Buzzing/Electrical Issues - From The House Electrics!

[spongebob]

Hoping to tap into some technical brains here!

A few weeks ago, we had some electrical work done on the house.

Moved in a month or so back, and initially, all was fine with my amps.

However, the house previously had an earth stake in the ground, this was replaced by a new distribution board, and all earthed to the current regulations.

The trouble is, since then, my amps are buzzing really loudly. Worse is when I play the single-coil pup'd vintage Ricky, it's like a wasps' nest until you touch the bridge!

We temporally removed the earth from the main fuse, and it stopped (but of course this was replaced immediately!)

What can I do here? Is there anything I can use between the socket and the amps as a noise-reducer?

Or is there a proper electrical cure?

BTW - I have written this post with technical assistance - I am not an electrician, but I do know some! Any work will be carried out by professionals only!

[Leonard Smalls]

Has the amp ever had a Portable Appliance Test?
Is the guitar lead shielded and is there continuity on all conductors? Could there be a loose lead in the guitar itself?
If there's an earth issue on only one item of equipment it's likely to be the equipment itself that's at fault.
I assume the new house earth is a PME system of some sort (i.e. earthed via the supply neutral)? If so your sparky will have given you a certificate with test results; this will hopefully show that your new earth loop impedance (i.e. the a.c. resistance from your house to the supply transformer) is less than 0.35ohms, which means that anything that's properly earthed won't be able to build up sufficient voltage between neutral and earth to give audible (or dangerous!) problems.
It could also be that there's something else on the house power circuit which is interfering with guitar/amp, such as computer switch mode power supplies, electric motors or fluorescent lights which may have been masked by the higher earth loop resistance of the old earth spike - these still comply with regs at 200ohms, and I've found them at over 1000!

[spongebob]

Thank you for the detailed response - really appreciate your help on this from an expert.

The amp has been tested - I have also tried other amps/cabs and leads, all have the same problem.

Got all the certs, quite a confusing read!

The other day, we turned everything off at the distribution board except for the hob socket, and plugged in....same problem!

When I use the Precision, it does cut out most of the noise, whereas the Ricky amplifies it.

The amps do not buzz unless you put a lead in, even without a bass, it's one big buzzing noise.

Hope this clears it up a little....!

[paul_5]

Precision PUPs are hum bucking, which might account for some of the reduction, not sure about Ricky stuff though - we're not supposed to talk about them…

[Leonard Smalls]

I'd test the leads then check the wires in the guitars...
Then check if there's a problem with the input on the amp. Easy way to do this is just use another amp!
And if the earths etc are all properly connected in the amp it may also be possible you've got dirty mains - a DC offset can cause problems with certain types of transformer. This can be removed with a dc blocker/mains filter power block though they're £50+.
Do you have any hifi equipment, and does it buzz?

[KiOgon]

First stop for me - would be the guy who did the electrical work, if you politely explain that you have a problem which is bothering you I would hope he, or the company, would be happy to come back & just check everything[b][i][u] IS[/u][/i][/b] right!

[spongebob]

Hi-fi is all fine - and I have tried 2 different amps and, multiple leads...and they're the same!

Hope I'm not causing too much of a headache on this!

[uncle psychosis]

If the noise stops when you touch the bridge/controls then the guitar is properly earthed.

Does the sound change if you move around the room/turn around? If so that's further evidence that the problem is exterior interference and not a problem with your kit.

The problem is that your body acts as a big antenna and your pickups pick up (!) the resulting noise. When you touch something that's earthed then the noise stops because you've earthed yourself and removed the noise source.

If you haven't already then shielding your guitars to try and reduce the interference may help.

It may also be worth speaking to the electricians who did the work for you to find out if there is a reason why you are now getting more interference than before. Have you had dimmer switches / strip lights installed? Those are notorious for it.

Edited July 31, 2015 by uncle psychosis

[Big_Stu]

In the good old days fridges and tube lighting were notorious for causing such problems. Try unplugging your fridge briefly & see if it changes. If it does get your sparks mate back to put a new designated clean line in for you, separate to the mains loop - (hint) it's a start on having a designated man-cave, as I believe the young uns call them.

[Qlank]

Have you tried moving the amp to another area of the house?
Plug the amp into a kitchen socket perhaps, if it still buzzes it's the main wiring, if it goes away it will be a problem with the wiring in the room you had it in before.

[HowieBass]

[quote name='Qlank' timestamp='1438423656' post='2834365']
Have you tried moving the amp to another area of the house?
Plug the amp into a kitchen socket perhaps, if it still buzzes it's the main wiring, if it goes away it will be a problem with the wiring in the room you had it in before.
[/quote]

Was about to suggest the same thing, might be an issue with the mains socket that you're plugging the amps into (assuming you always use the same one) with a poorly connected earth wire?

[spongebob]

Yes, sorry to say we tried that - different amps, different rooms and sockets, even isolated one single plug point (everything else off) and it still did it!

