Welcome To the Hoffman Amplifiers Forum

September 06, 2025, 09:53:13 am
guest image
Welcome, Guest. Please login or register.
-User Name
-Password



Hoffman Amps Forum image Author Topic: 61' Fender Super - No volume  (Read 6255 times)

0 Members and 1 Guest are viewing this topic.

Offline hatchhh

  • Level 1
  • *
  • Posts: 19
Hoffman Amps Forum image
61' Fender Super - No volume
« on: April 03, 2010, 03:29:07 pm »
Hi:

I have a 61 super 6G4A - I have been going through trying to right some of the poor choice of capacitors and wiring that the previous owner had done to the amp.   I have been following the layout religiously, but when I got done, and put it all back together I get no volume in either the normal or vibrato channels.  Are there any likely suspects that I should check first?  Like I said I tried to follow layout, but I am relatively new to this, so I probably missed something.

Thanks for the help.

Offline tubesornothing

  • SMG
  • Level 4
  • *****
  • Posts: 2664
  • A strong spark ought to bear calamities...
Hoffman Amps Forum image
Re: 61' Fender Super - No volume
« Reply #1 on: April 03, 2010, 03:35:27 pm »
Nothing coming from the speaker? No noise, a hiss or anything? 

Check the obvious:
- right tubes in the right places
- speaker plugged in
- input working correctly (e.g. guitar and cable)
- check all your heater voltages
- check your B+ voltages

If still nothing, post all your tube voltages, preferably with the schematic so we know which tube is which.


Offline Colas LeGrippa

  • Level 4
  • *****
  • Posts: 2198
  • MAKE LOVE NOT WAR
Hoffman Amps Forum image
Re: 61' Fender Super - No volume
« Reply #2 on: April 03, 2010, 04:41:44 pm »
check the speaker out jack , are the 4 speakers all  connected properly ?

C.
Don't miss the Woodstock experience : ''FORTY YEARS AFTER'' at Club Soda,  in Montreal, august the 17th and 18th and october the 27th. Fifteen musicians onstage.  AWESOME !
P.S.: call me Alvin.

Offline HotBluePlates

  • Global Moderator
  • Level 5
  • ******
  • Posts: 13127
Hoffman Amps Forum image
Re: 61' Fender Super - No volume
« Reply #3 on: April 03, 2010, 04:45:41 pm »
Also, although hacked, it presumably worked before you corrected things. So check 3 times for a wire running to the wrong eyelet (especially underboard wires) and for cold solder joints.

A fast method to test for where the amp stops/starts working:
Get a small screwdriver with an insulated handle, or use a meter probe. Carefully touch the grid of the output tubes with the tip of the probe with the amp on. Be very careful about working around live voltage and be sure not to short anything with the probe tip. If the amp is functioning from the output tube grid to the speaker, you should hear a small click or pop when you touch the grid with the probe. Did I say that an insulated handle is mandatory?

Next, go to the plate pin of the phase inverter, and repeat. You should hear the same click/pop at the speaker. There's high voltage here, and an insulated handle is mandatory. Are you getting the impression this is important?  :grin:

Repeat this touch test at the grid of the phase inverter, and you should hear a louder click/pop. That's because of the amplification of the stage. Continue working backward through the circuit to each previous plate and grid, and the clicks will continue to get louder. When you find the point where you go from getting a click at one test point to no click at the next earlier point, you've found a place where the signal chain is broken. Look for bad solder joints, wires to wrong places, shorts, opens, etc. In a restoration where the amp previously worked, the fault will almost exclusively be builder error. That's normal and we all learn to be more careful the next go round.

This method assumes good voltages throughout the amp. You could do this test in place of measuring voltage, if you're reasonably certain everything is as it should be. Or, you could even combine this test with measuring plate and grid voltages by keeping your ground lead clipped to the chassis while you probe (with 1 hand!) the plates and grids. The click will occur regardless of whether you use a screwdriver or a meter probe.
« Last Edit: April 04, 2010, 02:36:30 pm by HotBluePlates »

Offline hatchhh

  • Level 1
  • *
  • Posts: 19
Hoffman Amps Forum image
Re: 61' Fender Super - No volume
« Reply #4 on: April 04, 2010, 10:32:09 am »
Thanks for the input.  I'll get after it and see what I can figure out.

Offline Maschinenmann

  • Level 1
  • *
  • Posts: 26
Hoffman Amps Forum image
Re: 61' Fender Super - No volume
« Reply #5 on: April 05, 2010, 01:10:35 pm »
check the speaker out jack , are the 4 speakers all  connected properly ?

C.

'61 super is a 2 x 10 combo.....  :wink:

 


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