Trouble Report : One Quick Question . . . Mic Repair

Music industry veteran and Recording Studio Technician Ken McKim, of Trouble Report, tests the sound health of three Neumann microphones, two of which need capsule repairs.
HAVE QUESTIONS about, or need repairs for, your recording studio? FOR A TIMELY RESPONSE, contact Ken at [e-mail].
Trouble Report is a New York City-based full-service technical support company for the recording industry in North America.
Trouble Report is a New York City-based full-service technical support company for the recording industry in North America.
Have questions about, or need repairs for, your recording studio? Contact Ken at [e-mail].

[@lucianoluggren]

Hello. I have a U47 clone with an M7 type capsule and yesterday while recording some vocals there was a humidifier in the place because the singer believed that it helps her. To be polite, I didn't make it turn off, but after a few hours an intermittent noise appeared in the microphone, I quickly put it in a bag and left it on to generate heat and turned off the humidifier. After half an hour perhaps the noise disappeared. Today doing this test I checked that everything was fine, I hope I haven't generated permanent damage. Thanks for the video test, greetings from Argentina.

[@troublerep]

Hi Luciano, If you did the breath test, what was the result? ++Ken

[@lucianoluggren]

​@@troublerep Just normal, no noise today after the breath test. Maybe what I identified yesterday as a humidity noise in the capsule was something else and just coincided with the humidifier in the room. I'll see how the microphone performs in the next uses. Your test helped me check if that was the problem, thank you.

[@troublerep]

@@lucianoluggren Here's hoping. Let me know if anything changes. ++Ken

[@recordingbox44]

this was very useful. I've been recording some podcasts with a Neumann TLM 103 and have been getting some slight lisps at times. Almost like a poorly set de esser. Searching the internet to see what it might be.

[@danalexanderaudio8506]

Ken , you are a widely respected and well known tech and I have great respect for your abilities....I suggest that one needs to inspect the diaphragms , beyond just the humidity test. All moisture sensitive capsules do not need reskinning . Often, simply cleaning the capsule will eliminate this issue. Basically, a dirty diaphragm will conduct electricity when moist...that makes the ocean roar... Cleaning diaphragms is quite simple. You can find my noninvasive method on my youtube video channel. Remember this: never touch the diaphragm with anything: no cue tips, no photo brushes; nothing....

[@mikg2618]

Very helpful info, that mean I can’t fix any AT4033 mic that work nice with low pass filter and sound noisy without LPF. Also that means any noises collection means bad internal pop filter and will lead to bad capsule and $ to repair it? I’ve fixed once Samson C02 ungrounded mesh problem and removed noise appearance (excessive capacity) with body part approaches. While disassembling mesh pop filter fall apart and was replaced. Sensitivity increased.

[@producerm.d.a9806]

This was very helpful

[@MrAlmaor]

I have a mxl 2000 microphone and it recently got both of what you said at 3:09 !

[@nicosuj]

Have a u87i picked from ewaste from a really big radio from where I live. The capsule was punctured and the circuit had the FET dead, and and other minor stuff. I though on reskining the capsule, but I am really broke and had to get 2 u47 chineese knockoff and merged together. Got a new FET and rebiased it. Now it works like a charm, despite having other character (but still rich sounding), is still undercontrol and trustworthy. Not only that, I learned a lot getting my hands on this engineering masterpiece. I learned to clean the capsule (NOT EASY PEOPLE, really worth the money you spend when you give it to someone with experience, the gold layer is really thin and removes quite easly with the wrong pressure and cleaner, and the capsule can deform too, and a lot of considerations, specilaly for multipattern mics), I learned that the components that has aren't advanced, but really precise, the filter and attenuation can infere really bad if the capsule has issues, and quality tantalum caps are always worth. Those mics are an act of incredible balance.

[@troublerep]

Suggestion: Go to dan Alexander's site. He has a video on his method for cleaning the diaphragm on a condenser mic. Somewhat counterintuitive and very intelligent.

