Shorter than the articles, sharper than the tables: how each system is read, and where it fails.
Serial plates, tube charts, transformer bells, speaker magnets, pot cans, chassis stamps.
Open the guide ↗MethodWhy an amp cannot be older than its newest original component — and what that means for a conflict.
Open the guide ↗Code systemTwo printed letters on a sticker inside the cabinet give a Fender amp's year and month — and the same alphabet came back on the reissues from 1990, which is why
Read ↗Code systemAlmost every vintage amp contains at least one part stamped with its manufacturer, year and week. That code is the fallback when the maker's own numbering does
Read ↗Code systemFrom 1990 Fender pasted a dated quality-control sticker on the rear of the chassis. It is the company's own dating mark for the years after the tube chart was d
Read ↗Code systemTwo stickers carried Marshall's build date after the letter system ended: the barcode label from October 1992 and the date bar from August 1997.
Read ↗Code systemBefore the QA sticker there was the ink stamp: four digits pressed inside the chassis, read one way from the mid-1960s and the opposite way after 1979.
Read ↗Code systemA born-on date is the date the maker wrote on the amp itself. Mesa/Boogie is the best-known case, and it is the only truly authoritative date those amplifiers c
Read ↗Code systemCircuit codes such as AA763 and AB763 identify a schematic revision. They bracket an era of production, and they are constantly mistaken for build dates.
Read ↗Code systemLoudspeakers carry the most consistently readable date code in a vintage amp: maker, year and week, usually on the rim of the basket at the back.
Read ↗Code systemPots are the easiest codes to find and the weakest evidence in the amp. They are date-coded ahead of use, and a single pot is never enough to date anything.
Read ↗Code systemSome makers publish serial ranges that give a year, some number their amps without any chronology, and several have no amp serial system at all. The plate tells
Read ↗