Dating fender amplifier serial
The guide for that is much simpler: be nice, ask questions, offer beer.
Look for original black levant covering, a gray grille and the old block-style Marshall logo.
Starting in July 1969, Marshall starting using official serial codes.
They were initially broken down into three parts: the model code, the serial production number and the date code.
The same model codes from the previous section of this article still apply, although the model code "RI" is also seen for reissues. Starting in October 1992, Marshall moved away from stamped metal plate serials and began using stickers with a xx-xxxxx-xx format serial and a bar code. The sticker-based nine digit scheme lasted through July 1997.
These serials are much easier to understand, as they don't include any model or date codes.