JLM Audio
Well-known member
Yes the first questions here if star earthing has been done correctly is what power transformer AC volts and VA have you got running this? And also what power supply design are you using so we can work out the maths to see if it all adds up to enough
As it sounds like the unregulated volts feeding the regulator is dropping when both API & Neve are connected and the reg can then not regulate properly. If this happens the API with its diff power rails will still reject the hum to some extent but the Neve will not be able to and will hum.
As it sounds like the unregulated volts feeding the regulator is dropping when both API & Neve are connected and the reg can then not regulate properly. If this happens the API with its diff power rails will still reject the hum to some extent but the Neve will not be able to and will hum.