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Neumann M147 (Click / Pop Noise)

Member for

7 years 5 months
Hi,
Neumann M147 was sleep for quite sometimes, today I woke it up and try to have some recording... Oh Lord, NOISE appears... like Click and Pop comes and go! Cables replaces, Inputs changed... no improvement...

What's wrong? any idea to troubleshoot other than cables?

Comments

Member for

7 years 5 months

mactreouser Wed, 03/15/2017 - 09:49
Boswell, post: 448615, member: 29034 wrote: The microphone may have got slightly damp during the period of storage. I would try leaving it powered for 24 hours in a warm, dry place, and see if that cures the trouble, or at least improves it.

Hey Boswell,
It could be, i suppose! Our place is quite moist.
It was powered on for at least 4-6 hours today before I give it a shot, Noise (clicks pops) appeared!

Btw, I stored the Mic in the dry cabinet all these while, so the problem might not the Mic itself (guess). In fact, It paired with a Tube Adaptor, and all these while it just placed on the floor (on the carpet), so i suspect, this box "damped" ? Throw it into a Zip Locked Bag and filling up some Silica Gel Bags, will do?

Any suggestions? (I'll turn the Tube Adaptor ON for a day tomorrow as you suggested)

Member for

7 years 5 months

mactreouser Tue, 03/21/2017 - 17:29
Boswell, post: 448615, member: 29034 wrote: The microphone may have got slightly damp during the period of storage. I would try leaving it powered for 24 hours in a warm, dry place, and see if that cures the trouble, or at least improves it.

Hi Boswell,
I'm here to tell that (confirmed) the Mic was caused by dampness issue as you mentioned! After 2 days of Tube Adaptor keep powered on with Silica Gel in the Storage Box for he Mic, there is No More Noise (Click & Pop)!

Many thanks for your advices with precious experience!

I'll still keep it in my Dry Cabinet, but will readjusting the temperature. It's now with Room Temperature. Will give it a shot, hopefully it works. Otherwise, will filling some Silica Gel Packs then.

Thanks once again!

Member for

7 years 5 months

mactreouser Thu, 05/04/2017 - 07:49
UPDATE:
After the successful recording, I kept it into the Dry Cabinet with the reading RH50-60, which is normal room temperature with all my other Mics.
And today, I grabbed it for coming recording section, UNFORTUNATELY, the problem appeared again! Clicks, Pops, even captured no sound! Then, I throw it into the container with filled up some Silica Gel. Hopefully, 2 days then it'll getting healthy !

So, this means, Container with Silica Gel is the BEST way to keep the M147 ? I'm wondering, why the rest of my Mics didn't bring me such Humid Issue? What do you say?

Member for

8 years 6 months

pcrecord Thu, 05/04/2017 - 10:31
mactreouser, post: 450037, member: 47968 wrote: UPDATE:
So, this means, Container with Silica Gel is the BEST way to keep the M147 ? I'm wondering, why the rest of my Mics didn't bring me such Humid Issue? What do you say?

This might meen your M147 is more sensible to humidity for some reasons. My guess is some electronic parts may have been damped or damaged by long humidity exposition and stays more fragile than normal.

Boswell will be of better help but, my un-educated guess would be to open the mic and leave it with silica for a week or more. Then reassemble it and try how long it will hold.
While it's opened, it would be time to visually inspect all parts and check if any damage coating or discoloration could help pinpoint a component that needs to be replaced.

Member for

7 years 5 months

mactreouser Thu, 05/04/2017 - 17:28
pcrecord, post: 450041, member: 46460 wrote: This might meen your M147 is more sensible to humidity for some reasons. My guess is some electronic parts may have been damped or damaged by long humidity exposition and stays more fragile than normal.

Boswell will be of better help but, my un-educated guess would be to open the mic and leave it with silica for a week or more. Then reassemble it and try how long it will hold.
While it's opened, it would be time to visually inspect all parts and check if any damage coating or discoloration could help pinpoint a component that needs to be replaced.

Oh... Appreciate to your views and it's acceptable points!
Unfortunately, my place doesn't have any Neumann Represented or Authorized service center, so this might headache!
Now, I'll try to leave it with Sealed Container with More Silica Gel, will see how's the results after all.
Besides, anything I could DIY inspect or treatment?

Thanks for advices!

Member for

7 years 5 months

John Willett Fri, 05/05/2017 - 01:50
When it's dry and seems to be working OK, do the breath test on the capsule. If it starts crackling again, then the capsule could be contaminated and needs cleaning (or replacing).

The breath test is to lightly breath on the capsule, like you do when cleaning your spectacles.

If the mic. is used as a vocal mic., especially by someone who smokes, then contamination of the diaphragm is very likely.

A good popper stopper does not only stop pops, it also minimises contaminants from the breath getting to the diaphragm.

Member for

7 years 5 months

mactreouser Fri, 05/05/2017 - 02:32
John Willett, post: 450053, member: 47971 wrote: When it's dry and seems to be working OK, do the breath test on the capsule. If it starts crackling again, then the capsule could be contaminated and needs cleaning (or replacing).

The breath test is to lightly breath on the capsule, like you do when cleaning your spectacles.

