Mains Buzz.. I think!?

[Chris.]

Ok so what is the skinny on this one?

 

Everything seems to produce noise in my room. Things that i can see might be the problem

 

1. I have about 6 4-way adapters in the room so everything is ultimately powered from the same wall socket.

 

2. My new Comresser Sustainer seems to multiply the noise hugely.

 

3. Computer monitors is another obvious one, so when i'm recording i turn them off. Cuts it a wee bit

 

4. Leads. so many leads.

 

I was watching Jules Holland last night, and the live music is SO well produced, everyone sounds perfect and i was thinking how on earth do they do that with all those mics and amps etc, and there's me running two amps with two mics and the S/N ratio is damn near 1 in my room.

 

I'm moving into my new flat in feb so want to set everything up in the best way possible as far as noise reduction is concerned, so want to clue myself up about it before i go in the flat with the tape measure.

 

Pray tell to what extent you all suffer from noise, i'm interested to get a general view on all levels, not just the pro's.

[fantasticsound]

Most noise can be categorized in one of two ways. Noisy components and noisy electrical.

 

You can't do much about the first without A. getting rid of said component or B. Having a tech go through and replace the parts that are noisy.

 

The second, can be a result of many factors. Common ground is good (all your electrical on the same ground) but often you'll end up with some voltage on what ought to be earth ground. In the U.S., the OSHA ground (0ur third prong on most new electrical plugs) is often wired to cold water pipes, assuming they will exit into the earth and ground everything. But for one reason or another (and especially in large buildings, such as apartments and businesses) improperly grounded equipment can actually create significant voltage between the positive or negative conductors and ground. That will almost always create noise in audio systems, even if you have the most pristine components.

 

And don't forget about non-audio components other than computer monitors. Fluorescent lights have ballasts that are notorius for inducing buzz into audio systems. Good fixtures, even fluorescent should be quiet, however. And dimmers are terrible for creating noise. In many instances, they create audible noise even when there is no audio system in the room!

 

If you can get a real ground rod and attach your ground to it, this should decrease the chance that dirty power will create noise in your system. But that is difficult to get in an upstairs apartment.

[Chris.]

Right.. i'll have a good scout around for both types of noise. take out the components types and fault-find for electrical ones.

 

dimmers, and flourescents are things i didn't consider before, i think there are a good few energy saving bulbs in my current house.

 

i was thinking about getting dimmers in my new flat, but you say i should avoud all that? good one!

 

i don't know about the ground situation since in the UK all plugs have a ground naturally. i've often wondered how you guys across the pond ground your stuff with only the two prongs.

 

[The Geoff]

Chris, if you've an electrician mate, you should get him to check that the earthing is competent in your new flat. I moved into a house a few years back where the end of the earth wasn't actually attached to anything.

[Chris.]

HAHA,

 

hey geoff, if i asked an electrician mate, he'd definately laugh at me .. i have a degree in Electronic and Electrical engineering, and i'm asking an Electrician .

 

he'd have every right to laugh.

 

LOL.

 

I'll check it out about the earth in the flat, cheers. Although the quantity surveyor came to me with a clean bill of health!

[The Geoff]

If I'd only known!!!

 

[Chris.]

Originally posted by Geoff Byrne:

If I'd only known!!!

 

Degrees are a joke really, you don't learn a thing till you work in the field

 

Happy 100th geoff!!!!!!!!

[The Geoff]

Ooooooooooooooohhhh! I didn't actually notice - thanks!!!!!!!!

[Chris.]

How far does away does a transformer have to be (plug point) for it to be considered negligable.

 

i'm going to be doing lots of tests today.

[Ricochet]

Originally posted by Chris_C:

i don't know about the ground situation since in the UK all plugs have a ground naturally. i've often wondered how you guys across the pond ground your stuff with only the two prongs.

 

Not much stuff is sold over here anymore without a third conductor to ground. We haven't had houses built with grounded metal water pipes for a long time. (They're usually PVC.) The ground's normally run to a long (about 6 feet) metal rod driven into the earth outside. Not as good a ground as the old pipes were, with their larger contact area to the earth. If the ground around the ground rod dries up, you have a very poor ground. It can help to find it and moisten the earth there, if you think that might be a problem. The connection can get corroded and high in resistance, too. The neutral conductor coming in from the transformer on the pole will be grounded by a rod driven into the ground at the pole. Differences in earth potential between the two ground rods can cause "ground loops" making noise. Not much you can do about that, though. Tying the neutral wire and ground wire together at the service entrance would fix it, but I don't know if that's allowed under the electrical codes.

 

Best to talk to a professional electrician if you have any concerns about the adequacy of your house wiring's ground.

[Big Red 67]

Good test of componants is to mute or turn down every thing. Turn up one by one. Even the effects. You will know where the noise is when you turn up/unmute the offender. I found this when looking for a noise in my studio. I have an SPX 90 that is a hummer. I found that if I run out to it as loud as possible then I can run the device at a lower level producing less noise.

[jetboy]

first of all a compressor/sustainer is going to amplify and noise already in the system.

 

The basic nature of a comprseeor is to even out both the loud and soft passages so that they are closer to the same level and a sustainer is going to amplify a softer signal so that it reduces the decay of a note.

 

Both of these things tend to bring up the noise floor, maybe using a noise gate before the compressor would help reduce the noise floor before the compressor increases it.