R/E/P Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1]   Go Down

Author Topic: AKG C12 parts suggestions  (Read 6534 times)

Donn

  • Newbie
  • *
  • Offline Offline
  • Posts: 19
  • Real Full Name: Donn Halliburton
AKG C12 parts suggestions
« on: May 07, 2011, 10:28:13 pm »

Hello all!

I'm having my mic refurbished, and I'd like some suggestions on what brand of parts to use on the top deck of my C12 for the two 250M and 25M resistor and 5000pF, as well as where to obtain them.  Thanks   
Logged

klaus

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1800
Re: AKG C12 parts suggestions
« Reply #1 on: May 07, 2011, 10:33:10 pm »

Do you or do you not have the original parts?

If you do, use them, case closed.

If not, any polystyrene 5nf/200+VDC will do for the pol. voltage filter. On the resistor issue: AKG used different materials, but mostly carbon resistors. Victoreen/Ohmite is one of the main sources of high value resistors these days.
Logged
Klaus Heyne
German Masterworks®
www.GermanMasterworks.com

Donn

  • Newbie
  • *
  • Offline Offline
  • Posts: 19
  • Real Full Name: Donn Halliburton
Re: AKG C12 parts suggestions
« Reply #2 on: May 09, 2011, 03:22:55 pm »

Thanks Klaus!
I've been on the Ohmite website, and in the victoreen series there are several sub groups, such as Super Mox Series, High Voltage Maxi-Mox Series, etc.  May I ask which Which would be the appropriate category/product?
Logged

klaus

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1800
Re: AKG C12 parts suggestions
« Reply #3 on: May 09, 2011, 03:40:49 pm »

My question had not been answered: do you have the original resistors?
Logged
Klaus Heyne
German Masterworks®
www.GermanMasterworks.com

Donn

  • Newbie
  • *
  • Offline Offline
  • Posts: 19
  • Real Full Name: Donn Halliburton
Re: AKG C12 parts suggestions
« Reply #4 on: May 09, 2011, 06:26:38 pm »

Hi Klaus

No I don't.  This mic was purchased as basically a parts mic that I am having restored.  To be honest, I would prefer original parts, but there seems to be great difficulty in obtaining them for two reasons.  First, people don't like to let go of them, or second, they belittle you for even wanting them, and give no guarantees of their functionality (or willingness to test them) if they do have them.  At this point, I just want good components in my mic so I can use it, so I'm asking for specific help and advice.  Thanks for any help you can give.

Donn
Logged

Jim Williams

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 580
Re: AKG C12 parts suggestions
« Reply #5 on: May 11, 2011, 12:03:03 pm »

Ohmite Mini-Mox 300 series metal oxide resistors are excellent choices, small like 1/4 watt resistors and rather quiet compared to carbon designs. They can be bought from Digi-Key or Mouser. You can get them up to 1 gig ohms for about 6 bucks.

For better, Ohmcraft makes the absolute best large value plate resistors, I paid about 2 bucks each for them in 100 piece quantities.
Highly recommended for replacements if you want to lower the resistor noise contibution to the circuits.

5000 pf caps are available in several formulations, some like polystyrene film, some like polypropylene film, some like teflon, oil and paper, silver foil, you name it, someone makes it. That may require some experimentation to find what speaks best for you.
Logged

J.J. Blair

  • Full Member
  • ***
  • Offline Offline
  • Posts: 130
Re: AKG C12 parts suggestions
« Reply #6 on: May 11, 2011, 04:06:13 pm »

Metal oxide is quieter, but it certainly sounds different, to my ears.  Carbon film is what you will find in vintage mics, generally.  It's in a spiral pattern on a ceramic tube. 
Logged

klaus

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1800
Re: AKG C12 parts suggestions
« Reply #7 on: May 11, 2011, 04:21:52 pm »

ALL types, materials and constructions of replacement parts in critical sections of a microphone will be audible to a critical listener if they are not of the exact same type that originally was found in the mic.

Keep that in mind, and if your ears are sensitive to these potential changes, you will need to go through the effort and personally test out alternatives.
If even minute differences in sound are important to you, do not listen to any parts advice, no matter how well-meaning it was given.  In such case, there is no substitute to personal experimentation.  The internets are not an authoritative source for that kind of decision-making.
Logged
Klaus Heyne
German Masterworks®
www.GermanMasterworks.com

Donn

  • Newbie
  • *
  • Offline Offline
  • Posts: 19
  • Real Full Name: Donn Halliburton
Re: AKG C12 parts suggestions
« Reply #8 on: May 20, 2011, 04:13:28 pm »

I've ordered the Ohmite/victoreen products to try, and Vishay has a high voltage product as well (ceramic) that I'm interested in. Finding Carbon products in the 250M range has been a challenge.  Does anyone have any suggestions for sources or brands for carbon resistors? Also, there's carbon composition, and carbon film.  What's the difference, and which is preferred for a vintage mic?
Logged

klaus

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1800
Re: AKG C12 parts suggestions
« Reply #9 on: May 20, 2011, 04:51:41 pm »

Carbon film is a relatively recent development, and in construction more alike a metal film resistor.

What should not be overlooked: the coil effect of some resistor types, where a resistive conductor is spooled over a cylinder. The presence (or absence) of the coil effect is one additional sonic contribution to consider when choosing resistors.
Logged
Klaus Heyne
German Masterworks®
www.GermanMasterworks.com

Donn

  • Newbie
  • *
  • Offline Offline
  • Posts: 19
  • Real Full Name: Donn Halliburton
Re: AKG C12 parts suggestions
« Reply #10 on: May 20, 2011, 09:25:49 pm »

Thanks!  That answers the second question.  The first one was, who makes carbon resistors in the 30M to 250M range?
Logged

J.J. Blair

  • Full Member
  • ***
  • Offline Offline
  • Posts: 130
Re: AKG C12 parts suggestions
« Reply #11 on: May 21, 2011, 05:17:01 pm »

I don't know if calling what I'm referring to as "carbon film" is the correct term them.  Resistors, that were made at least as far back as the '50s, by what mics I've seen them in, have a spiral band or carbon around a ceramic tube.  I've seen these called "carbon glaze." 

I don't know where you find them.  I bought stashes of ones made by TRW in the 60M, 100M and 200M variety, but I have not seen the specifications of 30 or 250. 

I want to mention how much I like PRP resistors, incidentally.  They are metal oxide, I believe, but very nice sounding. 
Logged

Donn

  • Newbie
  • *
  • Offline Offline
  • Posts: 19
  • Real Full Name: Donn Halliburton
Re: AKG C12 parts suggestions
« Reply #12 on: May 22, 2011, 02:07:01 am »

I want to mention how much I like PRP resistors, incidentally.  They are metal oxide, I believe, but very nice sounding.

Thanks, J.J.  I've looked into the PR9437 Series, which is their "high voltage" series.  The closest I could find to C12 specs was 50M (for the 30M) and 300M (for the 250M's).  Are these what you had in mind, or is there another series I'm unaware of?

Logged
Pages: [1]   Go Up