Bluesbreaker innards, I'm still alive and here are PICS!

[Guest]

Okay! So I went inside my blusbreaker to take a look. First time I've opened a tubeamp so I was a little nervous, I proceeded very carefully and I'm still alive

One of the preamp tubes is the tremolo tube right, which one?

I don't know alot about how things should look so I took some pictures and want the Amp Gurus here on the forum to give me a hand of if everything is looks okay.

Problems with my amp:

1. Tremolo buzz. Tremolo isn't usable on lower volumes as the buzz increases when rasing the intensity, and those of you who know the marshall tremolo isn't really powerful so the intensity needs to be set quite high. The buzz increases when rasing intensity even if I've turned the tremolo off. This pot seems scratchy.

2. The prescence knob is also scratchy. And it amplifies the buzz from the intensity pot when it's raised.

3. Sometimes when turning to standby the amp pops. Don't now if this is bad or not. But it doesn't happen everytime a turn to standby, and I haven't found a pattern in it either.
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For future projects...Where do one adjust the bias?

The intensity pot was a little loose and seemed to touch the screw that thightens the back of the cabinet to the chassi, so I turned it out of the way for the screw and tightened it up.

There's a height difference on the standby and power switch. I don't now if this has effect on the popping problem or if the switch has been changed or something.

Here's a shot of the Speed, Intensity and Presence knobs from the inside. Does anything look suspect? Can I use regular "Contact Spray" and spray the pots with that from the outside to maybe solve the scratchy pots?

Thanks for your input!

 

[Rich_S]

Re: Bluesbreaker innards, I'm still alive and here are PICS!

Contact spray - yes. I just get mine fro Radio Shack; I assume you have aready source in Finland, too. Just give each pot a squirt, then twist the knob back and forth a few times. It should clean up your scratchy pot problems, and maybe your tremolo buzz.

I'm guessing the trem tube is the 3rd from the left in the top photo, but you'd need to check against the schematic to confirm. The one on the other side of the output tubes is probably the PI.

The switch-height thing is not a problem. If you look at the front, more of the standby switch's threads are exposed. At some point, the jam nut between the switch body and the inside chassis loosened, and somebody took up the slack by tightening the outside nut, rather than opening up the chassis. Just screw both nuts back toward the switch body until the standby switch looks like the power switch. BTW, this is not causing your standby pop problem.

 

[Scott_F]

Re: Bluesbreaker innards, I'm still alive and here are PICS!

Run a .047 cap from the standby switch leg to a ground. I always choose the leg that goes directly to the rectifier power, not the leg that runs to the choke/OT red wire.

 

[Guest]

Re: Bluesbreaker innards, I'm still alive and here are PICS!

Thanks to both of you Scott_F and Rich_S! I'm gonna get me some Contact spray!

A 0.47 cap between the leg that goes to the rectifier and a ground. I'll keep that in mind.

Educate me a little more on my amp

How about the Bias, where's to adjust that?

And where are the "dangerous" parts in my amp, other than the places that capacitors and tube sockets connects to the chassi?

Eg. Can I safely loosen standby swtich and pot nuts inside the chassis and tighten them from the outside to adjust the height, without any risk for shocks? And the same question for soldering a 0.47 cap from switch to ground?

 

[Scott_F]

Re: Bluesbreaker innards, I'm still alive and here are PICS!

You need to read what I said more closely. I said .047 uf , not .47 uf.

Those big blue cans, as people have told you before, are the most dangerous spots. Then follow the wires from teh blue cans and see where they attach to the main board. It's all dangerous in there if you don't have a clue.

Take it to a tech and have them show you how to discharge the caps

 

[PUCKBOY99]

Re: Bluesbreaker innards, I'm still alive and here are PICS!

.......and the trem tube is the one to the right of the power tubes.

When looking at it from the rear, from left to right:

V1/V2(P.I.)/V3...Power Tubes...Trem Tube...Rectifier Tube

I had one of these (a 1998) & the trem was pretty useless...do you have a footswitch for it? If not, stick a 1/4" cable in the input...nothing attached to the other end. It seemed to quiet mine down a bit.