R/E/P Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1]   Go Down

Author Topic: KM84 resonates  (Read 845 times)

T12

  • Newbie
  • *
  • Offline Offline
  • Posts: 3
  • Real Full Name: Jim Roelofsen
KM84 resonates
« on: June 14, 2020, 07:10:48 am »

Hi there,

This is my first post on this forum so maybe this topic was already covered, although I could not find it :
I own several KM84 mics for more than 30 years and still use them regulary.
Last week I did a setup and noticed that 3 of them show what I would describe as
microphony but I never expected it with a non tube device...
The sound character is rather sinuso´dal in the mid range ( 1 - 3 kHz.)
Can anyone help me out on this ?

Best regards,

Logged

klaus

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1826
Re: KM84 resonates
« Reply #1 on: June 14, 2020, 11:11:24 am »

Please let us know what kind of microphonics we are talking about, once have you read this post:
https://repforums.prosoundweb.com/index.php/topic,37339.0.html
Logged
Klaus Heyne
German Masterworks«
www.GermanMasterworks.com

T12

  • Newbie
  • *
  • Offline Offline
  • Posts: 3
  • Real Full Name: Jim Roelofsen
Re: KM84 resonates
« Reply #2 on: June 15, 2020, 06:41:23 am »

Sorry for not describing this in my first message :

The pinging sound is heard while soft knocking on the housing/tube and the decay time is rather short.
Hope this helps ?

Best regards.
Logged

klaus

  • Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1826
Re: KM84 resonates
« Reply #3 on: June 15, 2020, 01:43:03 pm »

I addressed that symptom in my opening post: discrete components on the circuit board that are not secured can resonate when excited, and transmit the resonance into the audio of the mic.

The cure: After taking the housing tube off, hold the mic against your ear, ping the body with a finger of your other hand, or a plastic screwdriver, and identify the ringing sound. Now judiciously hold a finger from the hand that is holding the mic to your ear over components until the ringing stops.Identify and locate the component and secure it with a dab of Eclectic E6000.
Logged
Klaus Heyne
German Masterworks«
www.GermanMasterworks.com

T12

  • Newbie
  • *
  • Offline Offline
  • Posts: 3
  • Real Full Name: Jim Roelofsen
Re: KM84 resonates
« Reply #4 on: July 14, 2020, 11:10:25 am »

I addressed that symptom in my opening post: discrete components on the circuit board that are not secured can resonate when excited, and transmit the resonance into the audio of the mic.

The cure: After taking the housing tube off, hold the mic against your ear, ping the body with a finger of your other hand, or a plastic screwdriver, and identify the ringing sound. Now judiciously hold a finger from the hand that is holding the mic to your ear over components until the ringing stops.Identify and locate the component and secure it with a dab of Eclectic E6000.

Thank you very much Klaus for your suggestions.
Last weekend I was able to "glue" capacitors C1, C2, C9 with a few drops of  Eclectic E6000
Ater that problem solved !


Logged
Pages: [1]   Go Up