I did find a possible solution to my problem -

http://www.amazon.co.uk/Behringer-MICROHD-Hum-Destroyer-HD400/dp/B000KUD2G4/ref=sr_1_1?ie=UTF8&qid=1438433339&sr=8-1&keywords=behringer+hd400

Anyone ever tried one of these? It looks like just the possible job....?

[Number6]

Have you tried any ferrite rings / filters on the power cord? Do a search on the Maplin site. The new earth is probably causing more noise because its picking up electrical (emc) interference.

Ferrites are cheap and worth trying first. You may have to wrap the power lead around a large ferrite ring a few times.

You can also buy clip on ferrites to maybe try on your bass lead.

Hope this helps

Edited August 1, 2015 by Number6

[ambient]

I used to have a similar problem at a venue I played at regularly, it was caused by power lines running directly overhead !

I think I'd check with the guys who did the work, and maybe get a 2nd opinion too, just in case.

[Slipperydick]

Disconnect your router and cordless phones from the mains, switch off lights, especially ones with dimmers. disconnect anything thats on standby as well. See if it makes a difference, then disconnect anything with a display, such as heating timer, fridge etc. And I mean anywhere in the house, even if it runs on batteries.
When you find it, you can suppress it at source - always the best way. Dont forget it could be something in your neighbours house.

By the way, is it a hum or a buzz ? and is it 50HZ or a higher pitch ?

Edited August 1, 2015 by Slipperydick

[HowieBass]

Nice little demo of ground loop hum and how to kill it (with one of those hum destroyers)

http://youtu.be/jSA2F1AwboU

[Norris]

I'd speak to the electrician that did the work. He may be able to suggest possible cause and solution.

[spongebob]

Nobody seems to know, he'd said he's never seen it before!

I think it could as said above - improved earth getting interference....although not from anything within this house, as we tried a socket totally isolated.

I may well try the Behringer box - thanks for video link - might just solve it?

[Slipperydick]

[quote name='spongebob' timestamp='1438443022' post='2834572']


- improved earth getting interference....
[/quote]

Errm - No !

[HowieBass]

I'm no electrical expert but going back over what you've described I'm wondering if the old earth connection was a better ground than the one you now have with the new distribution board - I presume the new system is electrically safe and hence certificated but ground is no longer at 'zero' volts? The earth stake was a better conductor than whatever is now used for the earth contact point?

[TimR]

Earthed back at the substation and picking up interference from your neighbours.

[Slipperydick]

[quote name='TimR' timestamp='1438458758' post='2834706']
Earthed back at the substation and picking up interference from your neighbours.
[/quote]

'Interference' would be more of a harsh buzz than a hum.

[Skol303]

[quote name='spongebob' timestamp='1438433543' post='2834498']
I did find a possible solution to my problem -

http://www.amazon.co.uk/Behringer-MICROHD-Hum-Destroyer-HD400/dp/B000KUD2G4/ref=sr_1_1?ie=UTF8&qid=1438433339&sr=8-1&keywords=behringer+hd400

Anyone ever tried one of these? It looks like just the possible job....?
[/quote]

Those Behringer boxes are quite good. I commonly get ground loops at home in my DAW/recording set up. Tried the Behringer MICROHD and it worked ok - killed around 90% of the noise.

I then upgraded to an 'Ebtech Hum Eliminator' on the recommendation of a mate. Google it for info. they're quite expensive brand new - around £100 - but commonly crop up on eBay (I got mine for less than £30). Works a treat and kills 99% of the hum!

[Slipperydick]

[quote name='Leonard Smalls' timestamp='1438363271' post='2834007']
Has the amp ever had a Portable Appliance Test?
Is the guitar lead shielded and is there continuity on all conductors? Could there be a loose lead in the guitar itself?
If there's an earth issue on only one item of equipment it's likely to be the equipment itself that's at fault.
I assume the new house earth is a PME system of some sort (i.e. earthed via the supply neutral)? If so your sparky will have given you a certificate with test results; this will hopefully show that your new earth loop impedance (i.e. the a.c. resistance from your house to the supply transformer) is less than 0.35ohms, which means that anything that's properly earthed won't be able to build up sufficient voltage between neutral and earth to give audible (or dangerous!) problems.
It could also be that there's something else on the house power circuit which is interfering with guitar/amp, such as computer switch mode power supplies, electric motors or fluorescent lights which may have been masked by the higher earth loop resistance of the old earth spike - these still comply with regs at 200ohms, and I've found them at over 1000!
[/quote]

Is there anything in current regs to say you cant keep the earth rod or fit a new one in the same place, and have PME es well ? Might be a good compromise and wouldnt cost the earth.

Much better to find the source and eliminate/ supress it it that to try and supress the amp though isnt it ?

Edited August 1, 2015 by Slipperydick

[TimR]

[quote name='Slipperydick' timestamp='1438465328' post='2834760']


'Interference' would be more of a harsh buzz than a hum.
[/quote]

If it goes away when he disconnects his earth and there's nothing on in his house then the 'hum' must be being induced through the earth via a source outside his house.