Sure Electronics TK2050 amplifier

A stereo HiFi amplifier based around a TK2050 board from Sure Electronics.

These so called 'Class T' amp boards using ICs (ostensibly) from Tripath made a big splash on diyAudio & other similar forums in the late 2000s & into the early 2010s. They were cheap, they sounded great & they were trivial to power from a simple (usually switch mode) DC supply rather than needing a rectified +ve/-ve symmetric supply from an AC transformer.

When shopping for a suitably stout 24V power supply I came across the US made Power One CP162-A linear regulated unit on eBay, complete with original Motorola TO2 transistors, which had rewirable primary transformer windings to swap between 110V & 230V inputs. For the first few years this power supply lived in a cardboard shoebox on the floor, until I accepted that wasn't really particularly safe & crammed it into a project box with an 80mm computer fan for airflow.