Welcome To the Hoffman Amplifiers Forum

September 06, 2025, 04:38:43 pm
guest image
Welcome, Guest. Please login or register.
-User Name
-Password



« previous next »
Pages: [1]   Go Down

Hoffman Amps Forum image Author Topic: Univox U1221 Plate to Plate Resistor Mod  (Read 1598 times)

0 Members and 1 Guest are viewing this topic.

Offline astronomicum

  • Level 2
  • **
  • Posts: 155
Hoffman Amps Forum image
Univox U1221 Plate to Plate Resistor Mod
« on: June 17, 2022, 09:53:42 am »
Working on a U1221 with a 330K resistor placed between the plates of the PI Preamp and the PI. Anybody have any idea what the purpose of this could be? Thanks.
« Last Edit: June 17, 2022, 10:01:03 am by astronomicum »
Hoffman Amps Forum image Logged

Offline sluckey

  • Level 5
  • *******
  • Posts: 5075
    • Sluckey Amps
Hoffman Amps Forum image
Re: Univox U1221 Plate to Plate Resistor Mod
« Reply #1 on: June 17, 2022, 11:31:38 am »
I'm guessing it's a NFB loop. It's not on the schematic.
Hoffman Amps Forum image Logged
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!
Pages: [1]   Go Up
« previous next »
 


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