Topic: AT4050ST REFURB - noise problems - need advice!

[dogmusic]

I recently purchased a refurbished Audio Technica AT4050ST stereo microphone.

All seemed well until I began to notice strange low level noises in my ambient field recordings (hard to notice initially because of the program material). It sounds a bit like a dying component.

I made some test recordings with the mic placed under a pillow on my living room couch. Here are some links to excerpts from those tests:

AT4050ST noise ex1
http://www.box.net/shared/ig2fhqprt1jt9412jcdt

AT4050ST noise ex2
http://www.box.net/shared/t1qst3uby1yal06d8y4y

AT4050ST noise ex3
http://www.box.net/shared/euqv605rq3yihjdz4703

AT4050ST noise ex4
http://www.box.net/shared/iavyzc553g7k0vt19onz


The record chain was AT4050ST > Sound Devices USB Pre2 > Sony M10.  There's a lot of hiss because the track levels were boosted for the excerpts. Two of the excerpts have airplanes overhead in the background.

I also made recordings using the exact same chain and conditions but with another mic, and there were no noises.

I'd appreciate any suggestions as to what might be causing these noises.

Thanks,

Phillip

[Javier Cinakowski]

That is an interesting noise.  At first it sounded like wind or cable handling noise, but then it sounded more electrical in nature upon further review.

Which stereo mode did you have the mic in?  The M/S mode has lower noise and a simpler signal path than the 90/120 degree settings.  If the noise goes away in M/S mode it will narrow it down for you.

How high did you have the gain on the SD USBpre?  If you had the gain cranked that might just be the self noise of the microphone.  If you had the gain at a moderate level than that isn't right...

This is probably a stupid question, but I am not exactly familiar with the SDpre.  Did you have phantom power engaged on both channels?  The mic requires phantom on both channels even if you are just using the mid-capsule....

I assume you didn't have the AT4050ST pad engaged? 

Does the refurb have a warranty, I would consider just sending it back to AT, they will likely send you a replacement that may have less mileage on it...

 I paid almost $1400 for my AT4050ST when it first came out, I shit when the refurbs were on ebay so cheap...

[dogmusic]

That is an interesting noise.  At first it sounded like wind or cable handling noise, but then it sounded more electrical in nature upon further review.

Which stereo mode did you have the mic in?  The M/S mode has lower noise and a simpler signal path than the 90/120 degree settings.  If the noise goes away in M/S mode it will narrow it down for you.

How high did you have the gain on the SD USBpre?  If you had the gain cranked that might just be the self noise of the microphone.  If you had the gain at a moderate level than that isn't right...

This is probably a stupid question, but I am not exactly familiar with the SDpre.  Did you have phantom power engaged on both channels?  The mic requires phantom on both channels even if you are just using the mid-capsule....

I assume you didn't have the AT4050ST pad engaged? 

Does the refurb have a warranty, I would consider just sending it back to AT, they will likely send you a replacement that may have less mileage on it...

 I paid almost $1400 for my AT4050ST when it first came out, I shit when the refurbs were on ebay so cheap...

Thanks for your reply.

Given the mic placement, for sure it was not wind or cable handling noise. I also think it is electrical.

It was in stereo mode. I'll try the M/S as you suggest.

The USBPre2 was at 12 o'clock, which is pretty much medium level, and I had phantom power engaged on both channels. Neither the pad nor the filter were engaged on the AT4050ST.

I also tried the mic through a different preamp and got the same type of noises on my recordings.

Yes, there's a one year warranty on the refurb.

I wonder if it is a component in the mic that is on its last legs and giving out a death rattle....

Thanks again for your help.

[12milluz]

It's strange indeed, but I wouldn't even worry about fixing it yourself. Contact AT- they're great on their warranties and you should get a replacement/fixed unit no problem.

[dogmusic]

It's strange indeed, but I wouldn't even worry about fixing it yourself. Contact AT- they're great on their warranties and you should get a replacement/fixed unit no problem.

Thanks, I'm probably going to do that.

Before sending it off, I wanted to make sure it wasn't something I was doing wrong that was producing that noise which might have been recognizable to someone else.

[dogmusic]

Hello, I'm bumping this because I'm hoping someone with more technical expertise than me might have an idea of what is causing this noise.

Examples nos. 2 & 3 are smaller files to download if that's the problem.

Thanks in advance.

Phillip

[SmokinJoe]

I haven't listened to your samples (I'm behind a corporate firewall).

I'll just say that I had an LSD2 which was sick (not all LSD2's, just mine).  I sent it in with sound samples and screen shots... they tested it... they said it was fine, send it back.  Repeat that a couple of times... they weren't able to reproduce the problem.  We finally realized that I was in a cold damp climate (Maine) and they were in a hot dry climate (California desert). It was susceptible to moisture.   Finally they replaced both capsules with new ones, and it was fine after that.  The moral of the story... don't give up!

[dogmusic]

I haven't listened to your samples (I'm behind a corporate firewall).

I'll just say that I had an LSD2 which was sick (not all LSD2's, just mine).  I sent it in with sound samples and screen shots... they tested it... they said it was fine, send it back.  Repeat that a couple of times... they weren't able to reproduce the problem.  We finally realized that I was in a cold damp climate (Maine) and they were in a hot dry climate (California desert). It was susceptible to moisture.   Finally they replaced both capsules with new ones, and it was fine after that.  The moral of the story... don't give up!

That's good to know. We've been having a really humid summer here. I'll suggest that as a possible cause when I send it in. Thanks!

[F.O.Bean]

Yea, it DEF sounds like its the MIC. I would send it to AT ASAP

[dogmusic]

Yea, it DEF sounds like its the MIC. I would send it to AT ASAP

Thanks, Bean, that's what I'm going to do. Looks like I may have to go through the Retailer though, so I'm just waiting for the go-ahead from him. He sent the test recordings to AT.

[F.O.Bean]

Yea, it DEF sounds like its the MIC. I would send it to AT ASAP

Thanks, Bean, that's what I'm going to do. Looks like I may have to go through the Retailer though, so I'm just waiting for the go-ahead from him. He sent the test recordings to AT.

Sweet! I hope they fix the problem, because these are some sickass mics

[dogmusic]

I received bad news through the retailer (Sonicfiber) who sold me the AT4050 ST Refurb.

He wrote: "mic came back they said there is no issue with it whatsoever."

I'm not sure how to proceed at this point.

I seem to remember that sometimes there has been a response on this forum by someone from Audio Technica. If they read this, could they perhaps listen to the recordings I made of the noises produced by this mic and let me know what they think?

I'm getting a really bad feeling about this purchase.

[newplanet7]

Go to AT directly. Explain the situation and you give them the samples.
I have heard nothing but positives about AT service.

[dogmusic]

Go to AT directly. Explain the situation and you give them the samples.
I have heard nothing but positives about AT service.

Thanks, I'll try that tomorrow.

[newplanet7]

Good luck brother. Keep us updated.