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After completing my B3 build, I had it laid out in the case of an old EAD Ovation, hooked it up to my system, with spdif input from an Empirical audio offramp 3 and it played beautiful music.
After deciding the layout worked, I installed the components into the case via screws as supplied and now from a completely silent background, I now have a buzz/hum in both channels.
Set up is stereo, B3, with Ivy 3, Sidecar, 4 spdif with volume control. I use Genesis M60 tube mono blocs and Von Schweikert Unifield 3s.
Is this noise a ground loop whatever and how does one troubleshoot this?
It was not there before screwing everything into the chassis.
Jeff
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Were the output connectors previously unmounted, but now mounted to the case? Is the signal ground connection at the connector isolated from the case?
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The rca output connectors were previously mounted to the case. I am not sure what you mean by your second question.
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One other thing that I did differently, was wind the left and right output wires around each other whereas prior to mounting all they were not wound together.
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I misstated what I did in post 4. I wound the two wires from the left channel around each other and did the same with the right channel two wires.
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Anyone? JGlacken attached the following image(s):  DSC_0764.jpg (21kb) downloaded 25 time(s). DSC_0765.jpg (20kb) downloaded 22 time(s). DSC_0766.jpg (22kb) downloaded 23 time(s). DSC_0767.jpg (22kb) downloaded 18 time(s).You cannot view/download attachments. Try to login or register.
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Originally Posted by: JGlacken  The rca output connectors were previously mounted to the case. I am not sure what you mean by your second question. Sorry the the briefness of my questions, I was typing from my phone (which I should avoid). It sounds like you have a ground loop. Typically, the most common spot for this is output connectors that are not isolated from the chassis ground. This extra connection of grounds causes a ground loop and hum. If the connectors are isolated, it is likely a ground loop caused by wiring. For this, we need some pictures to diagnose.
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 1 user thanked Brian Donegan for this useful post.
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Pictures posted above Are they too small now? Perhaps these are better ? Edited by user Thursday, July 12, 2012 8:48:25 PM(UTC)
| Reason: Not specified JGlacken attached the following image(s): DSC_0764.jpg (57kb) downloaded 30 time(s). DSC_0765.jpg (53kb) downloaded 24 time(s). DSC_0766.jpg (61kb) downloaded 34 time(s). DSC_0767.jpg (63kb) downloaded 28 time(s).You cannot view/download attachments. Try to login or register.
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let me know if the pictures help
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Measure the resistance between these two points. If there is anything except infinite resistance, this is the problem. Brian Donegan attached the following image(s): DSC_0766 (1).jpg (98kb) downloaded 37 time(s).You cannot view/download attachments. Try to login or register.
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Then you need to isolate those jacks :)
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How does one do that? They have plastic type washers on front and back.
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I presume that you're measuring 0R (zero). De-solder all 4 wires from analogue stage stage and measure again. That way we eliminate anything else than the jacks. The washers are the way to go. You just have to make sure that they are the right way 'round to provide insulation in the chassis hole itself - centring the jack. Edited by user Saturday, July 14, 2012 6:28:32 AM(UTC)
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I have spent a couple more hours trying to isolate the output jacks. Now the hum/buzz is louder. When I push/pull on the jacks while connected, the noise gets lower and then louder. So, I believe you guys are on the right track. (no pun intended) When I measure with my multi meter, I get a reading of 1.21 nF. on both channels. (case to jack as brian suggested) I don't know what that means. I also disconnected the wires from the Ivy 3 and got the same thing.
What do you suggest next?
Jeff
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Could my problem have anything to do with the plug/switch and the mounting of same on the case?
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I suggest you measuring resistance instead of capacitance, ie. ohm not farad.
When you short your test leads from your mm, it should read 0 (ohm). When it does, you're ready to measure resistance.
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Originally Posted by: JGlacken Could my problem have anything to do with the plug/switch and the mounting of same on the case? explain. which plug/switch - mains ?
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