[@mojogearfx]

Hi, great video!How much will cost to reskin a Neumann U87 capsule?Thanks!

[@musictutorjaygogoi]

For long life of condenser mic.... A pop filter sud be used always and silica bags sud be kept when mic is packed,, it sud not be packed quick after recording vocals, let moisture dry itself n hour or half then we sud pack it with silica bags in pack. I lost a costly mic due to my negligence. I m poor to afford new one now

[@rahuldhande90]

You are not alone brother but i hope you kept up with the hustle. Peace.

[@JosephCraciun]

Very good advice

[@wisdomabel7974]

Please I got a problem with my behringer b2 pro, the issue there is when recording it doesn't record complete vocals it skips in vocals and u can see this produce from the wav vocals

[@nxstress]

I have an Aston Origin and when I turn on phantom power the microphone works for a split second but then I can't hear my voice at all. BUT I can hear a very low amount of audio when I rub the microphone with my fingers. I checked the interface and the cable and they both work. I don't know what is wrong with this microphone other than the capsule is bad now. is there a way to fix the capsule or is it done for?

[@underpressureman]

do you know what the symptoms of a capsule with fine scratches would be? Basically , (I hate myself right now)I think I may have slightly damaged my capsule a little bit while cleaning it! I believe the brush I used was abit to coarse. Its clean overall know but the gold looks spotty and dull in places and slightly scratched! I mean I'm just wondering what the technical reprecutions are? I don't know why I rushed it. Ive cleaned another capsule before with good results, but this time I knew my brush needed replacing and I didn't have the proper solution.

[@FoxyCanDoIt]

Ken McKim i have the same problem but Mine make's a Beeping sound but i dont want to spend to much money on it what do i do

[@shrawalrp]

Hi there i m a sound designer from Nepal. I have a rode nt4 stereo condenser microphone with i use a lot. But lately one of the mic doesn't seems to be working with the phantom power of my recorder. I tried it with different recorders but the result is the same. But it works when i use a battery. Could you help me please.

[@Satchmoeddie]

How much does re-skinning cost? I have some old Neumann mics from when AVR went under. Only about 35% of them work well. Do you replace ribbons on ribbon mics. I just did that today on an old mic. It did not go well at first, but it is back working and off my bench. Then a cheapie crystal mic for harmonica came in. The Kobitone $4 element is no longer being made. I make audio amps for every purpose, except Muzak. Gotta draw a line there. I also fix and build tube comps, expanders, etc. Luv IT!

[@purpleheart69420]

bro I got an AT2035 I feel like the mic picks up too much sibilance do you think there might a problem with it? (Yes I use a pop filter, in fact 2)

[@davidviera3347]

Hi, I'm David from Cuba I'm so sad because a friend gives me a Bluebird SL new! After a week of use...and very little use suddenly stop to work...can you tell me any suggestion??? Please, I need help and in Cuba is impossible to go to any music store or techs because here there is not music stores!!! Greetings!

[@user-js7ox8ec1n]

hi i have a dragon fly blue microphone how can i get skin replace? how much would cost?

[@franciscojoseleandromarcel7043]

Hi Tomxico here from Portugal. My studio condenser mic works just fine but sometimes then the signal is very low or even vanish away. Is there a bad condenser or something ? It's not about fantom Power cos I have oneother condenser mic and works just fine. Can someone help me ? Please I am locked a home due to the virus. Peace and health to you all. ThanK you

[@parryscosmos]

M147 use a tube that commonly goes noisy... you can get a new one but tricky to install... I got a new valve from Watford Valves (UK). and installed it my self. Its a tricky install if your not a good solderer....

[@pauloswear]

how can i reescand the capsule?

[@Satchmoeddie]

Diagnose why. Many things can cause this. Bad tube, or JFET, who knows? Worst case bad capsule. Tomorrow is my birthday. I happened upon a surplus store that usually NEVER has any good audio tubes, but today, Telefunken EL156 power tubes new in original boxes! Then it got better, Telefunken VF14s NIB! Then I found RCA 6550s, NIB, and GZ34s UK made NIB. I had to shell out some dough, but I am stoked! The JFET used on the 84 is not bad. The famed $60K+ Dumble guitar amp has a JFET input.

