Welcome To the Hoffman Amplifiers Forum

September 07, 2025, 05:25:10 am
guest image
Welcome, Guest. Please login or register.
-User Name
-Password



Hoffman Amps Forum image Author Topic: output impedance mis-match on a TOS  (Read 2122 times)

0 Members and 1 Guest are viewing this topic.

Offline oldhippy

  • Level 1
  • *
  • Posts: 29
Hoffman Amps Forum image
output impedance mis-match on a TOS
« on: April 16, 2012, 07:14:44 pm »
greetings...
I'm thinking about building a TOS board to put in a 5F6a chassis, using the existing iron. I've ran the 5f6a with only 1 ea. 8 ohm spkr to reduce the volume despite the 2 ohm OT, with no problems. Can I do the same with the TOS innards without causing a problem or will the mis-match be more of an issue? Thanks in advance.

Offline sluckey

  • Level 5
  • *******
  • Posts: 5075
    • Sluckey Amps
Hoffman Amps Forum image
Re: output impedance mis-match on a TOS
« Reply #1 on: April 16, 2012, 07:46:55 pm »
If you use the same output tubes, the results should be the same.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline oldhippy

  • Level 1
  • *
  • Posts: 29
Hoffman Amps Forum image
Re: output impedance mis-match on a TOS
« Reply #2 on: April 18, 2012, 07:30:48 pm »
sluckey, thnx for the reply. I mis-posted, I've been running a 4 ohm spkr rather than the 8 ohm I stated earlier. My 5f6a is fixed bias and the TOS I'm looking at is cathode biased. Not an issue? thanks

Offline HotBluePlates

  • Global Moderator
  • Level 5
  • ******
  • Posts: 13127
Hoffman Amps Forum image
Re: output impedance mis-match on a TOS
« Reply #3 on: April 18, 2012, 08:00:12 pm »
Nope. The tubes, OT and speaker see all this as the same situation as you had in your original 5F6A circuit.

 


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


password