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Neumann M149 tube replacement
Old 22nd January 2013
  #1
Gear Head
 
🎧 10 years
Neumann M149 tube replacement

Hello guys

I have to replace the Tube in my M149 Mic. I called to get the part directly from the manufacturer, but the problem is that they sell it attached to the board and its around $450 .


These are the photos from the board. I was hopping i could just find a replacement tube and solder it in myself.


Has anyone done this in the past? I would appreciate any help i can get.
Thanks
Attached Thumbnails
Neumann M149 tube replacement-neumann1.jpg   Neumann M149 tube replacement-neumann2.jpg  
Old 22nd January 2013
  #2
Lives for gear
 
Vintageidiot's Avatar
 
2 Reviews written
🎧 10 years
Do a search, this has been discussed before. A GS member, BOWIE, sells tested tubes, pm him.
Old 23rd January 2013
  #3
Lives for gear
 
McPhaul's Avatar
 
1 Review written
🎧 15 years
We replaced the tube in ours last year so it's been a while, I think ours looked different than that. There have been at least 2 different tubes used in this mic. Ours was a 6111 and was fairly easy to remove and reinstall.

Good luck with it.

Will
Old 23rd January 2013 | Show parent
  #4
Lives for gear
 
Ephi82's Avatar
 
🎧 10 years
Quote:
Originally Posted by Vintageidiot ➑️
Do a search, this has been discussed before. A GS member, BOWIE, sells tested tubes, pm him.
Bowie is a solid guy. Knows what e is alking about
Old 23rd January 2013
  #5
Lives for gear
 
🎧 15 years
I have done this for repair customers. It is pretty easy. Buy a good NOS Phillips tube, take your time taking it apart, no caffeine before soldering. I was able to find an identical Phillips tube with the same date codes as the original one in the microphone I serviced. I think the tube was under $15 shipped, it was a 6111WA which is a military grade tube that has passed a pretty rigorous QC screening to bear the WA marking in the first place. I would not recommend unlabeled tubes unless they have been tested.

The worst thing that would happen is you would get a noisy tube and you'd have to do it again, but I have never had that happen with the WA grade tubes.

Tim
Old 24th January 2013
  #6
Gear Head
 
🎧 10 years
Thank you so very much guys. How would i know which tube is being used in this one ? Serial number maybe ?
Does anyone have Bowie's email ?
Old 24th January 2013
  #7
Lives for gear
 
McPhaul's Avatar
 
1 Review written
🎧 15 years
There is a thread here that details the new tube pretty well. You'd have to search to find it though. Our 149 is a fairly early model and the tube had 6111 printed on it. If I remember correctly the new tube does not have a number on it. If you find that old thread it should have the information.

Perhaps Bowie would know?

Again,
Good Luck
Old 25th January 2013
  #8
Lives for gear
 
BOWIE's Avatar
 
4 Reviews written
🎧 10 years
I received a message about this but I thought I'd reply here for the benefit of anyone doing a search in the future. The good news is that the 6111 tube is cheap and easy to find. However, the one problem with an oddball (rarely used) tube like the 6111 is that, in order to fully test it, a seller would have to set up a test rig and buy/make a mic or preamp to test it in. This means that you are extremely unlikely to find anyone selling fully tested, mic-grade verified 6111s outside of Neumann.

As mentioned above, you can solder in your own tube. Be sure that you verify the tube type you are removing as I've read that Neumann used a different tube when this mic was first made. Although the labeling on the tube in your pic is obscured, it looks like it could be a 6111 and from what I can tell of the labeling, you might have a 1986 Phillips/Sylvania grey-plate. I some what disagree with what was said about 'WA' designated tubes being low noise as I have tested hundreds of various WA types that didn't meet my standards for most pro-audio gear. Tubes really have to be checked out on a tube-by-tube basis because the noise floor, microphonics, and output levels always vary. Mil-spec doesn't mean nearly as much as people tend to think when it comes to tubes. Regardless, nearly every 6111 you're going to come across will be mil-spec and/or 'WA' and I haven't heard of noise issues being common with the 6111s. Going with another Phillips 6111WA (which I believe yours might be) is probably your best bet because it should give you the tone you're familiar with in that mic. Ebay is usually a sketchy place to find tubes because of the amount of rejects, b-stock, used, and fraudulently listed tubes being circulated on there. But, being that the demand for 6111s is very low, you don't have to worry as much about coming across bad pieces. If the "6111" label has been removed from your tube, it may just be a way of encouraging people to send the mic to the manufacturer for repair (other companies have done this with tubes).

If you haven't soldered on small and fragile pieces like that PCB, this is not the time to start. But, if you feel fairly confident, have at it. Just be careful with the heat. It looks like they used an adhesive to keep it from resting on the solder joints. Before you adhere a new tube with any sort of glue, let it run for around 100 hours to ensure that you don't end up with any noise or other issues (so you aren't going through the glue process all over again).

