The No.1 Website for Pro Audio
 Search This Thread  Search This Forum  Search Reviews  Search Gear Database  Search Gear for sale  Search Gearslutz Go Advanced
RCA 44 question Ribbon Microphones
Old 23rd March 2019
  #1
Gear Head
 
boomwhack's Avatar
RCA 44 question

Is anyone familiar with these controls (or jumpers) on an RCA 44 mic? I’m guessing “M” is music and “V” is voice (and that it is currently set to “M”), but what is 50? Thanks for any info you can provide.
Attached Thumbnails
RCA 44 question-15413328-e9c5-4134-a6f4-185933b2e3d7.jpg  
Old 23rd March 2019
  #2
Here for the gear
 
al_net77's Avatar
Maybe fifty-fifty from M and V?
Old 23rd March 2019
  #3
Lives for gear
 
toledo3's Avatar
 

It progressively tames the proximity effect/reduces low end, with M having most (and being the “natural” setting), V having least.

IIRC, some have M, V1 and V2 on the underside, not M, 50, V. I think 50 must be equivalent to V1.
Old 23rd March 2019
  #4
Lives for gear
 
12ax7's Avatar
 

Quote:
Originally Posted by boomwhack View Post
Is anyone familiar with these controls (or jumpers) on an RCA 44 mic? I’m guessing “M” is music and “V” is voice (and that it is currently set to “M”), but what is 50? Thanks for any info you can provide.
You are correct about the meanings of "V" & "M".

As for the designation of "50", this refers to the "50 ohms" setting. (The other setting is "250 ohms".)

From the original manual:
To alter the frequency response proceed as follows: A small circular hole will be found in the cover plate of the transformer casing. Through this hole will be visible the letter “V” (voice) or the letter “M” (music), depending on whether the microphone is at the time adapted for vocal pick-up or for musical pick-up. Vocal pick-up requires the use of a jumper (upon which appears the letter “V”), which is to be placed across the two terminals marked “M” (music), located on the terminal block within the transformer housing. Access to this terminal block is obtained by removing the cover plate of the transformer housing. When the jumper “V” is used, it connects a reactor in parallel with a part of the transformer winding (when the 250-ohm connections are used), or with all the transformer winding (when the 50-ohm output connections are used). See the schematic diagram, Figure 6.
Here's the diagram:
Here's a .pdf file of the entire original manual:
RCA 44b.pdf
.
Old 23rd March 2019
  #5
Gear Head
 
boomwhack's Avatar
Thanks for the info!
Old 23rd March 2019
  #6
Lives for gear
 
12ax7's Avatar
 

...So for those who may be following along at home:
BoomWhack's photo shows this mic wired for 250 ohms and no bass roll-off (the "M" setting):
.
Old 24th March 2019
  #7
Lives for gear
 
emrr's Avatar
Oh cool, you got an NBC modified model with the straps on the outside for easy adjustment.
Old 24th March 2019
  #8
Gear Head
 
boomwhack's Avatar
And if memory serves correctly, my dad got it for about 300 bucks from NBC back in the 80’s when everyone was jumping on the digital train!

Last edited by boomwhack; 25th March 2019 at 05:50 AM..
Old 25th March 2019
  #9
Lives for gear
 
andersmv's Avatar
 

Quote:
Originally Posted by boomwhack View Post
And if memory serves correctly, my dad got it for about 300 bucks from NBC back in the 80’s when everytwas jumping on the digital train!
He probably overpaid at the time...

Top Mentioned Products
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Similar Threads
Thread
Thread Starter / Forum
Replies
notbadproduction / High End
10
Northamusi / Geekslutz Forum
8
styleOsound / So Much Gear, So Little Time
0
drBill / High End
6
Abery Clark / High End
0

Forum Jump
Forum Jump