[@Hassan_Omer]

My rode nt1 mic isn't working. It was just sitting on a mic stand. Then today I just tried to turn it on and there is no input signal. I have checked the cables, phantom power and it didn't work, I also tried my other condenser and dynamic mics on the same device , inputs and cables and they all work fine. The humidity levels in my room are not good. They reach upto 87 in the winters. After watching your video it seems to me that humidity is the problem. So is it possible that I can somehow fix the mic without replacing the capsule ? Thank you.

[@troublerep]

Hi Hassan, While the video might lead you believe that a bad capsule would be the number one suspect in a mic problem, the truth is that the possibilities are almost endless. Try taking the mic to a dryer environment if possible. Give it a day and try it again. If it comes to life, try the breath test. If it remains dead or responds badly to the test, get in touch with me at [e-mail] and we'll discuss options.

[@alexanderhill308]

Hi there! I just picked up a Microtech Gefell UM 70 and it has the same issue as the U87 in your video. Would it be worth it to have the capsule reskinned or should I just return the mic? Is there someone that you would recommend sending it to to have it reskinned? Any help would be greatly appreciated! Your video was very helpful!

[@pkl-n5g]

i have a EO-200 condenser microphone and when i plug it in my computer it sounds fine but there's one problem it does like silent popping crackling sounds can you please help?

[@pkl-n5g]

@Teena Seehusen shut up

[@pkl-n5g]

@Felix Hornyak shut up

[@bluearcherx]

I have a concdenser mic (a cheaper Electro-Voice PL37) but when it is plugged in it makes a constant rumbling sound. Sometimes louder than others, but it is basically constant.. any thoughts what this might be?

[@thesleepstate]

Same.. I wish someone had answered in the intervening 7 years :) Did you find out the cause and fix it ?

[@YourAverageGamerShow]

What would you do if the microphone was simply dead??

[@Mitch-Cumstein]

great asmr video bro keep it up

[@DVSnark]

I’ve got a groovetube gt55 (u87 clone) that works for a while and then starts to fade out and back in just like the last one here (not as long). Little bit of popping noise sometimes when turning on. Sounds like it needs a new capsule, thanks for the video! By the way is this something that is caused by singing too loud into the mic or is it the capsule going bad?

[@troublerep]

Hi Jacob, There are three routes to explore. 1) Get a mic tech to clean the capsule (if you haven't had this done, and if you're not inclined to do it yourself). This sometimes clears the debris on the capsule face that might be causing the "charge" to collapse. Easy, quick, and inexpensive. 2) Replace the capsule. For about $150 to $300 you can buy a new capsule that will surely outperform the one that came with the mic. You can go to a site like Microphone-Parts.com and look for either an RK87 capsule (one that more or less directly replaces the one in your mic), or for a little bit more, buy an RK-47: not quite as bright as the RK87, smoother. If you have any soldering skills (and a little courage), you can do the swap yourself. 3) This last fix is the one I mentioned in the video, and it is usually the first approach, but the GT55 is a relatively inexpensive mic, and the capsule is not a premium brand. A reskin costs about $400, and depending on who you have do the work, it can take up to four months. I'd say, do this only if you love the sound of the mic, and you don't want the sound to change in any way. And by the way, sing as loud as you are inspired to. It's not what caused this problem. Good luck.

[@MiguelAriasS]

Hello, sir. I have a similar problem with a Behringer B2, i comes and goes without the need to breathe on it. Is it the capsule too?

[@troublerep]

This is a humidity issue. Breath is an intense source of moisture - hence the "breath test". But ambient moisture, if there is enough might also produce similar results. However, as Dan Alexander has pointed out (a few comments down), another possible fix might be to have the capsule cleaned. And there are other electronic reasons the mic might behave as you have described. Before you have the capsule reskinned, it would be a good idea to have a tech evaluate the mic. It might also save you some money, as well.

