Yamaha, having already been working on physical modelling synthesis for a number of years, released the AN1x in mid-1997.

The VCOs, VCAs, VCFs, and LFOs etc., are all digitally modelled and rendered using DSP VLSI processor(s).

Sequential's founder, Dave Smith subsequently became President of DSD Inc., a research and development division of Yamaha.

[6] The user can either quickly switch between the two Scenes, or morph between them, which interpolates individual parameters, rather than simply crossfading.

In polyphonic mode, Unison is only possible for single voices, each key takes two notes, of the same timbre, one from each of the two processors.

[6] The voice architecture is based on a dual oscillator design with multi-mode filter.

The step sequencer can be used to send control data, such as filter cutoff values or notes to the synthesizer's tone generator or to MIDI output.

The 'Free Envelope Generator' (Free EG) is a powerful motion control feature that allows the user to record controller movements for up to four parameters, '4 tracks, 1 parameter per track' for a duration of up to 16 seconds each, or 8 bars that are tempo linked.

[6] Note: If the tempo is set to 40bpm, with a 4/4 count, this would result in 48 seconds of recording time per track.

The 14 variation effect types are: Chorus, '2 types', flanger, symphonic, phaser, auto pan, rotary speaker, pitch change, aural exciter, compressor, wah, distortion, overdrive and amp simulator.

[6] As well as promoting its "Analog Physical Modelling", Yamaha referred to the AN1x as a "control synthesizer", in a similar vein to the CS1x and CS2x.

The underlying philosophy of this arrangement is that the user doesn't have to alter the actual sound editing parameters whilst playing, instead using the assignable real-time controls mentioned above.

The eight realtime control knobs can also be pressed to display their current parameter values.

Consequently, the user will sometimes hear slight but distinct stepping of the filter, especially when more pronounced resonance is used.

However, there are several workarounds: The first is to press the control knobs while rotating them to access smoother increments, but over a narrower frequency range.

The result being a smoothing out of the filter sweep, therefore giving a more authentic analog feel.

[9] The keyboard's main housing is made of ABS plastic, and the chassis base is metal.

[11] The AN1x has been used by numerous artists, including: Jean Michel Jarre, Psyclon Nine, History Of Guns, Velvet Acid Christ, Nine Inch Nails, Nitin Sawhney,[12] Phish,[12] Igor Khoroshev of YES,[12] Steve Hillier of Dubstar, Jacob Thiele of The Faint,[12] 808 State, Antti Pouta of Pariisin Kevät, Above & Beyond,[12] Jesper Anderberg of The Sounds, Daniel Ruppar of Down In The Lab/One Chord Till Anarchy, and Boards of Canada.