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R/E/P => Klaus Heyne's Mic Lab => Topic started by: SDVIG on February 24, 2015, 04:51:59 PM

Title: Neumann U67- capsule original or not?
Post by: SDVIG on February 24, 2015, 04:51:59 PM
Hi, this is my first post.
Here below are some pictures of the capsule.
I think it's not the original capsule.
(It looks very good and does not have numeric marks.)
And the wiring is not like the Neumann.
In mode 8, this does not work.)
Since I do not have a second U 67, I cannot evaluate it sounds good or bad.
Here, with 37 seconds sounds the microphone.
http://www.youtube.com/watch?v=xdaCbw16EgE
Vocal chain: Neve 1073LB-LA2A-Avid HD I/O.
Thanks for the answers.

Excuse Me.
I have to learn English.
Title: Re: Neumann U67- capsule original or not?
Post by: klaus on February 24, 2015, 06:57:56 PM
Hello Sergei,
It's not a Neumann capsule, and, if past experience with copy capsules serves me well, this capsule will not sound anything like a Neumann K67.

Considering that you have a very early U67, judging from the head assembly, I would recommend to buy an original Neumann capsule for this mic- either used or new, to restore its sound to its original glory.

Best of luck,
KH
Title: Re: Neumann U67- capsule original or not?
Post by: SDVIG on February 25, 2015, 04:17:50 PM
Thank you Klaus.

Considering that you have a very early U67, judging from the head assembly......

Is that good or bad?
I called  to Sennheiser today.
In the near future they will inform me the price of the capsule.
Maybe I'll look it at eBay.
I think I can replace the capsule myself,
because I cannot find a specialist in Moscow.
I will solder two wires as far as possible from the capsule.
Or there are any subtleties?
Сan it be installed on either side?
Thanks again.
Title: Re: Neumann U67- capsule original or not?
Post by: klaus on February 25, 2015, 07:19:20 PM
Thank you Klaus.
Is that good or bad?
It's always good to have one of the few rather than one of the many, all else being equal.

Quote
Maybe I'll look it at eBay.
Just make sure that it is a genuine Neumann product you are buying, and not one with aftermarket diaphragms ("reskinned" = no no!) otherwise you end up where you already are.

Quote
I think I can replace the capsule myself,
because I cannot find a specialist in Moscow.
I will solder two wires as far as possible from the capsule.
Or there are any subtleties?
If you are skilled and comfortable repairing small items, and have a calm hand, and a calm mind, I see no problems. The capsule comes with the diaphragm wires already attached. But keep the solder iron's heat away from the diaphragms, and avoid splashing solder flux onto the skins!


Quote
Сan it be installed on either side?
Yes, it can. Use the side on the front that sounds better to your ears.

Good luck!
KH
Title: Re: Neumann U67- capsule original or not?
Post by: SDVIG on February 26, 2015, 01:41:33 AM
klaus
Thank you so much for your help.
Title: Re: Neumann U67- capsule original or not?
Post by: soapfoot on February 26, 2015, 09:23:04 AM
I've replaced/installed a few capsules, and one thing I've done for extra insurance is to place a very small plastic bag over the capsule itself when soldering the leads. This is just extra insurance against any errant solder flux splash (though I've never had that problem, it never hurts to err on the side of caution).
Title: Re: Neumann U67- capsule original or not?
Post by: SDVIG on February 26, 2015, 04:25:42 PM
soapfoot
Thank you.
Title: Re: Neumann U67- capsule original or not?
Post by: Uwe on February 26, 2015, 05:07:46 PM
Sergey, for servicing your Neumann microphone or obtain parts in Russia please contact:

Sennheiser Audio Ltd.
Semenovskaya 1A, 30th Floor
107023 Moscow
Russia
Tel.: +7 (495) 620 49 63
Fax.: +7 (495) 620 49 64
E-mail: [email protected]
www.sennheiser.ru
Title: Re: Neumann U67- capsule original or not?
Post by: SDVIG on December 25, 2015, 05:17:51 PM
Hello.
I replaced the microphone capsule.
I took a capsule of the new working U87AI.
In U87AI capsule works just fine.
But U67 has a low level with a new capsule.
I checked both sides of the capsule.
What is the problem?
The microphone has a 200 ohms.
The power supply NU67 does not have a PAD.
I have done everything that is written here:
http://www.neumann.com/forums/view.php?bn=neumann_archive&key=979411126&v=f

Thanks for the answers.
Title: Re: Neumann U67- capsule original or not?
Post by: klaus on December 25, 2015, 05:36:48 PM
You will need to start checking some basics:

1. Is the mic an all-original U67, or, suspecting from did someone do monkey business in the mic amp as was done to the capsule? (please post front and rear views of the mic amp, and please use a decent camera or close-up format when doing so the latest pix are blurry).

