L-5, ну хватит уже воздух сотрясать.Там чёнрным по белому написано что в 75 выпустили д.х. а потом дочерняя фрирма Босс запихала этот эффект в педальку.Если чеестно то устаю общаться с умными дворниками а так ничего личного.
... и добавил: с точностью до наоборот 
About a year after Roland introduced the chorus effect in the legendary "Jazz Chorus" amplifier in 1975, the daughter company BOSS already delivered this effect in the form of a pedal. This classic is especially popular in the jazz and Pop-scene because it adds a richer sound, which can make a big difference especially for clean sounds.
... и добавил:L-5, по твоей ссылке.
1975JC-series
These guitar amps were equipped with stereo chorus effects, and are still used by guitarists around the world
1976SYSTEM-700
Modular synthesizer system
Japan’s first large-scale modular synthesizer system; it was purchased by organizations such as NHK and BBC
CE-1
Chorus ensemble
The first BOSS-branded effect processor