Earth/Ground Loops - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 13th November 2001, 09:26 PM   #1
diyAudio Member
 
Join Date: Nov 2001
Location: UK
Hi

Can somebody suggest a remedy to my problem. I am running a pair of 6L6 monoblocks but I have a mains frequency hum through my speakers. The only way I can resolve it is to disconnect the earth/ground from both of the power leads, but obviuosly an unsafe situation. How can I get rid of this mains hum and still maintain my earth/ground integrity.

John
  Reply With Quote
Old 13th November 2001, 11:04 PM   #2
lohk is offline lohk  Europe
diyAudio Member
 
lohk's Avatar
 
Join Date: Apr 2001
Location: Northern Noricum, near the Limes
You have a ground loop (two or more different ground connections without the same impedance), what causes the hum.
Sometimes RCA cables are the cause (the principle is inherently flawed, but sometimes only the plugs are badly soldered or dirty).

The easiest and safest way to get a clean ground is to connect ALL earth lines together in ONE point and connect THIS ONE ONLY with mains earth. (Try to find out where your ground paths - visible and hidden - actually are.) The best point for that would be at the preamp power supply (this is not only my experience).

As a rule of thumb: All cases should or can be connected to mains ground for safety reasons, but the ground of each device should be connected together in one line (never a loop) or best in form of a star. This line or better the star ground point is connected with mains earth.


There are a lot more tricks to get a hum free setup, but try the best one first.
If this does not help, you will have to specify all your devices, cables, connections, etc.

best whishes
Klaus
  Reply With Quote
Old 14th November 2001, 12:49 AM   #3
diyAudio Member
 
Join Date: Aug 2001
You might want to try wiring up a thermistor between the ground and the mains earth connection.

Keystone CL-60 ( as recomended by Nelson Pass ) or some other types of similar ratings.

  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Ground loops and containment jneutron Parts 49 18th February 2011 02:28 PM
Ground loops, speaker hum and buz steevo Solid State 15 31st October 2008 09:58 PM
UK laws - dealing with ground loops? johnm Power Supplies 9 4th August 2008 03:05 PM
Safety question concerning ground loops derMichi Chip Amps 5 9th June 2006 08:31 AM
P3A and ground loops biff584 Solid State 5 14th March 2003 02:21 PM


New To Site? Need Help?

All times are GMT. The time now is 03:10 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2