|Series||Custom 200 Series|
|Power||4x 6CZ5 (260)|
|Power||4x 6973 (260A)|
|Power Bias||fixed bias|
|Vibrato||6CG7, (1/2) 12AX7 (260)|
|Vibrato||6CG7, 12BH7 (260A)|
|Phase Inverter||2x 12AX7|
|Speaker||2x Oxford 12L5N 12"|
|Speaker||2x 5" or 2x 5x7"|
|Output||50 watts peak|
Magnatone's top of the line amplifier of the late 1950's was the true stereo output amplifier called the 280. Shortly after Magna changed ownership in early 1957, development of a new line of bigger, more powerful amplifiers got under way. Principal engineers contributing to the design included Jack Bartholomew and Don Bonham. Bonham's Stereo F.M.Vibrato design was an integral part of the circuit, and became a centerpiece to the 280's advertising and marketing.
Production for these amplifiers began in mid-1957 at the Inglewood facility. Sometime in 1959, some slight circuit changes and tube substitutions lead Magna to change the model name from the 280 to the 280A. Some further refinements to the circuit lead to the 280B model designation, perhaps in 1960 or 1961. In mid to late 1961, the 280 became the 480, was treated to a motif facelift, some circuit improvements, and the addition of reverberation.
The basic design of this stereo amp is carried on in later amplifiers though to 1966 (480, M14, and M15). The amp has two speaker pairs, each having its own dedicated output transformer and pair of push pull power tubes.
The 280 comes with two input channels each with "volume", "treble", and "bass" controls in a Baxandall tone stack arrangement. The inputs are mixed through the magnificent Stereo F.M.Vibrato.
Magnatone described the 280 as being designed for accordion, string bass, bass guitar, Spanish guitar, and steel guitar.
280s came with two jacks for remote speakers. Remote speakers were available as 1x12" open back cabinets with the same trim motif as the amplifier.
The 280 was treated to several small trim changes during its four year run. At top right and center right (actually a 260) are examples of early model trim. The "Magnatone" name plate is mounted below and behind a white header panel. Both of these say "High Fidelity", one has it below the brand name, and other splits it into two different small vertical badges. The 280 (top) is missing a "V" (unfortunately common) and the vertical "Fidelity" badge is missing as from the 260 example.
The white trim and recessed name plate were used into the run of 280A's, but at some point in 1959, the trim was changed during the 280A run to look like what is at bottom right.
If you study the location of the "V" on the 260 (middle) in relationship to the speaker hole, when compared to the similarly located emblems on the 280, the difference stands out as an easy distinction between a 260 and a 280.
See Custom 200 Series for more information on the history of the 280 and it's stablemate amplifiers.
This amp was also sold by Imperial Accordion Co. as a Tonemaster 381.