1976 Fender Vibrolux refresh help

[akabek]

I recently picked up a 1976 Vibrolux amp. The previous owner removed the earth 3rd prong from the plug so I would like to replace it. Most of the components seem to be original but there appears to be a couple additions to the amp. I would like to replace the aged electrolytic caps to avoid future issues. There are a couple of resistors on the 6L6 sockets exposed to heat so they may be replacement candidates.

The amp controls and speakers work. The vibrato channels have some noise so I will need to check the tubes.

Attached is the layout and schematic diagram and a couple pictures of the components.

[akabek]

The top pic is of a stock 76 Vibrolux I found online. The bottom pic is my amp where I circled two areas that appear to be altered.

In the top red circle there are green leads (running to the right) connected to a post screwed to chassis and a very thin red wire running from the indicator lamp to the post. According to the stock photo the green leads should be connected to the indicator lamp. Any idea of the purpose of this mod? Is it to get a cleaner ground connection?

The lower red circle has two white wires soldered to a post (not found in the stock pic) that runs to the fuse and power on switch. Is this safety feature? Should I move the green wires back to the indicator lamp and remove post with the white wires?

[akabek]

I pulled the post with the white wires to get a better pic. I am not sure if it a resistor on there.

[bepone]

all electrolytic capacitors needs replacement.. another critical point are film capacitors after the PI to the output tubes, they need to be replaced too.. all those moves are preventive and cheap..all elcos are too old and can fail anytime in the future.

on other positions film caps should be measured for DC leaking in amp ON state, and replaced accordingly

[bepone]

for the added fuse, check what is this and why is there

[Ten Over]

I pulled the post with the white wires to get a better pic. I am not sure if it a resistor on there.

That's a thermal fuse. Fender put those in there for amps sold in Canada.

[akabek]

Should I leave the thermal fuse and ground changes as is or remove them?

[pdf64]

Should I leave the thermal fuse and ground changes as is or remove them?

'Ground changes'? You mentioned that the ground pin had been removed from the mains plug. That certainly needs sorting, eg fit a new plug.
Replacing the mains cable might be more difficult, as a big bertha iron might be needed to reflow the soldered chassis connection properly.

[akabek]

The comment I made about the ground was in reference to post 19, the pic with the top red circle area with the green leads. In my amp their are green leads connected to a terminal and screwed down to the chassis. I posted a pic of another amp where those green leads are connected to the indicator light which matches the layout diagram. I assume the green leads are for ground. I am trying to decide if I should leave it or move them back to the indicator light. Someone mentioned above the Canadian amps were built slightly different.

I will definitely replace the mains cord with a 3 prong. Hopefully one of my irons will have enough heat for the earth ground wire.

[sluckey]

I will definitely replace the mains cord with a 3 prong. Hopefully one of my irons will have enough heat for the earth ground wire.

No need to replace the cord. Just put a new 3-prong AC plug on the end of the existing cord.

[Ten Over]

Should I leave the thermal fuse ...

I would think that you, as a loyal, patriotic, flag-waving, queen-loving Canadien, would want to be in compliance with your CSA. I mean...I mean...Those fine people have fought tooth and nail to prevent lousy, stinking, bottom feeding corporations from incinerating your house in their tireless and perverse endeavors to expand the sacred margin.
Just kidding.
It's your call.

[akabek]

I will remove that fuse. There is already a fuse in circuit.

I am also going to move the green wires back to the indicator lamp. It is a clear look and that less things to fail.

I already bought a replacement power cord. I found the attached diagram to install a 3 prong power cord. I would like to remove the auxiliary outlet and the ground switch as I don't have a need to either.

From the power cord can I run the black wire directly to the fuse and the white wire to one terminal on either the outlet or the ground switch mated to one transformer wire?

[Ten Over]

I will remove that fuse. There is already a fuse in circuit.

I am also going to move the green wires back to the indicator lamp. It is a clear look and that less things to fail.

I already bought a replacement power cord. I found the attached diagram to install a 3 prong power cord. I would like to remove the auxiliary outlet and the ground switch as I don't have a need to either.

From the power cord can I run the black wire directly to the fuse and the white wire to one terminal on either the outlet or the ground switch mated to one transformer wire?

Do not connect the ground wire to a transformer bolt under any circumstances. You have a screw hole right there where you removed the thermal fuse. Use that for the required dedicated ground connection. Make the ground wire longer than the other wires so that it would be the last one to get yanked out when you swing your amp around by its cord.

[akabek]

I will make sure the green ground wire is longer than the other wires and I plan to solder it to the chassis.

[akabek]

I just finished updating the filter caps and I noticed a wire on the side of transformer. Can I cut it off or should I glue it back on the transformer?