R/E/P Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1]   Go Down

Author Topic: U-87 mic mod question  (Read 1110 times)

Donn

  • Newbie
  • *
  • Offline Offline
  • Posts: 23
  • Real Full Name: Donn Halliburton
U-87 mic mod question
« on: February 15, 2022, 01:35:10 PM »

Hello,

I have a version 04, and have made the following modifications:

1. Remove HP and LP filters
2. Removed the sub-board, and replaced with a 2N3819 (I located a small stash of Texas Instruments 2N3819s). Biased and good to go.
3. Lowered the capsule polarization voltage to 47VDC.

Is there anything else circuit-wise that can be done that will bring it closer to the pre 04 circuit/pre "A" specs, or make further sonic refinements?

Donn
Logged

RuudNL

  • Full Member
  • ***
  • Online Online
  • Posts: 122
  • Real Full Name: Ruud van Steenis
  • There is a solution for every problem!
Re: U-87 mic mod question
« Reply #1 on: February 20, 2022, 09:52:25 AM »

1 - Do I get the impression that you removed the frequency dependent network altogether? Does it sound 'better' now? (I doubt it...)
2 - As long as you can find a 'good' 2N3819 (there are many fakes nowadays), it might be an improvement. Although some people think the sub-board is better...
Logged

Donn

  • Newbie
  • *
  • Offline Offline
  • Posts: 23
  • Real Full Name: Donn Halliburton
Re: U-87 mic mod question
« Reply #2 on: February 26, 2022, 03:04:42 PM »

1 - Do I get the impression that you removed the frequency dependent network altogether? Does it sound 'better' now? (I doubt it...)
2 - As long as you can find a 'good' 2N3819 (there are many fakes nowadays), it might be an improvement. Although some people think the sub-board is better...

1. As I'm sure you know, all new Neumann's have their infamous high and low pass filters to conform to German broadcasting regulations. They should be the first thing to go with U87Ai used in a music application IMO. I can't imagine any sonic benefit from this additional circuitry outside of voiceovers and broadcast (and I think it's questionable there too).  Fortunately, it's easily removed.

2. The TI 2N3819 is genuine. As for the sub-board being better, I've seen debates over headroom and S/N Ratio, but I wonder how common it is for producers and artists to hear a more musical sound from revisions 04 and 05 with the sub-board. And if Neumann also believed they sounded better, why did they return to the 2N3819 FETS and ditch the sub-boards?

Donn
Logged

klaus

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2210
Re: U-87 mic mod question
« Reply #3 on: February 27, 2022, 12:51:39 PM »

Agree with your second point.
Your first point is factually incorrect: Neumann's version of the Braunmühl-Weber double-backplate capsule design requires[/] attentuation of the high frequencies in the mic processor. That attenuation tames an extreme high frequency rise (±9db@9kHz).

Without it, the mic will be offensively bright and unmusical.
Logged
Klaus Heyne
German Masterworks®
www.GermanMasterworks.com
Pages: [1]   Go Up
 



Site Hosted By Ashdown Technologies, Inc.

Page created in 0.044 seconds with 20 queries.