Skip navigation

Zibb

Anablog

Paul RakoTechnical Editor Paul Rako looks at analog technology in power supplies, interface, the signal path, and life in general.



   Advertisement

Profile

RSS Feed

  • Add this blog to your RSS newsreader!

Recent Posts

Recent Comments

Most Commented On

Archives

By Category

Analog Design Articles

Blog

Monday, June 15, 2009

Neumann microphone being made video

Jun 15 2009 8:54AM | Permalink |Comments (4) |


Analog wizard Eric Schlaepfer send me this great video of a Neumann microphone being built. You even get a little of a hot tub being vacuum formed at the end. I love Discovery Channel. Now I want to see “How it’s made, in China” to see how they do the cheap knock-offs. Eric noted:

It's very interesting how they mount the diaphragm. It looks like the plastic film is mounted in tension on the hoop when they place it on the brass capsule part. I imagine they also vacuum deposit the gold electrode while the film is tensioned on the hoop.

 


Related entries in: Analog | 

Reader Comments



at 6/15/2009 3:19:43 PM, Rob Bowers said:
When I worked on a U87 (in 1977), the center lead to the diaphragm was only a crimp connection. I worked on it because the crimp had become noisy. I am glad to see that they are soldering it now, though a soldered crimp connection probably would be better.



at 6/15/2009 3:21:59 PM, Paul Rako said:
From my stint at a military contractor I learned that soldered connections are almost always more unreliable than a crimp since the solder turns a stranded wire into a solid wire and that breaks under bending and vibration. You could solder the crimped area if you went to NASA soldering school and maybe not put too much solder in the joint, but a crimped connection should be gas-tight and actually fuse the metal.

That is why AMP crimpers cost 300 bucks. I am a sucker to buy them at the flea market.



at 6/15/2009 3:25:03 PM, Rob Bowers said:
Yeah, I like the BOTH method. I was taught that the real purpose of solder was to exclude gas from the connection. Solder is a lousy (comparatively) conductor and is NOT a mechanical connection.

Yeah NASA soldering means only enough solder to exclude gas. If you couldn’t count see the outer strands in a stranded wire, you were using FAR too much solder. I sure am glad I don’t make my living working to that exacting a standard. I must say though a roll of solder lasts me a long long time.



at 6/15/2009 3:34:47 PM, Stephen Williams said:
It would be interesting to take apart an inexpensive Chinese made condenser mic and see how it differs from the Neumann in construction and quality. I would think that the build quality and materials could potentially rival the Neumann, BUT it will likely be lower as the particular mics are typically built to hit a lower price point and so corners are cut of course. Exactly which corners and how much probably determines the price. They show a lot of hand labor in the Neumann and exactly who is doing it and to what tolerance determines the outcome. A "comparable" Chinese mic might be made by a more varied workforce with less experience and then less rigorous inspection might yield more mics but the specs will vary for each one. It might come down to "if it works at all - ship it".

As to crimping, I have never worked in an environment where Amp or other pro crimping systems were used. I have had the best luck with the typical insulated general-purpose crimp connectors with my now unavailable Vaco 1900 bought at Quement when I worked there in the late 70s. It has 3 sizes of "D" crimp dies above the pivot point. Of course you must look for the seam on the crimp and make sure it is on the larger round section and does not get pressed by the male portion of the crimp. So many of the cheap ones now just flatten the crimp and we have all been there when in desperation we squish one with any available pliers - not good.

When I started to work at Century Stereo and began connecting lots of stranded speaker wires together I asked Bob and Vini (both somewhat my supervisors in charge of procedure) how they would like to see me connect wires together. In my previous early security system installs with Richard, I / we had been literally dragging a Weller soldering gun with AC cord under houses and twisting then soldering and taping our wires together. Bob said use wire nuts; Vini said use crimps (like barrel butt splice crimps). Turns out that Vini had never learned proper wire nut technique and was pre-twisting the wires together and Bob had never used decent "D" crimpers, just flattened them with pliers so they each had negative experiences with the device and so told me to use the opposite one. I was able to successfully use either.

Except on Harleys. If you solder it will fatigue and break as a solid wire as Paul said. If you crimp, each individual strand will eventually fatigue and break individually - no matter how tightly twisted they were to begin with.

I think they may use some special type of wire on the mic diaphragm connection (the exact construction of that wire being another potential quality difference with the Chinese made mics) that is a very flexible very fine strand braid.

Perhaps we should wire our Harleys with all special ultra-fine high strand count braid...


Post a comment



Display Name

Change Image
Before submitting this form, please type the characters displayed above.
Note the letters are NOT case sensitive.


ADVERTISEMENT

About Us   |   Contact Us   |   Free Email Newsletters   |   Free Magazine Subscription  |   Advertising   |   RSSRSS   

©1997-2009 Reed Business Information, a division of Reed Elsevier Inc. All rights reserved.
Use of this Web site is subject to its Terms of Use | Privacy Policy

Please visit these other Reed Business sites