The Blues Junior is a tube guitar amplifier introduced in 1990 by the Fender Musical Instrument Corporation.It is aimed at achieving the warm, tube-driven tone common in many styles of American blues and blues rock dating back to the 1950s, while remaining both portable and affordable.
The Fender Blues Junior is most similar to the Fender Blues Deluxe, which adds a "drive" channel, an effects loop, and uses 6L6GC output tubes for 40 watts of rated output.
Like many Fender amplifiers (particularly in the Hot Rod series), many limited edition versions of the Blues Junior have been manufactured since its introduction in 1995.
A set of three matched Groove Tubes 12AX7 preamp tubes and two matched Groove Tubes EL84 power tubes, graded according to Fender's specifications, are used in all factory Blues Juniors.
The Blues Junior uses a nonadjustable power tube bias (no way to vary the bias point), but it is fairly "hot" and can accommodate most matched pairs on the market.
The standard Blues Junior is dressed like a traditional black Fender amplifier, with black Tolex upholstery and a silver cloth speaker grille.
Although they differ in their external visual aesthetic, all variants of the Blues Junior for a given year are produced with the same electronics, apart from the speaker/driver.
Limited editions may use varying driver models, such as the Jensen C12N found in the NOS Lacquered Tweed Blues Junior or the Jensen P12R found in the Relic edition.
Fender does not always include these limited edition versions in their updated catalogs (or on their website) either because too few were produced (only a few hundred in some cases) or perhaps because of exclusive retailer agreements.
The codes are usually handwritten, and the letters can occasionally be hard to decipher. There is no reliable way to date 2003-2005 amps other than to ask Fender customer support to look up the date from the serial number, although you may find a date code on the speaker.