HIFI RETRO on Instagram: "Late 1970s. Hi-fi is no longer only about schematics and measurements. It becomes visible. Readable. Spectacular. Pioneer understands this early and imposes a visual signature that will leave a lasting mark: blue. “Blue Line” was never an official Pioneer designation. It is a term coined by enthusiasts to describe several Pioneer series sharing a strong visual and technological identity. First come the compact models with blue bargraph displays: SA-510, SA-610, SA-710,