If the mic. is used as a vocal mic., especially by someone who smokes, then contamination of the diaphragm is very likely.

A good popper stopper does not only stop pops, it also minimises contaminants from the breath getting to the diaphragm.

Thanks John!
Will check that out with the Breath TEST. For now, it just like Capture No Sound, unless a little of knocking on the Mic or Loud Shout, it will only responded! Any idea?
Besides, when I leave the Mic along (without recording) the Crackling or Popping sound comes and goes.
I'm now put it into the container and covered by Silica Gel, hope this helps!

Member for

7 years 5 months

mactreouser Mon, 05/08/2017 - 18:23
After 2 days of storage in Sealed Tub with a ton of Silica Gel packs, then a day with Power Module ON, the Mic Popping Noise doesn't improve as below attachment (mp3).

This is really "scratching head" troubleshooting... Hope your helps with patience could lead me further steps to recover that issue! Appreciate in advance!

[MEDIA=audio]https://recording.org/att…
Attached files NOISE test M147.mp3 (1.5 MB) 

Member for

15 years 4 months

Boswell Tue, 05/09/2017 - 02:22
One expanation would be that you have now eliminated the effects due to moisture, and you are left with a bad contact or a dry joint (two versions of the same thing). One clue would be if the noise is provoked or changed when the microphone body (not the capsule) is tapped or knocked firmly with a rubber hammer. I keep a doctors' knee mallet for this purpose.

Member for

7 years 5 months

mactreouser Tue, 05/09/2017 - 03:20
Boswell, post: 450161, member: 29034 wrote: One expanation would be that you have now eliminated the effects due to moisture, and you are left with a bad contact or a dry joint (two versions of the same thing). One clue would be if the noise is provoked or changed when the microphone body (not the capsule) is tapped or knocked firmly with a rubber hammer. I keep a doctors' knee mallet for this purpose.

Thanks Boswell!
Here is the update and what i noticed today during the troubleshooting:

1) I suppose, the Neumann M147 Tube doesn't need the Phantom Power to Ring it (I recorded this way all these while and perfectly sweet). In fact, I purposely turned the Phantom Power (from Audio Interface) ON, boom... Sound's Right now! It just back to Normal. Sweet huh...

2) Then, the Popping Noise started Ringing after awhile soon, and now I noticed that the LED Light on the Power Supply was so weak (dim). Then suddenly, it started Flickering (Bright - Dim - Dim - Bright) and the Popping Noise keep ringing during that flickering.

3) After that, LED light was turns Bright as normal. And now, the input sound was brought up to a few more dB louder than before (when LED was Dim).

I hope you got the idea, and I'll attach the video clip soon.

4) Though now it seems back to normal (LED turns Bright, Sound keep ringing), But once in awhile there is still Popping Noise.

5) Today, I got the chance to "Breath Test", nothing weird or wrong, sound keeps ringing like a charm.

Symptoms above, Power Supply Unit (the Tube Module) issue? Or, it still MOIST/HUMID problem? And, other than the Tube Mic, will the unstable current from Power Supply Unit caused by MOIST/HUMID ?

So much appreciate to your patience and advices!

Member for

7 years 5 months

mactreouser Tue, 05/09/2017 - 04:03
Boswell, post: 450165, member: 29034 wrote: From what you have jsut said, it's sounding more like a dry joint or faulty component in the power supply unit, particularly if the popping noise is synchronous with the flickering on the power supply LED.

I see. So, what can/should I do for these test before send to repair/diagnose?

Btw, what is Dry Joint?

Member for

15 years 4 months

Boswell Tue, 05/09/2017 - 04:23
mactreouser, post: 450166, member: 47968 wrote: I see. So, what can/should I do for these test before send to repair/diagnose?
Not so easy with a mains power supply, as there is the danger of exposing yourself to high voltages if you operate it with the cover off. However, even with the cover left on, you may be able to reproduce the flickering LED and/or the microphone popping by a bit of manhandling the power supply and knocking it with your fist. You are operating at the cave-man level here, so don't overdo it.

mactreouser, post: 450166, member: 47968 wrote: Btw, what is Dry Joint?
Rather than me writing paragraphs on this, try a bit of [[url=http://[/URL]="https://www.quora.com/Wha…"]Googling[/]="https://www.quora.com/Wha…"]Googling[/].

Member for

7 years 5 months

mactreouser Tue, 05/09/2017 - 08:23
Boswell, post: 450167, member: 29034 wrote: Not so easy with a mains power supply, as there is the danger of exposing yourself to high voltages if you operate it with the cover off. However, even with the cover left on, you may be able to reproduce the flickering LED and/or the microphone popping by a bit of manhandling the power supply and knocking it with your fist. You are operating at the cave-man level here, so don't overdo it.


Rather than me writing paragraphs on this, try a bit of [[url=http://[/URL]="https://www.quora.com/Wha…"]Googling[/]="https://www.quora.com/Wha…"]Googling[/].

Thanks and now I got the idea! haha.
So, it seems like send for repair is what most encourages?!
Anyway, "hammering" on the box doesn't change anything, even I turned On & Off, Off & On again several time one after one, nothing changes.

I just leave the PSU into the Dry Cabinet with RH:60 , this helps? Since HUMID / MOIST to be concerned.
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