joessportster Posted April 21, 2014 Share Posted April 21, 2014 (edited) I actually admire the OP's persistence. That's what it takes to fix a problem like this. I went through a similar thing last fall that spanned about 2 weeks. I finally Killed all of the hum/noise from my system. (I had to, because I went to 114 db Horns). And the addition of 2 more Amps for Bi-amping. I dismantled my entire system, as well as all the electrical work behind the system. I routed one simple dedicated A/C line into a sub-panel. And then hooked all of my gear into 1 outlet via a much quieter Power Strip than I had before. I eliminated 100s of feet of interconnect by removing components that I never use any more (Tuners).... removed RCA interconnects to the TV in favor of Optical into the DAC. My system is as quiet as a mouse now, until those big Oris Horns Explode with a Full Orchestra. I never add anything to my system now, without a thorough evaluation of what noise I'm introducing. Don't give up. In the end it is worth it. You will succeed eventually" +1 Edited April 21, 2014 by joessportster Quote Link to comment Share on other sites More sharing options...
Chris Hornbeck Posted April 21, 2014 Share Posted April 21, 2014 (edited) With the shorting plugs in, the buzz from the horns is almost inaudible. You must have your ear right up to the horn and listen carefully. (Without the shorting plugs the hum is louder and can be heard from 5-10' away). Touching the ground of one channel of the preamp to one channel of the amp does not increase the hum (but it is still there with your ear to the horns and listening carefully). When you touch BOTH grounds on the preamp to BOTH grounds on the amp, the buzz returns to the same level as without the shorting plugs. Excellent! and pretty interesting too. The fact that you can induce the noise with only grounds connected confirms that we're seeing a ground loop. An interesting test at this point would be to disconnect the preamp completely and to connect the two amplifier grounds to each other (only). Amplifier shorting plugs in place, nothing else connected except speakers, both amps plugged into same power strip. Noises with inputs open don't mean anything at all - they're a confounder that just distracts us. Do you have an outlet tester? One of those little plug-in guys with three lights? They're not infallable (they can be fooled by reversed neutral and safety grounds) but they're a quick check of more dangerous issues. Also, do you have a voltmeter of some sort? We're heading there. Happy Ishtar, Chris Edited April 21, 2014 by Chris Hornbeck Quote Link to comment Share on other sites More sharing options...
eth2 Posted April 21, 2014 Author Share Posted April 21, 2014 Chris, I am out of town this week. I will follow up when I return Thanks Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.