Before computers, back in the early (80 -83) eighties, I was an audiophile. A company called hafler marketed power amp and preamp kits. Over a period of 24 hours I built a hafler DH - 200 amp and a DH - 101 preamp. Built a system with a Yamaha PF -800 turntable, a Yamaha T-300 Am-FM tuner...