2. Assuming the mic is all-original, you need to make some voltage measurements inside the mic: B+ = 210VDC, Heater = 6.3 VDC. If you do not know how to measure, please let someone with high-voltage condenser microphone experience do it for you.

Once you have transmitted the answers to the two points above, maybe we can get a clue.

Best of luck, and Merry Christmas!
KH
Title: Re: Neumann U67- capsule original or not?
Post by: SDVIG on December 25, 2015, 06:17:24 PM
klaus
Thank you so much and Merry Christmas!
More photos:
Title: Re: Neumann U67- capsule original or not?
Post by: SDVIG on December 26, 2015, 10:36:04 AM
klaus
Hello.
Thanks for the answers.
(New photos are in the previous post also.)
More photos:
Title: Re: Neumann U67- capsule original or not?
Post by: klaus on December 26, 2015, 11:41:02 PM
Your pictures do not show anything suspicious. Everything looks clean and original, aside of a fine version of an old stock Amperex/Phillips/Mullard EF86 tube.

Next: voltage measurements!
Title: Re: Neumann U67- capsule original or not?
Post by: duskb on January 07, 2016, 04:26:19 PM
Hello.
I replaced the microphone capsule.
I took a capsule of the new working U87AI.

Not to be a Monday morning quarterback but that mic will really improve if you are able to obtain a K67 capsule. I don't know if Neumann manufactures them anymore or not but worst case find a damaged original and have Theirsch reskin it. (I had Doug Walker in Canada redo one of mine and it compares very well against an unmolested original capsule).

I've never heard a K87 on a 67 but I cant imagine the mic sounds 'right' with it on.
Title: Re: Neumann U67- capsule original or not?
Post by: soapfoot on January 07, 2016, 05:23:45 PM
Dusk,

I'm afraid I must disagree with your advice to go with a re-skinned capsule as a cost saving measure. Re-skinned Neumann capsules represent, to me, a very poor value in comparison to a good Neumann (original) capsule, even if the fully-original Neumann capsule is more expensive. I have never heard a re-skin that sounded "right" or even especially close to it, even by the "best" re-skinners.

To my knowledge (Klaus can confirm), the K870 and K67 are identical, so there's no reason to act rashly.

If it IS a true K87 we're talking about, the difference between the K870/K67 is that the backplates on the K87 are electrically insulated from one another. I'm not sure the difference that would make in a U67, but I bet Klaus knows.
Title: Re: Neumann U67- capsule original or not?
Post by: klaus on January 07, 2016, 07:19:11 PM
To my knowledge (Klaus can confirm), the K870 and K67 are identical.

Correct.

Quote
If it IS a true K87 we're talking about, the difference between the K870/K67 is that the backplates on the K87 are electrically insulated from one another. I'm not sure the difference that would make in a U67, but I bet Klaus knows.

You can use a K87 in a U67 as long as you connect a wire between the two (insulated) backplates, to make it one.
Title: Re: Neumann U67- capsule original or not?
Post by: duskb on January 08, 2016, 01:07:53 PM
Dusk,

I'm afraid I must disagree with your advice to go with a re-skinned capsule as a cost saving measure. Re-skinned Neumann capsules represent, to me, a very poor value in comparison to a good Neumann (original) capsule, even if the fully-original Neumann capsule is more expensive. I have never heard a re-skin that sounded "right" or even especially close to it, even by the "best" re-skinners.

To my knowledge (Klaus can confirm), the K870 and K67 are identical, so there's no reason to act rashly.

If it IS a true K87 we're talking about, the difference between the K870/K67 is that the backplates on the K87 are electrically insulated from one another. I'm not sure the difference that would make in a U67, but I bet Klaus knows.

