Norbert Lehmann was a student of audio engineering when he heard two amplifiers with identical specifications compared side by side. In his words, "one delivered sound, the other one music." He told HiFi Pig that one amp of that era made the musicians sound "as if they had fallen asleep." He went on to build phono stages, the small amplifiers a turntable needs. A record is cut with its bass turned down and its treble turned up, and a phono stage has to boost the cartridge's tiny signal and undo that tilt. Lehmann borrows from the recording studio to do it, with input stages of the kind used in mixing desks and microphone preamps. Matt Bonaccio of SoundStage! Hi-Fi notes that a moving-coil cartridge works much like a dynamic microphone. Arvind Kohli of TNT-Audio found the Black Cube SE so fast on transients that he once checked whether his turntable was spinning at 45 RPM. The Black Cubes suit listeners who want speed and detail left intact.

Start with the Black Cube Statement. Its gain and loading are set with small switches on the bottom plate, and the case is small enough to place right next to the turntable, which keeps the cables short. The Black Cube SE adds a larger outboard power supply, and the SE II adds a bass roll-off filter for smaller speakers. Higher up, the Decade Jubilee shares parts with the flagship Silver Cube, and Bonaccio heard it improve when he swapped his moving-magnet cartridge for a moving-coil. Lehmann recommends spending at least twice as much on the phono stage as on the cartridge. For headphones there is the Linear. Lehmann advises keeping its gain low and the volume knob past 12 o'clock for the best channel balance and the least noise. It drives two headphones at once, and James Michael Hughes of StereoNET found it played his hard-to-drive AKGs about 6dB louder than the headphone amp in his streamer.

Lehmann started the company in Cologne in 1988 and ran it part time while working as an audio technician at a radio station. His first products were electret microphones for students and musicians around Düsseldorf, and a musicians' magazine called Musiker reviewed them in 1989. The Black Cube followed in 1995, and SoundStage! first reviewed it in 1997. Stephen Mejias of Stereophile later wrote that the Black Cubes had gone nearly unchanged since the original. The Silver Cube of 2002 has a case milled from a solid block of aluminum, and the Linear, the company's first headphone amplifier, arrived in 2004. The company says Sennheiser used a large number of Linears to present its high-end headphones at IFA 2005, and that Ortofon took Black Cube Statements in 2006 for final checks in its production. Lehmann told Bonaccio that Bauer Studios, whose engineer recorded Keith Jarrett's The Köln Concert in Cologne in 1975, has used Lehmannaudio products as references since 2017.