Please Help My Tube Microphones! - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 5th May 2005, 07:13 PM   #1
diyAudio Member
 
Join Date: Feb 2005
Location: Way up north, USA
Send a message via Yahoo to northsiderap
Unhappy Please Help My Tube Microphones!

Hey All....

You've all helped me in the past, so here's another one:

I have two tube microphones, and they both have developed the same problem.

When I turn them on, it sounds 'windy,' referring to the sound of the noise that is made. Of course this noise is bad. When I switch the power off, the noise goes away and the mics are fine for 15 seconds or so while the capsule and capacitors bleed dry.

Is the problem:

A) Bad/Leaky/Microphonic Tube? (one mic is fairly new, the other @30 years old...)

B) Power supply filter caps?

C) Microphone capsule with obstructions which leak capacitance from diaphragm to backplate?

D) Something else...

Any advice would be appreciated, because I will be fixing them myself even if I have to replace each component one at a time (starting with capacitors & tubes)

They are both basic tube mics with a single tube and transformer audio chain....

Get as technical as you want with your answer (and more) because I will be doing this a lot in the future.

Thanks for everyone's great help sofar,
Jim
**Northsiderap.com**
__________________
--> Jim <--
==>NorthSideRap.com<==
  Reply With Quote
Old 5th May 2005, 07:21 PM   #2
Banned
 
Join Date: Jan 2005
What tube are they using ? Got any pics ? It could be A, B would be a huummmmm, C would be more a low volume (need to talk closer to mic) like when you overheat a condenser mic capsule soldering leads to it.
  Reply With Quote
Old 5th May 2005, 07:25 PM   #3
dhaen is offline dhaen  Europe
diyAudio Moderator Emeritus
 
dhaen's Avatar
 
Join Date: Jun 2002
Location: U.K.
Where do they get power from? A common source?
  Reply With Quote
Old 5th May 2005, 07:30 PM   #4
diyAudio Member
 
Join Date: Feb 2005
Location: Way up north, USA
Send a message via Yahoo to northsiderap
Default My mics

The Mics:

One of them is a VERY old Vega Capacitor Microphone which was used originally by drummer Billy Cobham and takes a 6cw4 RCA Nuvistor. The power supply is only caps, audio transformer, power transformer, rectifiers, and resistors. Yes, I do have a new 6cw4 RCA on order already.

The other is a GTAM62 by Alesis (Groove Tube). Takes a military-spec sub-miniature tube. Haven't looked into the guts of the power supply on this one. I think the problem is in the mic, and I will be starting with the tube there, too.

I just thought it was odd that both mics came up with the same problem being so different in age.

The Noise:

The noise is not just hiss, it sounds like wind. It varies in intensity, it literally sounds like a nice breeze blowing on the microphone as if you were recording outside...

The power comes from a standard wall plug. I'm not worried about power distortion, because my father is pretty much an electrical engineer and has reviewed my wiring. I've tried different tube mics on the same outlets as well. No problems with my other tube mics, including an identical GTAM62..

Thanks again,
Jim
**NorthSideRap.com**
__________________
--> Jim <--
==>NorthSideRap.com<==
  Reply With Quote
Old 6th May 2005, 04:53 AM   #5
Enzo is offline Enzo  United States
diyAudio Member
 
Join Date: Sep 2004
Location: Lansing, Michigan
I just had to replace one of those little 5640 tubes in that mic. It was beyond noisy though, after a minute or so it would load down the B+. Groove will sell you the tube through a dealer, or find one elsewhere.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
xfmrs for microphones hitsware Everything Else 1 8th May 2008 10:46 AM
Measurement microphones ShinOBIWAN Multi-Way 18 5th January 2006 10:27 AM
SPL microphones? thylantyr Multi-Way 3 18th June 2005 07:19 PM
Cheap microphones? pentium Everything Else 0 30th October 2003 03:50 PM


New To Site? Need Help?

All times are GMT. The time now is 08:18 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2