The No.1 Website for Pro Audio
Weird White Noise Interference?!
Old 4 weeks ago
  #1
Gear Maniac
 

Weird White Noise Interference?!

I've just had the weirdest (electronic?) interference that I've never experienced before and was hoping someone could shed some light. I'm out of town tracking vocals in a converted walk in closet with my U47 and I've found in this space there is a NOTICEABLE increase and decrease in white noise/hiss depending on my proximity to the mic. If I move my hands towards or away from the mic it changes. Depending on where I'm standing it changes. It's not directional by rotating the mic, but it does become manageable if I find a sweet spot in the room. But Ive never had this type of white noise shift before on anything. Can anyone explain this??
Old 4 weeks ago
  #2
Lives for gear
 
brianroth's Avatar
 

Perhaps some sort of RF interference that ends up sounding like white noise. What mic preamp?

Bri
Old 4 weeks ago
  #3
Gear Maniac
 

I’m pretty confident it’s not the pre, which is a 1073 located in a different room. The noise in question is seemingly random dependent upon where the mic is located in the booth and where any physical presence is in relation to it. While I would normally expect certain types of buzzes or RF, it is straight up hiss and a type of behavior that would normally be indicative of a faulty, noisy tube, but definitely is not based on the conditions that produce the problem.
Old 4 weeks ago
  #4
Lives for gear
Don't discount the preamp. RF could be picked up with your body in different positions and blocked by others... but carried down the line, and not turn audible until it reacts with something in the pre or ADC.

(Diagnostic step: put a small cap across the mic line. There are already a couple of 100 pF caps in U47's output circuit, but they could have failed... or not be enough in this particular environment.)
Old 4 weeks ago
  #5
Gear Maniac
 

I made a quick video to show what I'm talking about, anyone got any other suggestions after seeing/hearing it?

Jay Rose, unfortunately I don't have my tools where I am out of town to try that, so mostly just trying to figure out what is causing it.

Old 4 weeks ago
  #6
Lives for gear
 
Radardoug's Avatar
 

Probably rf. Look for cell sites or transmitters in your area.
Old 4 weeks ago
  #7
Gear Maniac
 

This is on a large farm — I can’t definitively rule out that type of cell interference, but given the locale, I’m highly skeptical.
Old 3 weeks ago
  #8
Lives for gear
 
Radardoug's Avatar
 

There are cell sites in the country you know, and they are usually higher powered. Also on a farm, it could be processing equipment, such as in a milking shed. Motor controllers and the like.
Old 3 weeks ago
  #9
Lives for gear
 
crosscutred's Avatar
Does it happen in other rooms?
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump