R/E/P Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1]   Go Down

Author Topic: U67 Coupling Capacitor Type  (Read 4777 times)

Je55

  • Newbie
  • *
  • Offline Offline
  • Posts: 17
  • Real Full Name: Jess Jackson
U67 Coupling Capacitor Type
« on: March 07, 2014, 08:45:09 pm »

Dear Klaus & Friends,

Klaus, hope your well. You stated in the past that the Neumann U67 coupling capacitor is a Siemens/AEG dry polarized electrolytic 1µf/250v. Is it marked 'Siemens AEG', or are those two different versions?

I have read elsewhere that the cap is a bipolar electrolytic, is this the same thing?

I'm looking for a NOS version of this cap, if not this exact cap on eBay etc...
Also, is there a modern alternative or could you please supply me with further information that would assist my search for something, please?

Also looking for an original BV12 (U67 transformer), if anyone knows someone who has one for sale, would be greatly appreciated.

Greatly appreciated,

Jess
Logged

klaus

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1654
Re: U67 Coupling Capacitor Type
« Reply #1 on: March 07, 2014, 09:27:26 pm »

You stated in the past that the Neumann U67 coupling capacitor is a Siemens/AEG dry polarized electrolytic 1µf/250v. Is it marked 'Siemens AEG', or are those two different versions?
The correct writing on the capacitor is a capital "S" superimposed on a capital "H", which stands for "Siemens & Halske" the German manufacturer of, among other things, electronic components, both past and present. AEG is a different German electric goods manufacturer, which also marketed electrical machinery and components of third parties of all kinds, until 1967, when it was merged with Telefunken, then later bought by Daimler Benz. I do not recall ever seeing AEG's markings on post World War II capacitors.

Quote
I have read elsewhere that the cap is a bipolar electrolytic, is this the same thing?
I do not recall ever seeing a bipolar (non-polarized) electrolytic capacitor in Neumann microphones of that era. I believe they were all polarized, with a (+) or (-) indicating the polarity. Though polarized and bipolar are technically not the same, both can be used in condenser mics as coupling capacitors, as long as you observe the correct polarity when using the polarized type.

Quote
I'm looking for a NOS version of this cap, if not this exact cap on eBay etc...
Also, is there a modern alternative or could you please supply me with further information that would assist my search for something, please?
You sometimes find new old stock of a Siemens electrolytic of the type used in U67 on German eBay. Finding the right capacitance though, (between 1.0 and 2.2mfd @>200VDC) is not going to be easy. You can of course readily use any capacitor in the 1.0mfd region that fits into the cramped space underneith the mic's main circuit board. Another issue for selection will be sound: every capacitor type and even brand sound different. That difference may range from imperceptible to obvious. There are many ongoing discussions in various forums about the sonic quality and other merits of capacitor types. In U67 applications I usually use a high quality film and (aluminum-) foil-type which I selected after many years of trials, errors, revisiting previous choices, which are also influenced by value, voltage and sizing limitations, etc. Unfortunately the quality of the capacitor I use dictates rearranging some components, due to its size. Not recommended for the faint of heart.

Quote
Also looking for an original BV12 (U67 transformer), if anyone knows someone who has one for sale.
That will be close to impossible. The transformer was not offered by Neumann as a spare part after the demise of the model.
Logged
Klaus Heyne
German Masterworks®
www.GermanMasterworks.com

Je55

  • Newbie
  • *
  • Offline Offline
  • Posts: 17
  • Real Full Name: Jess Jackson
Re: U67 Coupling Capacitor Type
« Reply #2 on: March 07, 2014, 10:20:24 pm »

Thanks Klaus,

Based on your info I actually just found this which looks like its the exact capacitor but obviously wrong values.

http://www.ebay.de/itm/5-x-Siemens-Kondensator-MKL-0-22-F-100V-/151015843361?pt=Bauteile&hash=item23293ee621

I found another one 1uf at 160v but 160v won't suffice, correct?
And another at 250v but only 0.47mfd. grr

At the moment in my u67 clone I have a Green Nos Ero MKT 1813 1uf 250v but I'm about to build a u67 inside a u87 body and wanted to keep this one as close to factory spec as possible. Given that I can't find one in the near future, I'll most likely use one of the larger MKT types.

There was a BV12 on uk ebay I missed recently. It had the yellow covering, obviously from the re run of u67 that senheiser did not long ago.

Cheers,

Jess
Logged

klaus

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1654
Re: U67 Coupling Capacitor Type
« Reply #3 on: March 07, 2014, 10:32:11 pm »

There was a BV12 on uk ebay I missed recently. It had the yellow covering, obviously from the re run of u67 that senheiser did not long ago.
Could not find anything about a U67 transformer on British eBay. What did it go for?
Logged
Klaus Heyne
German Masterworks®
www.GermanMasterworks.com

Je55

  • Newbie
  • *
  • Offline Offline
  • Posts: 17
  • Real Full Name: Jess Jackson
Re: U67 Coupling Capacitor Type
« Reply #4 on: March 07, 2014, 10:40:04 pm »

Logged

Je55

  • Newbie
  • *
  • Offline Offline
  • Posts: 17
  • Real Full Name: Jess Jackson
Logged

Je55

  • Newbie
  • *
  • Offline Offline
  • Posts: 17
  • Real Full Name: Jess Jackson
Re: U67 Coupling Capacitor Type
« Reply #6 on: March 30, 2014, 02:44:49 pm »

I'm answering my own questions after some research and I think those are metalized film and not electrolytic. i'm looking to achieve the electrolytic sound as found in the originals, its more snappy and suites faster style singing & rapping better.

Does anyone have a good modern alternative?

Cheers :)

J
Logged

klaus

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1654
Re: U67 Coupling Capacitor Type
« Reply #7 on: March 30, 2014, 09:27:05 pm »

I would approach this subject with a bit more flexibility: Why not try a few different types, at the same value, and see which capacitor interacts with, and reacts best to, the  capsule, and the tube?

Both, and especially the capsule, imprint a fairly big character on the mic, to the point that, if you are strictly going by theory or common opinion, you may make a choice that ends up being counterproductive to your goal of achieving balance:

A certain type of capacitor may put an already bright capsule over the edge into unpleasantness; likewise, choosing a fairly mellow capacitor mated to a mellow capsule may make the mic sound overly sluggish.

Nothing wrong with experimenting, especially when it comes to such a relatively inexpensive item like a coupling capacitor.
Logged
Klaus Heyne
German Masterworks®
www.GermanMasterworks.com

Je55

  • Newbie
  • *
  • Offline Offline
  • Posts: 17
  • Real Full Name: Jess Jackson
Re: U67 Coupling Capacitor Type
« Reply #8 on: April 01, 2014, 08:18:11 am »

This is true,

I built the u67 inside a u87ai body so its running the Neumann k67 capsule that came with it.

Im running a nice quiet nos Telefunken ef86 and olivers t67 transformer despite my search for a bv12. Olivers or max's bv12 may be the next install.

At the moment I'm running a nos ero MKT 1822 1uf coupling cap.

With this setup the mic seems to have a little too fast transient and a sharp 14-16k kick on the transient. Its very bright and you can't hear too much of the u67's natural de-emphesis feedback circuit kicking in as much us the originals.

I think that the t67 has a sharper top end than a bv-12. I kind of like the electrolytic caps for their speed and spitty kind of filtered top end. They don't sound the best when solo'd or on their own but they sit in the mix really well as original u67's and u87's do.

Ive got quite a few different film and pio type caps here.. I might actually give try a pio next.

Best,

J
Logged
Pages: [1]   Go Up