my 73 silverface DR just died.

[Skiroy]

Hey guys,my amp just stopped making sound. You know when you turn the amp on you here the noise floor out of the speakers? Yeah it doesnt even do that. I was playing for 3 hours with a bunch of different pedals doing a huge shooutout.

I know its not the preamp tubes and from what I was told the amp will still work even with the reverb, recovery reverb and tremolo tubes taken out so it cant be them. I also swapped the phase inverter 12ax7 tube with no luck. The fuse is not blown and the main transformer is getting power.

So it has 2 power tubes. is it one for each channel or are they in series? Im trying to rule them out. I tried measuring voltage on some resistor and caps in the preamp circuit and there is nothing. The power amp tubes come after the preamp section right the the problem is before the preamp sections and it affecting both.

Is it neccessary to pull the tubes to test voltages of the transformers? And how do I know what voltages to look for?

And help here? Could it be the big rectifier tube?

If one power amp is out will it cause this or is each power tube for each channel?

[52 Bill]

Does the pilot lamp light up? Are all of the tube filaments lighting up (the small orange glowing lights inside the glass)?

My first guess would be the rectifier tube. The one on the far left side. If it dies, it would turn off all of the high voltage to the amp, just like if the standby switch was still off.

The two power tubes are for each half of the signal not one for each channel. If one died, the signal would be weaker and distorted, but it would still make sound.

[acorkos]

you might have killed your speaker. try another one

[Chuck H]

+1
Try a different speaker. Try a different rectifier tube. Both long lived items... That don't last forever.

NO sound with the amp on is indicative of no current through the OT. So it is most likely a power supply or power amp failure.

How did it quit? Did it just go silent during use? Did you take it home and the next time you turned it on it didn't work? Did it make any unusual noise, smells or smoke at any time?

Has the amp been regularly serviced? How old are the power tubes? How old are the power supply filter capacitors?

[mort]

Last time this happened to me it was an open speaker. Time before that was a fried recifier tube.

[Skiroy]

Yeah guys all the tubes were sent off and tested good. But it just went silent while playing. And it was the speaker. Thats really weird I always had a speaker distort before it died. Never just go silent. This sucks because it was a vintage P12Q I just bought. I guess I pushed it too hard. I hope the weber can hold its own better. I also have a vintage c12n I want to try out in it.

Thankx again guys. And the guy I bought it from said it was serviced when it was black face modded. It does appear to have some new caps and resistors in it. All the tubes do light up.

It must of been all the crazy abuse I put it through with the pedals and changing guitars without turning it down. Too many clicks and pops I was trying to cheat and do the immense shooutout faster.

[Chuck H]

I've read in many places that the old Jensens were assembled with hide glue. Hide glue becomes more and more brittle the older it gets. Not the best thing for a speaker. Lots of guys burn up their old Jensens. The best thing you can do with a vintage speaker in a collectible amp is remove it and put it in a box. Stick a speaker in the amp you can use and save the original in working conditionin case you ever want to sell the amp.

[Enzo]

A speaker is a coil of wire. It can burn out like a light bulb - poof, gone. It can also overheat and cause voice coil warp and distortion. The voice coil wires tend to stay put, but the glue that holds them to the form can fail, leaving loose wires to rub or snag or tear out. ANd not just the voice coil. The flexible links from the terminals over to the cone are called tinsel wire, and that can break from flexing.

Like anything else, there is no ONE way things fail.

[Jazz P Bass]

Like anything else, there is no ONE way things fail.

Enzoism #6.

[Skiroy]

My speaker jack has a white and black/brownish wire. Which is positive and which is negative and is polarity a big issue when hooking up speakers to these old amps?

[Jazz P Bass]

There is no polarity per se for one speaker.
After all, it is an AC signal.
It will be hard to meter out which one is which because of the output transformer.
But if you look at the rear of the jack, you will probably be able to tell which one is grounded.
(my bet is the black wire)

[mort]

This sucks because it was a vintage P12Q I just bought. I guess I pushed it too hard. I hope the weber can hold its own better. I also have a vintage c12n I want to try out in it.

I bought a brown princeton, all original, from a buddy of mine a while back. Played it for a while at his house, just guitar through the amp, and it sounded great so I gave him the cash and split. When I got home I turned it on and played with the volume at 4 [for about 5 minutes] and then it just went silent. Speaker gone. Can happen at any time. I told the guy about it later on and he tried to compensate me for it but I refused. No telling when an old speaker will bite the dust, not his fault.