|
Tweakers' Asylum Tweaks for systems, rooms and Do It Yourself (DIY) help. FAQ. |
|
|
|
Tweakers' Asylum Tweaks for systems, rooms and Do It Yourself (DIY) help. FAQ. |
|
In Reply to: RFI from phono amp to pre-amp posted by SmokeTest on July 28, 2005 at 14:43:48:
Sounds to me like you have a ground loop. The Acoustech has a three-wire IEC connector and should be plugged in to a grounded outlet. Is the preamp wired with two or three prongs on the AC plug? If two prongs, can you reverse it in the outlet? If two prongs and polarized (so that it won't reverse), get a grounding adapter and file off the fat sides of the neutral blade to do the experiment. If this works, don't leave it like this because you have defeated the fuse protection. Instead, reverse the leads inside after the fuse.To find out how bad the problem is, you will need to get a portable digital voltmeter that reads AC volts. Disconnect the phono preamp and measure the AC volts between the RCA connector shells at the phono preamp output and the Golden Tube preamp input. Ideally, this reading should be zero. Whichever plug direction gives the lower reading is the better way to orient the preamp power leads.
The larger the reading is, the more leakage current the RCA cables have to carry between the units. Interconnect cables with beefy shields or ground lines would offer lower resistance to this leakage current and reduce your hum, but the better thing to do is to find the source of the leakage and eliminate it. You might have defective parts in one or both units that will create a shock hazard if they get worse.
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- hum is not RFI - Al Sekela 14:40:07 07/29/05 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
