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hums & buzzes

Hey all, just got my project studio up and running but am having minor grounding issues. I have everything run into a power conditioner then that to the wall. I am getting a small 60 cycle hum through my monitors. its not loud but audiblle when the room is silent. Also my guitar is getting a buzz only when i fret notes, this is a new phenomina since assembling this new space. The guitar is run via a boss br-8 8 track recorder (crappy for recording, great for guitar sounds). i've yet to check the power at the wall to see if its grounded, but wondering if theres other things that will create hum.

thx

Mark

Comments

Halifaxsoundguy Mon, 04/16/2007 - 20:33
from the monitors back:

everything is plugged into an ART power conditioner.

monitor ->XLR -> alto s-12 mixer -> gold plated RCA's with Tip /Sleeve adaptors -> MBox 2 Pro -> intel mac.

I think I addded the mixer to combat the hum. I've tried connecting the monitors directly to the mbox, but the little hum is still there.

For fun I plugged from my cdr machine directly to the monitor and it was still there.

I'm going to try unplugging everything then working up.

Thx

Mark

Halifaxsoundguy Mon, 04/16/2007 - 22:45
I tore everthing apart, then reassembled bit by bit. I think the problem source is my power from the wall, i'm going to have to get a wall plug tester to see if its grounded.

As far as gain staging. If that refers to everything being at unity gain, then I had everything but the monitors at unity. The monitors were at full. After putting the monitors on half volume, the hum is still slightly audible. Very much toned down.

As far as the guitar buzz, it exists when the unit alone is plugged in. I think i'm SOL until I find out whats happening in the wall plug.

Thx

Mark

Kapt.Krunch Tue, 04/17/2007 - 03:26
While you're checking your AC receptacles, you may even want to check to see if they are wired properly. You may want to go ahead and use a tester anyway, to see if it's grounded properly. A lot of places may have the hot and neutral bass-ackwards, and it's possible that it could cause problems. Might as well spend an hour or so checking ALL your outlets. When I moved into this place, I had ungrounded outlets, some grounded outlets, and some wired backward. It was a mess. You'll ESPECIALLY want to check, at LEAST, all the others in the room with your equipment, in case you plug a guitar amp or something into another another.

So, in case you aren't familiar, (or someone else is curious):

TURN OFF the circuit breaker for the outlets you will be testing.

Remove the cover plate. The neutral wire should be white, and it should be connected securely to the (probably) silver screws on the left side of the receptacle, which also has the wider plug hole.

The black wire is hot, and should go to the brass screws, or the right side with the smaller width plug hole.

The ground wire should be obvious.

Just to clarify this a bit more, here's a link to look at:
http://www.hometips.com/content/receptacle_intro.html

I assume you know about all the other noise-inducing stuff, and have considered them. Dimmers, flourescents, neons, running power wires in parallel with signal wires, living directly under high-voltage power lines, the powerful electro-magnetic flux generator your creepy neighbor runs constantly to block out the government's electronic eavesdropping, etc.

Kapt.Krunch :?

Halifaxsoundguy Tue, 04/17/2007 - 22:38
On the topic of electricity. My neighbours are in their 50's, and when old bill gets into the liquor well; he starts cranking up the tunes (top 40 from '72). But why not go the extra mile and crank it when i'm going to bed on wednesday night at say 11:00. Well ol' Bill did. I just coped with it. Ol' bill did the same thing the following night, so I thought I'd give him a warning (As I have a monster stereo, but chose to not to piss the world off with it.). Being the creative individual that I am, I knew if I wanted to get ol' Bills attention, I needed to do it with style. So I went online to find the perfect track to play for Bill and the old hag. I cranked the stereo to about 80% to the tune of electricity arcing about ten seconds worth. Good times, I eventually went to bed. Before long ol' Bill was back to his old ways of cranking his 'Best of '73' records. So I said fuck it, and gave him the Entire Limp Bizkit chocolate starfish album at about 80%. It was Gold. I haven't cranked up the volume since, nor has he.

Mark

Halifaxsoundguy Fri, 04/27/2007 - 14:51
Ah HA!!! I have found the source of all my problems. Continuing the wonderful storiess of my fantastic neighbours, there is more to add. When I first got this apartment I would have to write down the numbers on the water meter because it was in my room and give it too my neighbours. I kept forgetting each month so I called the water people and got them to install a wireless reciever for reading the meter from the street. Theres now a wire from the reader in my closet to the wireless device on the other side of the house. I found while i was playing guitar, the closer my pickups got to the wire the louder the buzz got and just to double check it i did the same with my room light. Alll the buzz is in the wire.

All that I saiid I think i'm still a little clueless on how I would ground that.

hueseph Sun, 04/15/2007 - 21:39
Regarding the 60cycle hum. Are you sure that's what you're hearing? Just seems unusual to me that it would be so mild. When I think of 60cycle hum it irritates me beyond end.

As far as the buzz that you hear when you fret a note, that sounds more like 60cycle hum to me. What I think is going on is that the noise is always there but there is a gate that kicks in when you stop playing.

I'm no pro so take it with a grain of salt.

Kapt.Krunch Mon, 04/16/2007 - 03:17
Yep, they're right.

What I might do is to just start with the simplest I/O scenario you can get...like a mixer with NOTHING plugged in but headphones, and listen. Then add amp/speakers and listen. Then start adding components back in one at a time until you hear the noise. If you have stuff in a rack, or even metal cases stacked on each other, I'd probably unplug everything from the power...just to keep a weird ground path from the cases possibly grounded together from happening. You may find that isolating a unit's case from the others may solve it. Who knows?

Sooner or later, you'll find what's causing it, and then you can deal with that. You may even find it's just a bad cable, or something.

Kapt.Krunch

Link555 Mon, 04/16/2007 - 06:13
Can you explain your exact studio connections?

Here is some useful background info:
http://www.epanorama.net/documents/groundloop/home_solving.html


Here is a line isolation transformer (best solution):
http://www.hammondmfg.com/171.htm
This will isolate your PC from the other circuits.

or this -which may not be as good but much cheaper: HUMplug-e
http://www.21best.com/21_best/electronic/security/video/filters/for_sale_.html

Best of luck.

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