Yamaha AN1x, produced by Yamaha Corporation from 1997 to 1998, is a DSP-based analog modeling synthesizer (a.k.a. virtual analog synthesizer) and was marketed as an “analog physical modeling control synthesizer”. It lets you record real-time editing and filtering and be able to store it as part of the sound! A major contender in the new wave of analog-digital synths using DSP modeling of analog waveforms to recreate the coveted sounds of analog synths with modern digital specifications. The AN1x is one of the most affordable physical modelling synths on the market — and it’s no less than 10-note polyphonic, with a host of features designed to bring out the control freak in you.
According to several user reviews, they have praised a Yamaha An1x for the ‘Analogue’ sounds and more — you forget it’s digital; 10-note polyphonic; 61-note keyboard with aftertouch; Neat arpeggiator and sequencing; MIDI Thru; Editable effects. Also, some users have complained it for the user interface is not ‘one knob/switch per function’; External power supply; No computer MIDI interface; Way too affordable.
Image source: wikipedia.org
To restoring your Yamaha An1x to it’s factory settings, first power on while simultaneously holding the ,  and  in the PROGRAM CHANGE keypad until the “Fact Set? [1-9]” appears on the display. Press the number on the PROGRAM CHANGE keypad ( ~ ) corresponding to the factory data set you want to recall.
You can choose from the following factory sets:
- 1-64 voice (loads voices 1-64)
- 65-128 voice (loads voices 65-128)
- all voice (loads all 128 voices)
- sorted voice (loads all voices sorted by voice Category)
- 1-64 user pattern (loads User Patterns 1-64)
- 65-128 user pattern (loads User Patterns 65-128)
- all pattern (loads all User Patterns)
- system (loads system data)
- all (loads all voice, User Pattern and system data)
To execute the factory reset, press [YES/ENTER] button.
Warning! When you execute “Factory Reset”, all stored settings will be erased and returned to the factory settings. Before you perform this operation, check whether there is any data you want to keep. Hopefully the article of “Restore the Yamaha An1x Synthesizer to it’s Factory Settings” can help you.
Reference: Yamaha An1x manual