The Marantz ST-7 is a high-end vintage AM/FM stereo tuner with a built-in oscilloscope, produced around 1980–1982. As part of the prestigious Esotec series, it was engineered for pristine analog radio fidelity and built with a "tank-like" construction, weighing approximately 20 pounds. Today, it remains a coveted item for audiophiles and collectors.

Built-in analog oscilloscope: A central feature that sets the ST-7 apart from many other tuners is its cathode-ray tube (CRT) display. The oscilloscope provides a visual representation of the radio signal, allowing users to precisely monitor and adjust for optimal signal strength, multipath reception, and modulation levels. The ST-7's oscilloscope is square-shaped, distinguishing it from the round one on its sibling, the ST-8.