Welcome To the Hoffman Amplifiers Forum

September 08, 2025, 12:52:37 am
guest image
Welcome, Guest. Please login or register.
-User Name
-Password



Hoffman Amps Forum image Author Topic: Headset Adapter MC-385-A do you see any use for it ?  (Read 3338 times)

0 Members and 1 Guest are viewing this topic.

Offline kagliostro

  • Level 5
  • *******
  • Posts: 7739
Hoffman Amps Forum image
Headset Adapter MC-385-A do you see any use for it ?
« on: November 12, 2023, 03:42:46 pm »
Today I recovered a NOS Headset Adapter MC-385-A

I did a search and I find that it has a primary impedance of 3750ohm and a secondary of 600ohm

Do you see a way I can use it in our constructions ?

Thanks

Franco
The world is a nice place if there is health and there are friends

Offline sluckey

  • Level 5
  • *******
  • Posts: 5075
    • Sluckey Amps
Hoffman Amps Forum image
Re: Headset Adapter MC-385-A do you see any use for it ?
« Reply #1 on: November 12, 2023, 03:46:53 pm »
Connect the primary to your SE power amp and the secondary to the phone line.  :icon_biggrin:
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline PRR

  • Level 5
  • *******
  • Posts: 17082
  • Maine USA
Hoffman Amps Forum image
Re: Headset Adapter MC-385-A do you see any use for it ?
« Reply #2 on: November 12, 2023, 04:36:04 pm »
Isolated Line Output for feeding a sound board on the far side of the Colosseum, Stadio Giuseppe Meazza, or Yankee Stadium.

IS it truly isolated? Infinite Ohms from one winding to the other? A headphone adapter does not have to be isolated.

Background: headphones used to be 2K impedance. 1944 was a swing to 600r. Old radios did not change but new headsets were going out as old ones wore-out, so the adapter made new phones work well on existing radios/intercoms.
http://www.752tank.com/TankHelmet.html
« Last Edit: November 12, 2023, 05:10:23 pm by PRR »

Offline kagliostro

  • Level 5
  • *******
  • Posts: 7739
Hoffman Amps Forum image
Re: Headset Adapter MC-385-A do you see any use for it ?
« Reply #3 on: November 12, 2023, 05:19:30 pm »
Thanks Sluckey & PRR

Quote
IS it truly isolated?

I don't know, I'll give a look to this aspect

Franco
The world is a nice place if there is health and there are friends

 


Choose a link from the
Hoffman Amplifiers parts catalog
Mobile Device
Catalog Link
Yard Sale
Discontinued
Misc. Hardware
What's New Board Building
 Parts
Amp trim
Handles
Lamps
Diodes
Hoffman Turret
 Boards
Channel
Switching
Resistors Fender Eyelet
 Boards
Screws/Nuts
Washers
Jacks/Plugs
Connectors
Misc Eyelet
Boards
Tools
Capacitors Custom Boards
Tubes
Valves
Pots
Knobs
Fuses/Cords Chassis
Tube
Sockets
Switches Wire
Cable


Handy Links
Tube Amp Library
Tube Amp
Schematics library
Design a custom Eyelet or
Turret Board
DIY Layout Creator
File analyzer program
DIY Layout Creator
File library
Transformer Wiring
Diagrams
Hoffmanamps
Facebook page
Hoffman Amplifiers
Discount Program