Best of luck and if you run into trouble, feel free to email me with questions. I always try to help where I can.
Old 25th January 2013 | Show parent
  #9
Lives for gear
 
Vintageidiot's Avatar
 
2 Reviews written
🎧 10 years
Quote:
Originally Posted by BOWIE ➑️
I received a message about this but I thought I'd reply here for the benefit of anyone doing a search in the future. The good news is that the 6111 tube is cheap and easy to find. However, the one problem with an oddball (rarely used) tube like the 6111 is that, in order to fully test it, a seller would have to set up a test rig and buy/make a mic or preamp to test it in. This means that you are extremely unlikely to find anyone selling fully tested, mic-grade verified 6111s outside of Neumann.

As mentioned above, you can solder in your own tube. Be sure that you verify the tube type you are removing as I've read that Neumann used a different tube when this mic was first made. Although the labeling on the tube in your pic is obscured, it looks like it could be a 6111 and from what I can tell of the labeling, you might have a 1986 Phillips/Sylvania grey-plate. I some what disagree with what was said about 'WA' designated tubes being low noise as I have tested hundreds of various WA types that didn't meet my standards for most pro-audio gear. Tubes really have to be checked out on a tube-by-tube basis because the noise floor, microphonics, and output levels always vary. Mil-spec doesn't mean nearly as much as people tend to think when it comes to tubes. Regardless, nearly every 6111 you're going to come across will be mil-spec and/or 'WA' and I haven't heard of noise issues being common with the 6111s. Going with another Phillips 6111WA (which I believe yours might be) is probably your best bet because it should give you the tone you're familiar with in that mic. Ebay is usually a sketchy place to find tubes because of the amount of rejects, b-stock, used, and fraudulently listed tubes being circulated on there. But, being that the demand for 6111s is very low, you don't have to worry as much about coming across bad pieces. If the "6111" label has been removed from your tube, it may just be a way of encouraging people to send the mic to the manufacturer for repair (other companies have done this with tubes).

If you haven't soldered on small and fragile pieces like that PCB, this is not the time to start. But, if you feel fairly confident, have at it. Just be careful with the heat. It looks like they used an adhesive to keep it from resting on the solder joints. Before you adhere a new tube with any sort of glue, let it run for around 100 hours to ensure that you don't end up with any noise or other issues (so you aren't going through the glue process all over again).

Best of luck and if you run into trouble, feel free to email me with questions. I always try to help where I can.

Did I mis-speak? Apologies if I did, it sounds like you might not sell a tested tube such as the 6111?
Old 26th January 2013
  #10
Lives for gear
 
Haz-Mat-Strat's Avatar
 
🎧 10 years
Another issue is the testing process with a tube microphone. The leads on these need a good cleaning before they are soldered in the mic. After it is soldered into the mic, it must be burnt in for at least 3 days before the tube can be tested for noise. That can lead to an extended repair time and several tubes.

Sometimes, a tube may start out with a high noise level and will settle down after the burn in.









.
Old 26th January 2013 | Show parent
  #11
Lives for gear
 
BOWIE's Avatar
 
4 Reviews written
🎧 10 years
Quote:
Originally Posted by Vintageidiot ➑️
Did I mis-speak? Apologies if I did, it sounds like you might not sell a tested tube such as the 6111?
No apologies necessary. You're right, I do have most types of tubes used in microphones and thank you for the recommendation. I may have had 6111s in the past but now I prefer to carry the types that I can test in every way. Since I don't have any gear that uses or tests 6111s, and they are easily found elsewhere, I don't really have anything to offer in that area other than basic advice.
Old 19th June 2013
  #12
Here for the gear
 
🎧 5 years
hi guys,
i recently change the neumann tube in my M149.
the new one is a raytron JAN 6111, very microphonic!!!.
the problem was, a noise,like scratching paper...i put a link to the sound...
with the new tube, no more changes...few caps changed...same noise....
if anyone had the same problem,i'll be joyfull to fix it.

https://soundcloud.com/vittoles/neumann-m149-cracking
Old 19th June 2013
  #13
Gear Maniac
 
woodsman's Avatar
 
🎧 5 years
hi. listening to your sound cloud to me it sounds like a connection issue. i had a similar intermittent sound in a microphone, even if it was on a stand and motionless. if i jiggled/tapped the mic with my hand, it would make the sound. i shined the mic pins with tiny rolled up tubes of 1000 grit sandpaper and it went away. i am guessing if you can make the noise happen, its a connection problem, or a cold solder joint. solder joints should be shiny and smooth like silver, if they look dull or grainy like the backside of tinfoil it may be a less than prefect connection. i see you changed some caps, so you might be a great solderer i hope you find an easy fix.
Old 19th June 2013
  #14
Here for the gear
 
🎧 5 years
yeap!!

thanks woodsman,
i'm working on, i've ever check all the connectors,wire,pcb connectors..but i've made a test by removing the protective head of the mic...and i tried to put it on slowly,and when i'm in contact with the body some noises comes!!! some we face off a ground problem,i'll tell you more...by the way thanks for your interest...
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