Welcome To the Hoffman Amplifiers Forum

September 06, 2025, 12:40:15 pm
guest image
Welcome, Guest. Please login or register.
-User Name
-Password



Hoffman Amps Forum image Author Topic: Lamp limiter- nada  (Read 1987 times)

0 Members and 1 Guest are viewing this topic.

Offline mrhudson27

  • Level 1
  • *
  • Posts: 8
  • I love Tube amps
Hoffman Amps Forum image
Lamp limiter- nada
« on: June 06, 2022, 12:52:10 pm »
Hey, all. Another neophyte query: attempted to power up a 90’s Ampeg Reverberocket R50H head that has been stored for > 10 years, fully operational when shelved. Plugged into lamp limiter (homemade, proven track record) and NO light. Not bright, not dim- nothin’. Amp no power up. About to pull chassis & check fuse. I get short vs no short, but what does darkness tell me?

Flogging & belittlement anticipated and welcomed (in a time crunch- haven’t researched threads here yet)

Offline sluckey

  • Level 5
  • *******
  • Posts: 5075
    • Sluckey Amps
Hoffman Amps Forum image
Re: Lamp limiter- nada
« Reply #1 on: June 06, 2022, 01:08:04 pm »
I get short vs no short, but what does darkness tell me?
Darkness tells you that either there is no current flowing (open circuit) or the current is so small that it's not enough to make the bulb filament glow.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline kagliostro

  • Level 5
  • *******
  • Posts: 7739
Hoffman Amps Forum image
Re: Lamp limiter- nada
« Reply #2 on: June 06, 2022, 01:15:52 pm »
A broken fuse ?

Oxidation ?

Broken wire in the Line to Amp path ?

Who can Say

You must practice some further investigation

Franco




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

Offline Latole

  • Level 4
  • *****
  • Posts: 2522
Hoffman Amps Forum image
Re: Lamp limiter- nada
« Reply #3 on: June 07, 2022, 02:52:53 am »
Is your bulb lamp is good ?

Your bulb lamp curent limiter; what kind of bulb ? You need a old style incandescent bulb; 75 to 100 watts.

Did it work ( light) on a good working amp ?

After you say yes, check the amp

Offline Keppy

  • Level 1
  • *
  • Posts: 80
Hoffman Amps Forum image
Re: Lamp limiter- nada
« Reply #4 on: June 07, 2022, 09:34:14 pm »
I check my light bulb limiter by plugging a heat gun into it. That draws enough current to get the bulb nice & bright.


Aside from lighting up if there's a short, the limiter doesn't tell you much. It's there to keep you from blowing fuses & circuit breakers. If it doesn't light up, it's time to start checking voltages within the amp.

 


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