Brad,
I didn't realize that the K87 and K67 were acoustically and physically the same capsule. All else being equal I would agree that one should go for new (or NOS) when possible, rather than a re-skin. I was left with the impression years ago that they were different capsules. OTOH, I think you should listen to my reskin before dismissing the value of the service. I have two otherwise original 67's, both of which I certainly can't tell apart in a blind test, when comparing the capsules. I have had a few other engineers comment on this too. I seriously doubt even few could tell them apart.

FWIW, for some capsules its a moot point anyways. For the CK12, KM5x series, M7, etc) it's either re-skin or throw it in the trash.
Title: Re: Neumann U67- capsule original or not?
Post by: klaus on January 08, 2016, 04:43:59 PM
Brad,
I didn't realize that the K87 and K67 were acoustically and physically the same capsule. (...) I was left with the impression years ago that they were different capsules.

They are not physically the same capsule (in K87 insulating, rather than conductive, backplate spacer material, additional insulating sleeves over the backplate mounting screws), but they are dimensionally and sonically identical during any given capsule era.
Title: Re: Neumann U67- capsule original or not?
Post by: soapfoot on January 08, 2016, 05:31:08 PM
Brad,
I didn't realize that the K87 and K67 were acoustically and physically the same capsule. All else being equal I would agree that one should go for new (or NOS) when possible, rather than a re-skin. I was left with the impression years ago that they were different capsules. OTOH, I think you should listen to my reskin before dismissing the value of the service. I have two otherwise original 67's, both of which I certainly can't tell apart in a blind test, when comparing the capsules. I have had a few other engineers comment on this too. I seriously doubt even few could tell them apart.

FWIW, for some capsules its a moot point anyways. For the CK12, KM5x series, M7, etc) it's either re-skin or throw it in the trash.

Sounds interesting, Dusk. I wish I was close enough to you to hear it.

I've heard a Thiersch M7 reskin and a Drefahl K47 reskin.  Neither of them approached the sound of a good original. In one case (I won't say which), it was on a mic that was a candidate for purchase, and was so obviously inferior to expectations that ensuing questions revealed the reskin.
Title: Re: Neumann U67- capsule original or not?
Post by: duskb on January 08, 2016, 05:58:47 PM
Sounds interesting, Dusk. I wish I was close enough to you to hear it.

I've heard a Thiersch M7 reskin and a Drefahl K47 reskin.  Neither of them approached the sound of a good original. In one case (I won't say which), it was on a mic that was a candidate for purchase, and was so obviously inferior to expectations that ensuing questions revealed the reskin.

Well, next time you're in LA look me up when you have a few free hours and I'll let you hear it for yourself. I didn't realize how lucky I was that these two randomly selected 67's would work so well as a stereo pair, especially given that one was a re-skin. I've been using them for over a decade in all sorts of stereo situations and, aside from the fact that one does tend to have a buzz that I haven't gotten around to sourcing, I can't tell them apart.

I have a third in my possession with a very early serial that has a drier and tubbier sound to it. It's really nice and I believe the capsules are the same but they could not sound any more different.
Title: Re: Neumann U67- capsule original or not?
Post by: klaus on January 08, 2016, 06:52:26 PM
(...) I think you should listen to my reskin before dismissing the value of the service. I have two otherwise original 67's, both of which I certainly can't tell apart in a blind test, when comparing the capsules.

Who did the work? I am skeptical about claims that third-party re-diaphragming of Neumann capsules, regardless the type, would be comparabe to a healthy original. The closest (still no cigar) that anyone has ever come in my estimation is Siegfried Thiersch's nickel diaphragms for KM54/56. His Mylar and PVC work, on the other hand, I found not up to par to the sonic quality of Neumann capsules/diaphragms.

Title: Re: Neumann U67- capsule original or not?
Post by: duskb on January 11, 2016, 02:51:20 PM
Who did the work? I am skeptical about claims that third-party re-diaphragming of Neumann capsules, regardless the type, would be comparabe to a healthy original. The closest (still no cigar) that anyone has ever come in my estimation is Siegfried Thiersch's nickel diaphragms for KM54/56. His Mylar and PVC work, on the other hand, I found not up to par to the sonic quality of Neumann capsules/diaphragms.

