I brought this home last night...

[MickeyS]

This isn't mine (yet), it's the other guitarists in my band. It blew an HT fuse about 6 month ago, and it's been sitting on the floor at our practice space, while he humps his Diamond head back and forth. This thing needs to be played, so I finally broke down and told him I'd get it up and running for him. The amp was his father's, so technically family owned since new.

 

[80sTone]

This isn't mine (yet), it's the other guitarists in my band. It blew an HT fuse about 6 month ago, and it's been sitting on the floor at our practice space, while he humps his Diamond head back and forth. This thing needs to be played, so I finally broke down and told him I'd get it up and running for him. The amp was his father's, so technically family owned since new.View attachment 138063View attachment 138064View attachment 138065View attachment 138066View attachment 138068

You will love it!

 

[MickeyS]

You will love it!

Oh I know!

 

[scozz]

Sweet!

 

[Rodical]

Let him know you need to order parts that may take a while... I want one...

 

[rolijen]

Sweet! Fuse it up and rock on, brother!

 

[Chris-in-LA]

I wonder if a bad power tube took out that fuse. Are you going to try a new fuse with the power tubes out first?

 

[MickeyS]

I'll probably order up some tubes for it, these are pretty old. That and some fuses and we shall see how it goes.

 

[Central Scrutinizer]

Nice.
Hope you get it.

 

[ThreeChordWonder]

Go through the circuit board with a multimetrr and check all the resistors. Think about a re-cap while you're at it.

Unless you get real particular about replacing the resistors and more significantly the caps with like for like NOS ones it shouldn't be too expensive.

 

[BlueX]

Really nice! That amp deserves good service, and to be played again.

 

[StingRay85]

Cool. I would install all new electrolytics and power tubes before even attempting to fire it up with a new fuse. Cross-check the power tube sockets, because a failed tube can leave a carbon trace on the socket that will conduct. Hopefully the OT wasn't damaged in the process. Make sure to use a LBL when firing the amp up.

 

[MickeyS]

When I get the chassis out I'll post some gut shots....I don't know what has been done to it, but we shall see. I'm debating throwing some EL34s in it, not sure if I'll need to change the bias resistor to get them to bias up correctly, but first things first. It always sounded great at practice, until it went to sleep lol.

 

[Ken Underwood]

Would it not be a good idea to start at the beginning and locate what is causing the fuse to blow, would help to know which fuse has blown first.

You do not just dive in and change things willy nilly, like tubes, resistors and caps.

If this cannot be done then for gods sake get it to a good tech and get it done properly

 

[El Gringo]

Would it not be a good idea to start at the beginning and locate what is causing the fuse to blow, would help to know which fuse has blown first.

You do not just dive in and change things willy nilly, like tubes, resistors and caps.

If this cannot be done then for gods sake get it to a good tech and get it done properly

So true . When I was a kid in the 70's I had my Silverface Twin and it started blowing fuses and like a dummy I kept replacing them and until one day I am playing and I start to smell smoke and go over to the amp and there is blue and orange flame coming from the back of the amp - Blown Transformer . Which really sucked !

 

[El Gringo]

OP, best Wishes on a most fine amp .

 

[MickeyS]

Would it not be a good idea to start at the beginning and locate what is causing the fuse to blow, would help to know which fuse has blown first.

You do not just dive in and change things willy nilly, like tubes, resistors and caps.

If this cannot be done then for gods sake get it to a good tech and get it done properly

Of course that is a good idea and that will be my course of action. Willy nilly isn't my thing lol. Fyi the HT fuse blew. It hasn't been fired up since.

 

[Adrian R]

Of course that is a good idea and that will be my course of action. Willy nilly isn't my thing lol. Fyi the HT fuse blew. It hasn't been fired up since.

If the HT fuse blew then it's most like a bad power tube. Replace tubes, same value fuse...try again.

 

[MickeyS]

If the HT fuse blew then it's most like a bad power tube. Replace tubes, same value fuse...try again.

6550s and 500ma fuses I do not have yet, I'm going to order those. I have plenty of caps and resistors. It's going to get tube sockets cleaned and re- tentioned and a good check out, but I am hoping that is the only issue. We shall see!

 

[anitoli]

Most likely a bad power tube.