Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: TIMBO on December 06, 2025, 04:22:29 am
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Hey guys,
I have the pleasure to restore one of these.
(https://i.imgur.com/elEvy6z.jpg)
(https://i.imgur.com/Ny8fDFY.jpg)
(https://i.imgur.com/oOle2jQ.jpg)
(https://i.imgur.com/21vmwZP.jpg)
(https://i.imgur.com/dTffHUa.jpg)
(https://i.imgur.com/K2yCY5m.jpg)
(https://i.imgur.com/1yzuymZ.jpg)
(https://i.imgur.com/vuFApru.jpg)
(https://i.imgur.com/kGpU7BR.jpg)
(https://i.imgur.com/viKbbrU.jpg)
(https://i.imgur.com/eplUFsE.jpg)
(https://i.imgur.com/DfXAP9D.jpg)
I'll be looking for some guidance on how much I'll need to remove and replace to keep it as original and safe to use
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Hi Timbo,
She's had a bit of a caning! :laugh:
I always fit the Hammond Transformer into them (in my travels in Canberra area they usually come with the 115V tranny and a second Stepdowm 240:115V Typical around120VA)
Can Electro would be suspect and I replace the first 2 Power resistors (Node 2 and 3) with Metal Oxides ( 2 or 3W) You can see charring on one already.
For the Chassis solder points I recommend a 150-180W soldering iron and a good flux (clean off the residue).
I haven't really done any serious chassis restoration, so somebody else my want to chip in.
Hope you have a bit of time free over Christmas.
All the best and it should come out really nice. In my opinion, they are a sweet little amp with a bit of character.
Kind Regards
Mirek
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Thanks mate,
I think I'll totally dismantle the chassis so I can give it a good clean and work back from there.
I'm not 100% sure of the story of this amp, I'm assuming that the original PT was to be replaced with the Ferguson PT166 325-0-325 @60mAs
and Hammond PT was also purchased as it was a better vintage look.
FENDER.PDF (https://el34world.com/charts/Schematics/files/Fender/Fender_vibro_champ_aa764.pdf)
The original schematic calls for 315-0-315 HT so I guess the 325-0-325 will have to be close enough
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Jealous. I saw one at Pete's music shop in King Street, Newtown last time I was in Sydney, but didn't have the spondoolies to collect it at the time.
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Chassis stripped
(https://i.imgur.com/pszbzOs.jpg)
(https://i.imgur.com/na0D7YY.jpg[/img
https://i.imgur.com/WK1acHD.jpg
https://i.imgur.com/sCxvSDW.jpg
And cleaned
https://i.imgur.com/vtUm6pS.jpg
https://i.imgur.com/SvIzdSh.jpg
https://i.imgur.com/bsHHpif.jpg)
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And cleaned
(https://i.imgur.com/bsHHpif.jpg)
(https://i.imgur.com/vtUm6pS.jpg)
(https://i.imgur.com/SvIzdSh.jpg)
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where you riding a Horse with no name when you stumbled on that Sun-baked beauty??
speaking of Sun, it's about time you give it a push back across the equator, bite chilly n dark up Norte'
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Amp looks like it was left out on the front porch in Florida for a year. That's going to be a lot of work - good luck!
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I have a personal 67 Vibro Champ, wasn't as bad as the one you have. I made the decision to replace all the guts with new modern film resistors and metal oxide power R's and updated caps. Sounds fantastic, kept all stock values but that tiny OT at 5 watts does contribute to the amps tone but I had an old 8 watt paper wound SE OT laying around, installed it. The Amp still has the original tone but just a little more clean headroom. The new OT was perfect for 8 ohms too. I took the original baffle bd with the 4 ohm speaker out and replaced it with a Jensen alnico 10" 8 ohm speaker and new baffle bd, grill cloth. I kept the original baffle with the original grill cloth and spk. I didn't butcher the amp, I can easily but it pack to stock, but the old R's and caps are gone, most were toast, kept original PT.
So, might not be an original component Vibro Champ but the OT and baffle can easily be put back, close enough. I guess it depends on the owners choice what to keep or replace but those components look pretty unreliable. Keeps us posted.