Turtlerock Forum

Hey all,

This post has been a long time coming but something has happened over the weekend just gone which has made this old problem become inherently worse and fueled my anger once again, I'll outline the story:

About 2.5 years ago we noticed that between business hours an electrical 'fizzing' coming thru our speakers, instrument cabs, light fittings, ac psus (say in the back of our mac pro psu, gtr heads, ups's, phonic power conditioners/power strips) and also at the mains box out the front of the factory. It had never been there before but rather just one day, arrived. This noise was SO intermittent it was ridiculously hard to pin point when it was going on but was sometime between 8am & 5pm Monday to Friday. It never got into our recordings unless a high gained/distorted guitar amp or microphone that needed an AC psu (tube mics) was needed, + we could always change our recording times around the sound, mixing was fine too as it was only on playback thru our unbalanced speakers & not the active orientated ones nor outboard equipment.
About 8 months ago I decided to give United Energy a call (our local supplier of the lines in the Dandenong area) to ask simply, WTF. Described the problem & they said that it wasn't their problem & no one in the area had ever complained so must be our equipment making the noise and that we'd need to get in contact with the ACMA to get someone out to check out the issue. Very helpful.

So called ACMA and a really nice guy Larry came out to check out our issue. He brought all of his equipment and started to do some tests when the noise was active. We thought it might be the mechanics across the carpark when their drills or grinders are in use, but sadly no. We even took some ac power via extension leads from the mechanics and another fence welding business over to our studio & plugged in the key equipment which the noise was coming thru. Same thing - ringing in PSUs, unbalanced speakers etc etc. We thanked the other businesses for their time, gave them some beer & had to call it a day as the noise stopped. Larry said that it must be some kind of dirty AC leakage coming from somewhere within the immediate area, how to pinpoint where it is will simply have to be a kind conversation with each business... Not an easy feat to go about by any means. He said that there are AC filters that you can put over your mains/switch board but they're not cheap and a pain in the ass to organise if the electricians don't fully understand the issue at hand.

A couple of months later we were set to track metal guitars on a saturday knowing fully well the noise wouldn't be there, but alas it was. Paul (studio partner in crime) & I were so f**king fed up by this that he stayed in the studio on the phone with me whilst I drove up and down the carpark + street to see who's there and where it's coming from. I noticed that whenever he said it stopped, a carpentrys business extractor fans would shut off and then when they kicked on again, the noise would come back. AH HA, finally - might've found the cause. I pulled over outlined the issue with the gent from the business who pretty much told me in a very nice way 'to go f*ck myself' & that 'he has a business to run, doesn't affect me so I don't care'. Again, very helpful guy!!!

SO, now knowing where it's coming from and from what I could see, the saw dust extractor was running on a 3 phase line (56 or 64 amp by the looks of it) makes me think that they've got some dodgy wiring leaking back down the line and hitting our substation which feeds 12 factories + their subboxs about 40 meters away.

Is that a crazy idea or can this happen? Over the weekend just gone it's gotten much worse for some weird reason, the sound is amplified, it's coming thru all our balanced gear and is heard when I demo recorded a track in protools from one of our external mic pres.

I recorded the sound on my h4n Zoom almost the day it started that long ago just to document but as I've explained it's never really affected our business operation until the last few months... I'll upload the sound somewhere and copy the link over.

I'd love to get your ideas on how to approach this, what the cause of this is & mainly, HOW THE BLOODY HELL DO WE FIX IT!!! I don't care about the cost (within reason), just want it to piss off.

I've gotten some trusted electrician's numbers from some good gents off Turtlerock here which I will try but thought I'd run it all by the brains trust too.

Thanks in advance everyone.

gee that sounds pretty unfortunate.

- is there 3 phase to your premises? if so have you tried a different phase?
- is there a MDF/Electrical Supply room? do you know how everything is wired up in there?
- what's your grounding like?

it may be a case of the right technician rearranging the MDF wiring so you get a cleanfeed of power from the street and separating the grounds of the premises.

the other thing i would look at is disconnecting everything and reconnecting everything bit by bit. sometime there is no rhyme or reason to electrical problems, and it could be one dodgy thing you have creating or amplifying the noise on the line.

good luck!

Thanks for the reply Chirs.

There is a main frame at the front of the building which connects our mains yes. Also I forgot to mention Zoran the property owner put solar panels on the roof to run his power off (office & lights) which is apparently not connected to our sub box. I do need to chat with him more about this just to really grasp how the whole place is wired.

3 phase - Hmmm that's a very good question... If there is i might throw a distro in and see if the power comes thru that. Let me check!

Grounding isn't amazing but I am in the process of putting our own star ground in out the front via a 5 foot stake. Just waiting the thicker awg cable to arrive. Our console & patchbays will all be connected to this technical ground when done. Atm it's all floating.

Thanks

BTW heres the noise in a dropbox link:

https://www.dropbox.com/s/eqa96yp8q45ng ... 8.wav?dl=0

told me in a very nice way 'to go f*ck myself'

I see... so he told you to go forth and be fruitful.


Anyhow the first is to check is the ground connections and check if there is potential drop between ground and neutral. The electricity supply tech should've done that.

Second thing to do is get that big earth rod in and water it every day! Every studio should have a well maintained ground rod.

Third thing to do is put a scope across the supply and see if you can see any dirt on the waveform when it's happening. If the extractor fans are running 3 phase, then changing the phase of your supply may not help.

the saw dust extractor was running on a 3 phase line (56 or 64 amp by the looks of it)

That's like around 14000 watts! I'm glad I haven't got his power bill.

Fourth thing, if all else fails, put the problem back in the hands of your supplier and let them know you've found the source of the problem. Ask them to check the grounding and wiring of the carpentry factory. Your supplier has a responsibility to you as a customer to provide a clean supply. If they're not helpful, find a another supplier who's willing to provide you with a solution to your problem.

Lastly... You could always offer to buy the carpenter a new set of brushes for the motors running his extractor fans! When brushes start to wear out they cause more arcing between the brushes and the commutator. I wouldn't be surprised if that and a combination of bad grounding in their factory could be the source of your problem.

Good luck Dave... not that luck will have anything to do with it.

Hope this helps.