The Ensoniq ES-5506 "OTTO" was a 32 voice wavetable oscillator chip used in implementations of wavetable synthesizers

Wavetable synthesis

Wavetable synthesis is used in certain digital music synthesizers to implement a restricted form of real-time additive synthesis. The technique was first developed by Wolfgang Palm of PPG in the late 1970s and published in 1979, and has since been used as the primary synthesis method in...

. Musical instruments and PC sound card

Sound card

A sound card is an internal computer expansion card that facilitates the input and output of audio signals to and from a computer under control of computer programs. The term sound card is also applied to external audio interfaces that use software to generate sound, as opposed to using hardware...

s were the most popular applications.

OTTO is capable of altering the pitch

Pitch (music)

Pitch is an auditory perceptual property that allows the ordering of sounds on a frequency-related scale.Pitches are compared as "higher" and "lower" in the sense associated with musical melodies,...

 and timbre

Timbre

In music, timbre is the quality of a musical note or sound or tone that distinguishes different types of sound production, such as voices and musical instruments, such as string instruments, wind instruments, and percussion instruments. The physical characteristics of sound that determine the...

 of a digital recording, and is capable of operating with up to 32 channels at once. Each channel can have several parameters altered, such as pitch, volume, waveform, and filtering

Digital filter

In electronics, computer science and mathematics, a digital filter is a system that performs mathematical operations on a sampled, discrete-time signal to reduce or enhance certain aspects of that signal. This is in contrast to the other major type of electronic filter, the analog filter, which is...

. The chip is a VLSI

Very-large-scale integration

Very-large-scale integration is the process of creating integrated circuits by combining thousands of transistors into a single chip. VLSI began in the 1970s when complex semiconductor and communication technologies were being developed. The microprocessor is a VLSI device.The first semiconductor...

 device designed to be manufactured on a 1.5 micrometre double-metal CMOS

CMOS

Complementary metal–oxide–semiconductor is a technology for constructing integrated circuits. CMOS technology is used in microprocessors, microcontrollers, static RAM, and other digital logic circuits...

 process. It consists of approximately 80,000 transistor

Transistor

A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...

s. It was part of the fourth generation of Ensoniq audio technology.

Major features:

• Real time digital filters
• Frequency interpolation
• 32 independent voices
• Loop start and stop positions for each voice (bidirectional and reverse looping)
• Motorola 68000
  Motorola 68000
  The Motorola 68000 is a 16/32-bit CISC microprocessor core designed and marketed by Freescale Semiconductor...
  
   compatibility for asynchronous bus communication
• Separate host and sound memory interface
• At least 18-bit accuracy
• 6 channel stereo serial communication port
• Programmable clocks for defining serial protocol
• Internal volume multiplication and stereo panning
• A to D input for pots and wheels
• Hardware support for envelopes
• Support for dual OTTO systems
• Optional compressed data format for sample data
• Up to 16 MHz operation

Implementations of OTTO:

• Ensoniq Soundscape S-2000
  Ensoniq Soundscape S-2000
  Soundscape S-2000 was Ensoniq's first direct foray into the PC sound card market. The card arrived on the market in 1994. It is a full-length ISA digital audio and wavetable synthesis device, equipped with a 2 MiB Ensoniq-built ROM-based patch set...
  
  
• Ensoniq Soundscape Elite
  Ensoniq Soundscape Elite
  The Soundscape ELITE was Ensoniq's high-end ISA PC sound card offering. It offers the highest MIDI quality of any PC sound card Ensoniq produced. The board is an evolution of the company's previous Soundscape S-2000. The Soundscape ELITE was launched in March 1995....
  
  
• Ensoniq SoundscapeDB
  Ensoniq SoundscapeDB
  The SoundscapeDB is an Ensoniq-designed and produced MIDI daughtercard designed to interface with the "Waveblaster" header available on many older sound cards. It was released in 1994....
  
  daughterboard