MXL 770 Producing A Horrible Screeching Sound

  • Thread starter Thread starter CheenoDash
  • Start date Start date
C

CheenoDash

New member
I just got my new MXL 770 up and running, with a Tascam US-200 USB Audio Interface. When I have the mic even at really now levels there is persistent screeching in the background, so recordings are unusable. Does anyone have any ideas of what this could be?

Cheers!
 
People often complaint about hums or buzzes, but screeching?
Could this be feedback? Turn your speakers off and monitor on headphones to find out.

If not, please post and audio clip of the problem. :)
 
Are you on a laptop?
There are loads of threads around here about laptop/interface noise issues but, sadly, there isn't one clear cut answer.

Sometimes people suggest that there's a ground loop.
Other times it's proven that there isn't.

Start by unplugging the laptop's DC adapter and seeing if that makes any difference.
 
Nope, it's plugged into my desktop.
I'll try it with a laptop though.
 
CheenoDash said:
Nope, it's plugged into my desktop.
Click to expand...

Oh? That's not the norm.
Do you have any other USB devices plugged in which use mains power? Printers, etc?

Unplug everything that isn't essential and try again.



CheenoDash said:
I've tried it with my speakers turned off and my soundcard unplugged.
Click to expand...

When you say you've tried with the sound card unplugged, do you mean the tascam?
If so, does that mean you're plugging your headphones into the built in audio?
If that's the case, don't do that. :)
The tascam should 100% replace on board audio.
 
No other usb devices that connect to the mains, but I unplugged my speakers and both my monitors and the sound is still there.
Before I bought the mic, it had been in storage for some time, could moister build up cause an issue like this?
 
Oh, I have both the audio interface, and an external sound card for speakers.
 
Even with the external sound card removed, with no power, the noise is still there.
 
Does this work ok with another mic? That might help narrow down your issue.......
 
I don't have another mic to test, only just got this set up. Only got it working at all today, after waiting for a cable. So I'm kinda bummed out.
 
You think power could be the issue? I don't have a hub or mixer, but I could buy a phantom power supply.
 
Yep, no screeching unless the mic is plugged in and phantom power is on. With phantom power off, I can talk into the mic for a few seconds and it will capture it, until it runs out of power I guess. While it's like that, there's no screech.
 
CheenoDash said:
Yep, no screeching unless the mic is plugged in and phantom power is on. With phantom power off, I can talk into the mic for a few seconds and it will capture it, until it runs out of power I guess. While it's like that, there's no screech.
Click to expand...

You need to check with a new mic/cable somehow.

Also, it'd be worth moving the mic around whilst listening on headphones, to see if the mic is picking up interference from something.
If the noise changes as you move, there's a likely to be an earthing problem with the mic or cable.
 
When I move it around the screeching doesn't change. I've tried it with two cables and the screeching is still there. I don't have another mic either, so this is hard. I've ordered the behringer power supply, if that doesn't work, I'll wait until I go back to uni and see if I can test it in the music tech labs.
 
Hey Cheeno ... Is this the 770 that wasn't working a few days ago and you were waiting on a new XLR cable?
 
moresound said:
Hey Cheeno ... Is this the 770 that wasn't working a few days ago and you were waiting on a new XLR cable?
Click to expand...

Yep, I got new cables and it works now... ish. Just ordered a cheap power supply, so I'll see how that goes. I don't know much about mics and such, so I'll just have to keep trying. I can send the mic back if the power supply doesn't work.
 
Then it could very well be a faulty microphone. Especially if it works for a few seconds then goes into screaming mode.
 
CheenoDash said:


In that sample, it's on quite high gain, that's only so you can hear the screech more easily. I've tried having the gain really low, but the problem is still there.
Click to expand...

On high gain, for cheapish gear, that's sounds pretty normal to me. Could you post a file of you talking, singing or playing guitar with a lower gain? Maybe a couple set at a quarter, half, etc.

I'm not hearing a bad 'screech' like the OP leads us to believe, more background noise. I have an MXL990 and on high gain it is a noisy little shit, regardless of the preamp I use. Low gain, close mic'ing, I can get some sweet recordings out of it with little to no background noise.

Do you have all your equipment running on the same power outlet?
 
You must log in or register to reply here.
Back
Top