My 67 was reskinned by Doug Walker in Canada. I would never go so far as to say that it's impossible for anyone to tell the difference but I have yet to find anyone who can (or has been able to) tell them apart. Perhaps someone who spends alot of time listening for those nuances in a controlled environment would be able to pick it out but unfortunately it's a moot point because none of you guys live close enough to give them a listen.

(BTW, that reassures me about the KM 54. I have a pair that need new skins and I've been reluctant to get them redone. They are unusable otherwise.)
Title: Re: Neumann U67- capsule original or not?
Post by: klaus on January 11, 2016, 04:18:12 PM
Hello dusk,
Thanks for your post. My experience with Doug's reskinning work has not been so positive. Doug, fine gentlemen that he is, in my opinion has so far not succeeded in recreating or approximating Neumann's quality of sound.

I am hopeful, though, that, given the many people who currently attempt rediaphragming, one of them will eventually succeed.

Aside of the eternal desire by all of us to save money, I am mystified why anyone would buy inferior third-party replacement products when the originals are still made.
Title: Re: Neumann U67- capsule original or not?
Post by: Jim Williams on January 11, 2016, 04:32:57 PM
Probably the same reason some would buy the Epiphone Les Paul over a Gibson?

I suspect for many that close enough is a cigar.
Title: Re: Neumann U67- capsule original or not?
Post by: SDVIG on June 10, 2016, 08:22:24 AM
Hello everybody.
I got access to the microphone, and I want to continue.
The microphone was repaired.
It was the replacement of one resistor 2.2 megohm to 2 resistors - 1 megohms & 1.2 megohms. (russian mlt resistors)
As a result, I watched three stages mic life.
A) The microphone worked and had a certain sound.
B) The microphone worked and had the same particular sound, but the low output level.
C) The microphone was fixed and running, but it has a different sound and a normal output level.
The microphone was repaired a specialist in musical equipment,
but he is not the master of the microphone.
He checked the voltage, and said that everything is within the permissible norm.
Interestingly replacement resistor could so dramatically change the sound of the microphone?
The sound of the microphone before repair I liked more.
But I'm not sure.
Why paragraphs A) and C) do not match?
PS:
The head is not touched during repairs.
Title: Re: Neumann U67- capsule original or not?
Post by: SDVIG on June 10, 2016, 08:24:07 AM
Schematic & Resistor
Title: Re: Neumann U67- capsule original or not?
Post by: klaus on June 10, 2016, 09:03:53 AM
Hello Sergei,
Was the original 2MΩ resistor positively identified as faulty?

I am unclear why you are saying that somehow now the mic sounds different: In your opening post, you mentioned that you do not have a second U67 to compare the sound of yours to. I understood that to mean that you never heard your mic at full output, and with an original Neumann capsule until these repairs were done?

Replacing either resistors R12 or R13 with 2 smaller ones in series is fine, and would not have changed an original U67's sound. I suspect, that your technician may have done other things to the mic, or, more likely, that, because you had never heard your U67 with an original capsule until these changes were made, you had no good comparison.
Title: Re: Neumann U67- capsule original or not?
Post by: SDVIG on September 27, 2016, 07:57:36 AM
Hello Klaus.
I really can not compare the sound of my 67 with another 67.
I plan to install it in other capsules.
I see at ebay 2 offers.
Can you help me identify capsule with red numbers:

http://www.ebay.com/itm/322267213326?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

because with black you have already done so.

http://www.ebay.com/itm/282186430784?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

http://repforums.prosoundweb.com/index.php/topic,36282.msg536154.html#msg536154

Thanks for the help.

A side:
Title: Re: Neumann U67- capsule original or not?
Post by: SDVIG on September 27, 2016, 11:27:37 AM
B side:
Title: Re: Neumann U67- capsule original or not?
Post by: klaus on September 27, 2016, 02:12:19 PM
The build characteristics point to a 1990 version.

Make sure the seller tucks away the two solder shoes at the ends of the lead-out wires before shipping. As shown, they are dangerously close to the diaphragm and can easily rip it.
Title: Re: Neumann U67- capsule original or not?
Post by: SDVIG on September 28, 2016, 06:36:39 AM
Resolved