Japanese HiFi company 47 Labs released a new amplifier called the Gaincard onto the market in the late 90s, which caused quite a stir with its minimalist approach. I remember reading a review in Hi-Fi+ magazine, in which the Gaincard was very highly rated . Rumours began to circulate that at the heart of this amp was a $5 chip, now a cheap chip alone does not make a hi-end amplifier and 47 Labs has a whole philosophy regarding music reproduction, but the essence of this amp was a very simple circuit containing 9 or less parts (per channel). Somebody reverse engineered (or best-guessed) the circuit and copied it thus Gain-clone. As is usual with me i tried to build this circuit with no prior knowledge of electronics and of course once completed it didn't work. After doing some research i found two guys on a forum who were selling readymade PCBs and for a very reasonable price i bought 2x channel PCBs and matching rectifying boards from ChipAmp