introduced in 1952, the rugged military grade 5670w is a special quality industrial vintage vacuum tube developed from the 2c51
oe certified for airborne up to 80k feet, premium best-of, popular for a variety of applications including mixers + amp builders
the incredibly low microphonics w/ thick mica vibration damping, and revered solid-disc getter, all contribute to the sonic lore
the sound stage is smooth, warm, relaxed, well suited for many genres, excellent mids, w/ plenty of detail, and punchy tight bass
an ideal upgrade replacing russian + chinese, considered along with tungsol bendix and western electric as audio crown jewels
these oe boxed military issue were specially screened, workhorse long-life, and balanced section match, important for audio use
+ often military devices were in stand-by, w/ periodic testing, and often replaced no matter the duration, yielding a nos burn-in