My friend gave me an AT4040, but unfortunatly, it produces a somewhat loud hum/buzz. It sounds like a grounding problem. It still picks up sound fine, but it has the buzzing in the background. I opened it up to see if there was any loose wires but I didn't see any. Any ideas on how to fix this?
AT4040 mic buzzing
- Thread starter tbuck92
- Start date
Shadow_7
New member
Are you sure it's the mic?
My STO-2's pick up buzz when in proximity of high(er) voltages. i.e. IF A/C + Washer + Dryer + stuff on, then outside of riding the mic < 3' off the ground, buzz... Even 20-ish yards from the house. Not that that's your problem, but one source of buzz.
You might try angling the mic at different angles and see if the buzz goes away or changes. Upside down? Sideways? Towards the ceiling? Towards the floor? Guitar strings and other things have been known to be influenced by fluorescent lighting and other oddities. Lights on/off? Otherwise ground is a usual suspect.
You might also try shielding the mic and see if that has an influence. Old computer towers and other metal-ish things can be used in proximity (1'-ish) to try and identify the general direction of an influence. Although probably better off checking the circuitry. Are the solder points frosty or shiny? Does anything wiggle, that probably shouldn't.
My STO-2's pick up buzz when in proximity of high(er) voltages. i.e. IF A/C + Washer + Dryer + stuff on, then outside of riding the mic < 3' off the ground, buzz... Even 20-ish yards from the house. Not that that's your problem, but one source of buzz.
You might try angling the mic at different angles and see if the buzz goes away or changes. Upside down? Sideways? Towards the ceiling? Towards the floor? Guitar strings and other things have been known to be influenced by fluorescent lighting and other oddities. Lights on/off? Otherwise ground is a usual suspect.
You might also try shielding the mic and see if that has an influence. Old computer towers and other metal-ish things can be used in proximity (1'-ish) to try and identify the general direction of an influence. Although probably better off checking the circuitry. Are the solder points frosty or shiny? Does anything wiggle, that probably shouldn't.
Now I'm getting an even weirder sound, I believe it's interference? Like you said maybe it's from the computer or some appliance? None of my other mics have ever done this which is why i'm so confused. I recorded a sample of what it was doing and attached it if that helps any.
I have two of these mics. One has had a hum problem and the other has always worked perfectly.
On the one with the hum problem, it sounds very much like the hum sound in your mp3 around 5 or 6 sec. Like you I've opened the mic and found no loose wires but what tends to fix the problem (which seems to return over time) is tightening the set screw in the base which keeps the 3 prong connector secure.
I don't know if the set screw has anything to do with the mic ground but it definitely corrects the problem on mine. Unfortunately I have to re-tighten it every few weeks. I don't know why this is not the case on my other AT4040.
I've never had the problem with the higher pitch noise heard in the last half or you file so your mic may have a different problem or you may the same problem plus a second problem.
On the one with the hum problem, it sounds very much like the hum sound in your mp3 around 5 or 6 sec. Like you I've opened the mic and found no loose wires but what tends to fix the problem (which seems to return over time) is tightening the set screw in the base which keeps the 3 prong connector secure.
I don't know if the set screw has anything to do with the mic ground but it definitely corrects the problem on mine. Unfortunately I have to re-tighten it every few weeks. I don't know why this is not the case on my other AT4040.
I've never had the problem with the higher pitch noise heard in the last half or you file so your mic may have a different problem or you may the same problem plus a second problem.
Shadow_7
New member
+1 mic cable.
A bit too random to be the mic, unless you were moving it while making that sample. Or there's some moisture involved. Or something is really broke. If you're using an interface, you might check it's cable (USB/ Firewire). That sort of scratchy drift sound is normally something with the PC. Make sure that none of your cables drape across your display. Or otherwise get any closer to the computer than they need to be. And that you're not running every application in the book at the same time that you're trying to record. i.e. those 32+ taskbar icons by the clock.
Otherwise bad mic. The spec sheets do have a 110F- and low humidity warning for AT mics. As in do not exceed. Which is quite easy to exceed where I live. Just leaving them in the car for a day, even in a shaded trunk could easily exceed.
A bit too random to be the mic, unless you were moving it while making that sample. Or there's some moisture involved. Or something is really broke. If you're using an interface, you might check it's cable (USB/ Firewire). That sort of scratchy drift sound is normally something with the PC. Make sure that none of your cables drape across your display. Or otherwise get any closer to the computer than they need to be. And that you're not running every application in the book at the same time that you're trying to record. i.e. those 32+ taskbar icons by the clock.
Otherwise bad mic. The spec sheets do have a 110F- and low humidity warning for AT mics. As in do not exceed. Which is quite easy to exceed where I live. Just leaving them in the car for a day, even in a shaded trunk could easily exceed.
I had a Shure ksm 27 that did the same thing and if I moved the chassis just right (as if I was tightening it) the noise stopped but came back with the slightest movement of the microphone.
I sent it back to Shure and they fixed it and stated that it was a grounding issue.
I sent it back to Shure and they fixed it and stated that it was a grounding issue.
