Reply To: Universal PreAmp grounding of signal circuits

[Dinx]

Thank you for your response. Setup: Larger sized Hammond steel enclosure with R-core x-fo, chokes, large caps installed on top. Power and preamp boards inside. All components from either Valvesnmore, PartsConnexion, or Digikey. Rubycons, and Solen caps, Vishay resistors. When preamp hooked up to Pre-In on R8, sound is just wonderful, with more separation and clarity…but annoying hum=buzz faintly in background. Grounding: #1: Ground pin from receptacle to chassis (1 1/2 in. away, paint scared off) #2: 2 from J1 on power boards #3: (all shielded) 1 each for pre-amp boards; 1 for 2 switched inputs; 1 for Alps volume pot; 1 from SMPS input (for tube heaters and feeding remote control board … only Chinese component, LED’s on knob (from remote control board and switch… would forget on otherwise…) 1 for 2 outputs, Of note: 6 volt difference side to side from B+, buzzing present when music paused and SMPS unplugged. 1 volt difference on pin #6 13-14 Volts. R8 is completely silent at speakers when used with other inputs, no preamp. I am considering bringing it to a tech who has a scope if I can find one… My wife of 50 years is fed up with me trying to find a fix since October. Thanks for you help. Can send pictures.