The 1422 changed gears midstream. It went from a tube-powered amp to a solid state amp! The specs stayed the same, but you got 'instant sound' and 'long-life circuitry.' The covering also changed from 'dark olive' to black.

Introduced:
Fall/Winter 1969 at $97.95
as the 57G1422L

Through its career, it was
Tube
57C1422L
57K1422L
Solid state
57A14221C

Retired:
In 1972 as a slant=face amp, the number was then recycled.