two related instruments were also manufactured:

• The Kurzweil K225 RMX. The Kurzweil K225 RMX was similar to the Kurzweil K250 RMX and it was more affordable. The Kurzweil K225 RMX contained about half of the sounds available on the Kurzweil K250 and utilized early production Kurzweil K250 hardware. In some cases a sticker identifying the unit as a Kurzweil 225 RMX was used instead of the standard silk screening imprinting.

• The Hyper Kurzweil K250 or . Very little is known about this model other than the RAM cartridge was relocated to the left front panel, the right front panel possibly had other functionality (unknown), five additional buttons with some sort of SCSI functionality (unknown) were placed above the tuning control, 88 red LED's (Light-emitting diodes) were placed above each key (apparently to light up as the corresponding key was depressed), the manufacturer name KURZWEIL had raised letters instead of imprinted letters on the front panel and the slider caps were different (the slightly rounded edges were squared off). A SCSI hard drive may also have been added below the front right panel area. It is suspected this may have been one of the last Kurzweil K250's developed.

The Kurzweil K250 (with wooden keys manufactured by the Baldwin Piano Company) is heavy and bulky to move; it weighs 95 pounds (plus a few pounds for optional boards and components) and measures 57 inches length x 27 inches width x 9 inches height. The power pod weighs 22 pounds and measures 17¾ inches length x 11⅛ inches width x 4⅛ inches height. The Kurzweil K250 is used today by musicians in recording studios, movie studios, orchestras, ballet/theater companies (see ballet company), colleges/ universities, Bell Labs (the research arm of Alcatel-Lucent), religious organizations, churches and Kurzweil K250 enthusiasts throughout the world.