I just finished up this little budget class D amplifier project. My main goal was to use some spare parts and to see what a $15 amplifier board powered by a $20 power supply could do. I used an old Adcom Gfa-535 chassis with a pair of LJM L15Dsmd amp boards powered by a pair of $20 -/+48V Smps with some surplus capacitors. I was pleasantly surprised when I powered it up and it actually sounds pretty darn good! I do have one issue I’m trying to figure out. When I connect the amp to my SMSL SU-8s Dac which has a built in smsp and 3 prong power cord I get a sort of fluttering noise in the tweeters when I get close to the speakers. I do not get this noise at all when using a Dac(Topping Dx3pro, Nuforce HDP….etc) with an external walwart type power supply with a 2 prong non grounded power cord. Any ideas?
