Privia
The Privia is a line of digital pianos and stage pianos manufactured by Casio. They have 4-layer stereo piano samples and up to 256 notes of polyphony, depending on model. All Privia models feature some kind of weighted keyboard action which simulates the action on an acoustic piano. First introduced in 2003, the Privia was originally designed to be a new competitor to other brands like Yamaha, Roland, and Kawai in budget digital piano products, but since then more exclusive pianos has been added to the line as well. Overview. The original Privia was introduced by Casio in  2003, as a new concept within budget digital pianos, and is widely known for offering more advanced features and high-quality sound at affordable prices, being able to keep up with more expensive instruments. The first Privia was the PX-100. Like any other compact digital pianos, it was able to be played on a table or optional stand, and was equipped with a digital sound source created by independent sampling of various piano timbres. The first generation Privia was produced from 2003 to 2006, and utilizes the Zygotech Polynomial Interpolation (ZPI) synthesis sound engine, as used in Casio's numerous  former flagship keyboards. Second generation follows from 2006 to 2009, using similar sound engine. The third generation was introduced in 2009, featuring an all new Linear Morphing AiF (Acoustic and Intelligent Filtering) sound engine with 4-level dynamic stereo piano sampling and 128-note polyphony. The fourth generation is the current version of the Privia, first introduced in 2012 . It uses the improved rendition of Linear Morphing AiF engine, called Multi-Dimensional Acoustic and Intelligent Resonator (AiR) sound engine, featuring a revamped 4-layer sampling and new features such as simulated sympathetic resonance, adjustable key sensor response (referred to as  Hammer Response), half-damper effect, pedal noises and key-off simulation. Minor update of fourth generation is introduced in 2015, with some models included color touchscreen and improved built-in speaker system, as well as updated various features with few models has up to 256-note polyphony. Keyboard action. As with other digital pianos, the Privia features a fully weighted keyboard action to simulate the action on an acoustic piano. This key action consist of a mechanical system of small "hammers" and weights attached to each keys that will lift up when the key is pressed, while the keys trigger  the sensors to generate sound. The sensors are located in the bottom of the keyboard, similar to that of a synthesizer keyboard action Throughout various incarnations, the key action has undergone several changes over time: Scaled Hammer Action (2003–2008 models). The original keyboard action, featuring a single or double sensors installed below the keybed. The weights are attached far back to the keys, giving it a slight resistance after the keys are released. It is also have a simulated weight in which lower notes are heavier than higher ones. Tri-Sensor Scaled Hammer Action (2009–2011 models). Tri-Sensor Scaled Hammer  utilizes three individual sensors for each keys, two installed below the key's base, and one installed slightly further back near the hammers. The hammers are also modified to have less resistance and swings back faster upon release. The three sensors ensures precision response and improved touch sensitivity compared to its predecessor. Tri-Sensor Scaled Hammer Action II (2012–present models). A revamped incarnation of the previous action. The triple sensors are now installed right below the key's base, while the hammers remain unchanged. Furthermore, this action even features unique keys with simulated synthetic ebony and ivory texture and  the sensor's response can be digitally adjusted to match the playing style realistically. The Scaled Hammer Action II has been described as being harder, more substantial and heavier compared to the previous versions. It is also widely criticized for its characteristic knocking noises when played at medium to high velocities, and considered as being heavier than a generic acoustic piano keys. Smart Scaled Hammer Action (2019–present models). Reduces size and weight without compromising playing feel. Included in PX-S1000 and PX-S3000 models. And the new 2021 models, PX-S1100 and PX-S3100. Models. Models currently sold in  black. Standard models. The CGP-700 includes a unique stand equipped with built-in amplification and speakers. The MXi sound engine was later used for Casio's latest MZ-X series of keyboard/synthesizer hybrid instrument, introduced in early 2016 "Note: the CGP-700" "(2015 model) and PX-A100/A800 Anniversary series (2013 model) was offered only in Japan and Western markets, and not available in other regions."