[@sadpotato7029]

good day sir, i have a quick question since i also have this problem. the thing is the microphone got exposed to extreme heat coz im dumb, then the mic started having a low frequency rumbling/popping noise. not all the time, but sometimes. my question is that, is it the capsule that got damaged or the capacitor itself?

[@troublerep]

I replied to this post two weeks ago and for some reason the reply didn't stick. So, more detail about the amount of heat it encountered would be helpful. BTW, the capsule IS the capacitor. It's made of a kind of plastic, so yes, high heat might damage it. In any case, you will have to have a technician examine it to really know. If you need to add to this conversation, you can reach me at [e-mail].

[@beebee4383]

My bm 800 condenser fell and stopped working can i do anything to fix this?

[@satur.3351]

mine got we bcz i thought that my popfilter was already dry but it was wet

[@pedrosolocutorbc]

Hi Mr Ken Mckim. I got a U87 Ai. It sounds very good, the capsule is original , not cleaned. But I've been heard a 60 hertz background humming noise. It is very low, that I need to push at full level to heard it in my Yamaha HS8. But it is there, because I've plugged in the same cable and input another mic and that noise disappear. When I put a hand on it and touch it, this noise stops. Let me tell you that I've had already opened it and tested some wires inside searching for some bad contact, and nothing is there. Do you have some suggestion to me? What look for inside that can make it sounds with this 60 hz noise? If you send me an e-mail I can send you some videos, audios or pictures. I'll be very grateful if you can help me. Any help , any suggestion will be so value! Thanks!

[@troublerep]

The most likely source of 60Hz is poor grounding within the mic body. Possibly the capsule head not making good enough contact with the rest of the mic. Also, check to see that the place where the electronic ground meets the chassis ground. If you have a voltmeter with a resistance or continuity mode, you can actually check the ground by placing one lead on pin 1 of the XLR connector and the other lead on any other metal part (somewhere that has not been anodized) The reading should be very low - like, 0.01 ohms, or lower. Then, it's a matter of re-establishing the ground connection. Please continue this conversation on [e-mail], if you need to. ++Ken

[@monowelt]

Hi Ken, thank you for your interesting video. You seems the only one on youtube, who is covering this topic. I watched you, as i have issues with my DIY U87i from MicAndMod.com. I made it and soldered it, but no idea how i can repair it. Maybe you have an idea. I dropped it recently and after that it became very noisey. I thought the capsule is broken, but after unsolder the capsule its the same pink noise. I don't know the connection between capsule and electronics....Maybe the capsule keeps everything in balance and i need a new capsule to stop the noise?

[@monowelt]

Thank you for your help. I tried that all but it doesn’t change the noise level of -60db. Doesn’t matter if the capsule is soldered or not the noise level is the same. It’s there a interconnection between circuit and capsule. I mean is it important that a capsule is in the circuit to sound noiseless or is there maybe a other part of the circuit broken? Cheers Mat

[@kenmckim3626]

@@monowelt You're getting into tricky area here. The capsule connections need to be terminated in some way, or it introduces noise of it own. If you observe no change, then it's probably something in the electronics and not the capsule. I think you mentioned this is a DIY unit. That means you built it (?), and that means you have some soldering skills. I would go back through the circuit board and touch up all the solder points, using very small amounts of solder, but making sure that the solder connection is solid - that means that the solder flows and really bonds with the component leads. If that doesn't get it, you should seek technical help.

[@monowelt]

Yeah I soldered it and put all parts together. Thanks for the tip. I’m gonna try to solder every point carefully again. If not it might be the capsule. Stupid me, why did I dropped it. Thanks again Ken. Cheers Mat

[@kenmckim3626]

One note: if you disconnected the capsule and got the same noise, the exact same noise, then it would seem not to be the capsule. Good luck. Let me know how it turns out.

