Rives Bird of The Absolute Sound admits that his first thought about the Ovation CS 8.3 was "Who in his right mind would try to have a switching power supply, streaming service, and tube topology in the same box?" AVM's all-in-ones put a streamer, DAC, CD drive, preamp and power amp in a single case. The CS models get their power from class D amplifiers, which switch on and off at high speed and waste little energy as heat, so a lot of power fits in a small, cool-running box. AVM's head, Udo Besser, says he chose class D so compact systems could still drive speakers that need a lot of power. In the CS 8.3 a tube stage feeds that amplifier, and Bird heard "fullness in the midrange" alongside solid-state detail and control. Jason Kennedy of Hi-Fi+ found that the music "bears little if any imprint of the amplification technology." AVM suits listeners who want a high-end system in one box in the living room.

The Inspiration CS 2.3 is the place to start. It's AVM's entry-level all-in-one, with a slot-loading CD drive and a phono stage for a turntable, and Sasha Matson of Stereophile found it ran cool enough to stack a turntable on top without hum. It ships with its volume limited to 70%, so raise the limit in the menu, and AVM recommends a wired network connection. The step up is the Ovation line, where Besser says cost is no object. The CS 6.3 and CS 8.3 share the same amplifier, and the 8.3 adds the tube stage. Besser told StereoNET that the tube versions have outsold the transistor ones. The Ovation all-in-ones also have a replaceable DAC module. If you would rather keep separate components, Herb Reichert of Stereophile described the Ovation A 6.2 ME amplifier as "ease with lush detail." Marc Phillips of Part-Time Audiophile reviewed that amp and then the class D CS 6.3, and he found the two "sound remarkably alike."

AVM grew out of a kit. Engineering graduates Günther Mania and Robert Winiarski founded the company in April 1986, after Mania published an assembly manual for a power amplifier that was first sold in kit form. Once the pair began building the amplifier themselves in Malsch, on the edge of the Black Forest, it became the start of a product range. Robert Harley of The Absolute Sound reports that AVM found early success with the M1 mono amplifier, which sold more than 10,000 pairs in Germany alone. For AVM's 30th anniversary the company rebuilt the M1 with modern parts as the Classic 30. The tubes came later, after AVM's American distributor suggested a valve line stage and the team in Germany dusted off an earlier design. Mel Martin of Secrets of Home Theater and High Fidelity called the A 30.3 "the finest sounding integrated amp" he had come across, and Marc Phillips wrote that he "shouldn't have waited so long to check it out."