The first group, lasting from introduction to 1977, had ground stainless steel reeds, a pick-up using variable capacitance, and leather-faced activation pads.

The second group from 1977 until the end of production used rolled spring-steel reeds, electro-magnetic pick-ups, and moulded silicone rubber activation pads.

The Hohner Pianet is an electro-mechanical instrument, and needs to be connected to an amplifier to produce an audible sound.

The resulting sound has a complex mixture of harmonics when the reed is first struck, which later reduces to a cleaner sustained tone.

[5] Zacharias became interested in keyboard instruments such as the clavichord, harpsichord and organ as a teenager, and studied electrical engineering at the University of Kiel.

The most popular model, the Pianet N (denoting "natural wood finish"), evolved through two different specifications.

[5] The Pianet soon found popularity with music groups of the 1960s, including the Beatles, the Zombies and Manfred Mann.

[11] Specific manufacturing dates are difficult because of undated sales figures and a lack of consistent worldwide availability.

The word 'Pianet' appears in gold facing upward on the left hand end of the music support ledge.

It has a gold hammertone painted aluminum fascia panel below the keys with a lock fitted centrally.

The word 'Pianet' or 'Pianet C' appears in gold facing upward on the left hand end of the music support ledge.

Approximate manufacturing span 1963–1968 The Pianet L has a stepped rectangular case side profile with no lid.

It has tapered rectangular cross-section legs forming an inverted 'V' that mount to the ends of the case and are secured by a large, threaded knob.

It has a gold hammertone painted aluminum fascia panel below the keys with a lock fitted centrally.

It has a gold hammertone painted aluminum fascia panel below the keys with a lock fitted centrally.

It has tapered rectangular cross-section legs forming an inverted 'V' that mount to the ends of the case and are secured by a large threaded knob.

Approximate manufacturing span 1977–1983 The Pianet T introduced a very innovative electro-mechanical system where by vibrating reeds are plucked by plastic suction pads (patented by NASA).

The Pianet T has a rectangular case profile with rounded corners and a hinged integral lid with central handle.

The body of the case is covered with black vinyl leathercloth and the ends are padded with vinyl-skinned urethane foam.

The Duo has a rectangular case profile with rounded corners and a removable lid to protect the keys and control surface for transport.

In the glam rock era, the Pianet was used by Bryan Ferry on the first few Roxy Music albums, for instance featuring prominently in their hit "Editions of You".

It was a staple of the "classic lineup" sound of Curved Air (1970–1972), featuring prominently on their first 3 albums, played by both guitarist/keyboardist Francis Monkman and violinist Darryl Way.

The 1972–74 lineup of progressive rock pioneers King Crimson used a pair of Pianets in live performance, played both by the group's violinist David Cross, and the guitarist, Robert Fripp[1].

Genesis keyboardist Tony Banks used the Pianet prominently in the group's early career, as a lead instrument through a homemade fuzz box.

It is also popular as a substitute for the Fender Rhodes or Wurlitzer electric piano, which has a related reed-based mechanism for generating sound but is typically much heavier, requires more maintenance than the Pianet, and is overall more expensive.

Following the end of production, replacement parts for Pianets became progressively harder to find because they were no longer being supported by Hohner.

The principal problem was the activation pads for 1960s-manufactured models, which used a Urethane foam damper behind the leather surface.

Hohner intended the pads to be a service-replaceable item (like the strings of a guitar), and sold spares while the instrument was in production.

In the 2000s, a number of businesses took up the servicing and maintenance of vintage keyboards, so pads suitable for both groups of Pianets are now available.