[@KREYSCENDO]

Hi there! I just bought an AT2020 paired with a Scarlett 2i2. it started becoming horribly loud when i used it, please help :(

[@troublerep]

There's not enough detail about the problem here to form al meaningful reply. "Horribly loud" in that the gain went up excessively?, the noise floor increased to unusable levels? If so, what kind of noise? Have you tried it with other mix pres to confirm the symptoms? You can also reach me at [e-mail].

[@KREYSCENDO]

@@troublerep Hi thanks for replying! Turns out I just had to finish setting the audio interface up, its all good now :D

[@troublerep]

@@KREYSCENDO I love it when it's easy.

[@wisdomabel7974]

This was under helpful..

[@robynmiles31]

Hello, I have an Avantone CV-12. I’ve had it about a year and a half. It simply stopped working. The power supply comes on but I’m not getting any sound from the mic. When I plug it into my interface I only get noise but no sound.

[@troublerep]

Hi Robyn, There are half a dozen (at least) possibilities. Bad tube, bad cable, bad power supply... I know you said the pilot light comes on, but that doesn't guarantee that all the voltages it's supposed to generate are getting to the mic. None of these things - other than the tube, maybe - are easy to trouble shoot in the field. I'd be happy to have a look at it if you don't have access to technical help where you are. Which brings us to: where are you? It would be easiest if you respond to this reply at [e-mail]. Thanks. ++Ken

[@robynmiles31]

@@troublerep ok I will email. Thank you

[@Omar-ts3yd]

The same thing happened to my mic .but I live in Nigeria and I have no idea what to do about it

[@robynmiles31]

@@Omar-ts3yd sorry to hear that. I sent mine back to the dealer, I had a warranty

[@hiteshsaini7184]

bro I have presonus audiobox itwo studio bundle, but my mic is giving some electric noise sound to me and when i close my hand to mic then that noise stopped, can you tell me what can be the problem.

[@troublerep]

Hi Hitesh, Is the electrical sound a "hum"? If it is, turn the mic 90 degrees (then, take your hand away). Does the hum change? Louder, quieter?

[@ohjayesimpson67]

I'm not an expert, but i've taken apart a few microphones. To me it sounds like their may be a grounding issue. If you're able to, take it apart and make sure the middle pin on the xlr connector is connected properly to the circuit board. With my AT2020 (xlr) mic, I found that the screws themselves grounded the circuit board to the housing, so you might want to check them as well. Sometimes they just need to be tightened a little more.

[@MarlyMarlz]

I have a warm audio wa87 it clips randomly once the Phantom power is engaged the mic never dropped only warm weather because I live in the Caribbean any advice

[@davidpoole5675]

I have a similar problem with my tlm102! Did you find any solution?

[@MarlyMarlz]

@@davidpoole5675 no I have to send it bk for repairs

[@yzeemusic7963]

@@MarlyMarlz you got back??

[@MarlyMarlz]

@@yzeemusic7963 yes very fast best customer service ever!!

[@yzeemusic7963]

@@MarlyMarlz cool bro

[@bobsoulfull1]

I have an akg perception 200 and it has great quality but as I'm sing into the mic it seems that the signal goes in and out. This is even after I mess with the levels and gain what does this mean?

[@semiografo]

What happened to your AKG? I have a perception 170 with this issue.

[@RayKit]

Everytime he says "capsule" drink..

[@Oportunidades369]

??

[@YAEVIN]

I have a WA-47 Tube and while recording, I can hear fluttering and the sound of an overloaded signal. Could this be a humidity issue? The problem has persisted for a few months now.

[@troublerep]

Hi Yaevin, Are you using the mic to record vocals when this happens? Are you using a pop filter?

[@ViLeFreT]

@@troublerep I'm having the same exact issue with a different microphone. Even with a pop filter, the slightest bit of air causes a fluttering sound. For example, if I wave my hand past the microphone, it distorts. I have tested other mics on this setup and had no issues.