Welcome To the Hoffman Amplifiers Forum

September 07, 2025, 01:45:38 pm
guest image
Welcome, Guest. Please login or register.
-User Name
-Password



Hoffman Amps Forum image Author Topic: Pro Reverb that says it's a Twin?  (Read 2062 times)

0 Members and 1 Guest are viewing this topic.

Offline JB

  • Level 2
  • **
  • Posts: 231
Hoffman Amps Forum image
Pro Reverb that says it's a Twin?
« on: March 27, 2022, 09:27:37 am »
A friend of mine has asked me to repair and service his Fender Pro Reverb.  Apparently the Power switch doesn't work, i.e. shorted on, and now the amp has stopped working.  Not dead, he says the master volume pot makes the speakers crackle when turned, so there's hope.
Anyway, the odd thing is the face plate says it's a silver face Twin Reverb.  The tube chart shows 4 x 6L6.  However this amp only has 2 x 6L6. It appears therefore to be a Pro Reverb. The only schematic that, so far, appears to match is a Fender one that seems to cover the ultra linear versions of the Pro, Super and Bandmaster.   Amp serial number and pots date it to 1977.
Any idea why it would be labelled on the face plate and tube chart as a Twin?  My mate bought it secondhand in 1980 and apart from him saying the power switch had to be replaced once before it appears to be untouched inside.

Offline sluckey

  • Level 5
  • *******
  • Posts: 5075
    • Sluckey Amps
Hoffman Amps Forum image
Re: Pro Reverb that says it's a Twin?
« Reply #1 on: March 27, 2022, 09:42:08 am »
Fender did some crazy stuff with the Pro Reverbs. Can you provide some pics?
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline punkykatt

  • Level 3
  • ***
  • Posts: 1145
  • I love tube amps
Hoffman Amps Forum image
Re: Pro Reverb that says it's a Twin?
« Reply #2 on: March 27, 2022, 09:43:57 am »
They make mistakes from time to time. The person who put the face plate on made the mistake, the person who put the sticker on just looked  at the faceplate is my guess.

Offline JB

  • Level 2
  • **
  • Posts: 231
Hoffman Amps Forum image
Re: Pro Reverb that says it's a Twin?
« Reply #3 on: March 27, 2022, 09:52:02 am »
Fender did some crazy stuff with the Pro Reverbs. Can you provide some pics?
I'll have a go, hold on....

Offline JB

  • Level 2
  • **
  • Posts: 231
Hoffman Amps Forum image
Re: Pro Reverb that says it's a Twin?
« Reply #4 on: March 27, 2022, 10:20:12 am »
Here it is:






Offline sluckey

  • Level 5
  • *******
  • Posts: 5075
    • Sluckey Amps
Hoffman Amps Forum image
Re: Pro Reverb that says it's a Twin?
« Reply #5 on: March 27, 2022, 11:15:37 am »
Definitely a Pro Reverb chassis (only 2 octal sockets) and the voltage selector switch indicates it is an export model.

This looks like the schematic...

     https://el34world.com/charts/Schematics/files/Fender/Fender_ultralinear_pro_rev.pdf
« Last Edit: March 27, 2022, 11:22:16 am by sluckey »
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline JB

  • Level 2
  • **
  • Posts: 231
Hoffman Amps Forum image
Re: Pro Reverb that says it's a Twin?
« Reply #6 on: March 27, 2022, 11:23:18 am »
Yes I'm in the UK so it's the export version and set to 240V.  I wonder if someone put the wrong faceplate on, and then whoever sticks the tube charts read the plate and slapped in the chart for a Twin.
Must have been made late on a friday afternoon...

Offline sluckey

  • Level 5
  • *******
  • Posts: 5075
    • Sluckey Amps
Hoffman Amps Forum image
Re: Pro Reverb that says it's a Twin?
« Reply #7 on: March 27, 2022, 11:28:36 am »
Nah, they only made Pro Reverbs on the midnight shift. Most of the workers loved Cheech and Chong.   :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 JB

  • Level 2
  • **
  • Posts: 231
Hoffman Amps Forum image
Re: Pro Reverb that says it's a Twin?
« Reply #8 on: March 27, 2022, 11:45:22 am »
Nah, they only made Pro Reverbs on the midnight shift. Most of the workers loved Cheech and Chong.   :icon_biggrin:
In which case it's a wonder it ever worked!
And yes I think that is the schematic.  I'm going to recap it, swap out the power and standby switches that he says are both faulty (the power switch does feel a bit odd) and then take it from there.

 


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