I agree with Greg that loops are troublesome; I would like a bit more info from Bob actually. [Drawings, photos, (off-list if you like) ]. What power [watts] is expected of the supply? What amount of capacitive smoothing/filtering is on the high voltage? This LED - it is across the HV?
Star earth/ground is definitely required inside any audio gear. The power supply currents shouldn't flow in any of the signal wires. "Essentially they get very unhappy if one plugs in an rca line level input while the amp is turned on" - Did you mean there is audio signal on the RCA cable? Does the problem occur when the RCA outer only is connected? ie connecting an earth/ground to the RCA outer perhaps? I am not sure what you mean by 'noisy', but noise shouldn't be seen on the LED - it is 'too fast' to show; especially as I think you mean the LED flickers ie very low/high volts for an appreciable time?. I am very interested in whether your audio source is floating [and for that matter, if your amplifier is floating]. John K. ----- Original Message ----- From: gregebert To: neonixie-l Sent: Wednesday, September 16, 2015 12:04 AM Subject: Re: [neonixie-l] smps protection question My first suspicion is a ground loop, and they can be difficult to locate and fix. I'm assuming the audio and HV are on separate PC boards, so the solution is with cabling and perhaps a filter in the right location. It's possible an oscilloscope can help, but be aware that the ground-lead to your scope can add to the noise you see; there are several good techniques posted on the web. When I built my first computer, the ground loops were SO bad that I could hear interference on an AM radio several houses away. It was amazing how easily I could trace the wiring inside the walls, because of the noise. After I removed the power-supply ground loops, there was no detectable noise outside the computer cabinet. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/ce7437fe-a1d6-4a1f-8a70-e73626ead8e5%40googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/18B5E1A2EEB64A888C895C2F9BE7E8A8%40compunet4f9da9. For more options, visit https://groups.google.com/d/optout.
