Welcome To the Hoffman Amplifiers Forum

September 06, 2025, 10:00:19 am
guest image
Welcome, Guest. Please login or register.
-User Name
-Password



Hoffman Amps Forum image Author Topic: Fender Princeton 69 non reverb - total rebuild - how much in labor?  (Read 1321 times)

0 Members and 1 Guest are viewing this topic.

Offline spunko

  • Level 2
  • **
  • Posts: 128
  • I love Tube amps
Hello, I know is a tricky question, but I haven’t done a total rebuild yet.
My client gave me this amp and is a total mess, but it was working well for many years, until it smoked in action.
The amp was ON and being played, then electrical power went off, and immediately the generator from the building started working, and the amp went into smoke (owner put a 4A fuse in it :sad2: )

Power transformer was fried, but I have it already rewinded and is up to spec.
Also the rectifier tube went bad, it makes a lot of sparks inside.

Well, it’s been recapped, and sort of repaired. The amp is working again, but is a ticking bomb.
When installing back the PT at least 3 wires broke off in different places from the board. When in operation mode I did the plastic stick test, poking around and then the negative bias wire broke off.

Is imposible to trust any single wire in that amp.
The owner doesn’t know when it was rebuilt, but he thinks the amp was is a fire like 20 years ago and have been working like that until the electrical power issue.

I suggested a total rebuild, he is kinda against it, because he likes his sound just like that, but I can’t warranty anything with the amp in that state.

Sorry for the long post.

So, how much would be for a total rebuild, just labor?
No fancy chasis finish, or comsetics at all, no spare parts.

Thank you very much.
« Last Edit: February 10, 2025, 02:14:06 pm by spunko »

Offline bmccowan

  • Level 3
  • ***
  • Posts: 1744
  • Better builder than player
Hoffman Amps Forum image
Re: Fender Princeton 69 non reverb - total rebuild - how much in labor?
« Reply #1 on: December 03, 2024, 09:46:06 pm »
IMO there are way too many variables to answer that question. What does total rebuild mean to you? New board? All new wiring? Pots? Sockets? Jacks? etc. Are you fast? Slow? If you have never done one, you are inexperienced. Given that, is it fair to charge what an experienced tech would charge?
The only two ways I can think of to calculate this is to use a spreadsheet and enter each task - estimate the time for each task. Add it up and freak out.
Another way is to research the difference in price of a completed kit and a parts kit from established vendors - Allen Amplification and Ceriatone for example, to get a ballpark idea.
Since you have never done a complete rebuild, I suggest you do it cheap as a learning experience.
« Last Edit: December 03, 2024, 10:22:33 pm by bmccowan »
Mac
“To my surprise, when I opened my eyes, I was the victim of a great compromise.”
John Prine

Offline Latole

  • Level 4
  • *****
  • Posts: 2522
Hoffman Amps Forum image
Re: Fender Princeton 69 non reverb - total rebuild - how much in labor?
« Reply #2 on: December 04, 2024, 03:03:11 pm »
Not less the $500. IMO

Offline bmccowan

  • Level 3
  • ***
  • Posts: 1744
  • Better builder than player
Hoffman Amps Forum image
Re: Fender Princeton 69 non reverb - total rebuild - how much in labor?
« Reply #3 on: December 04, 2024, 05:19:31 pm »
That seems reasonable. I'm pretty slow, so I'm glad I do not do this for a living.
I hope your client gives you the go. The amp deserves to be put right.
Not that you asked, but I would:
Have a new board made by Doug.
Remove the old board, tube sockets and wiring except tranny leads.
Clean the chassis and brass plate.
Clean and tighten pots and jacks.
Reinstall the trannies (can we still use that term?)
Follow a confirmed Fender layout. I suspect a blackface has better lead dress, but with Princetons there's not much differed.
Populate the new board with new components.
Add cloth covered leads following the proper color scheme.
Install Belton sockets.
Install new filter caps and dropping resistors.
Solder it up and go through whatever testing procedure you use.
I'm guessin that would take me 12-15 hours. But I am slow and easily distracted.
Mac
“To my surprise, when I opened my eyes, I was the victim of a great compromise.”
John Prine

Offline AlNewman

  • Level 3
  • ***
  • Posts: 852
  • I love Tube amps
Hoffman Amps Forum image
Re: Fender Princeton 69 non reverb - total rebuild - how much in labor?
« Reply #4 on: December 04, 2024, 06:28:42 pm »
I agree, it is a lot of work.

I think bmccowan has a good strategy for a complete rebuild.  Myself, I would be more in the 16 hour minimum for labour, plus sourcing and ordering parts, which if you don't have them on hand can take a couple hours by itself.

It depends on what you think your time is worth.  And of course, parts and shipping would be extra.  It would definitely be a learning experience, if you would like to make some extra cash, pick an affordable number that you can get paid for your hobby.

If you're doing it as a business, you should already know these numbers.


 


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