To understand the manual, one must first understand the machine. Founded by Pete Traynor in 1963, Yorkville Sound (the parent company) built a reputation on gear that could survive a fall down a flight of stairs. The Traynor 6400 is a prime example of this ethos. It is a "Mixer Amp"—a self-contained unit featuring multiple input channels, tone controls, and a power amplifier section, all housed in a single, often vinyl-covered wooden enclosure.
The power supply capacitors (two large 4700uF units) dry out. The manual’s parts list gives exact voltage ratings (often 50V or 63V). Replace them with 105°C rated caps as per the PCB layout diagram. Traynor 6400 Mixer Amp Manual
: The rear panel includes an octal-socket "stacking" connector. This allows the unit to be coupled with the Traynor 6401 , an unpowered mixer, effectively expanding your available inputs. To understand the manual, one must first understand