#1
I'm really starting to get beyond fed up and am ready to hurl my amp out the window.

I've posted about this several times before and i'm hoping this thread will be in-depth enough for me to get some solid answers to resolve it.

I have a special 6 ultra (which i'm fairly happy with) aside from an awful noise issue. The noise sounds almost like a blowtorch mixed in with static and feedback. This is not normal feedback at high volumes. Its so loud that you can hardly hear the guitar through the noise. Noise gates/suppressors have not even remotely helped.

The noise is present even when there is no cable connected to any of the outputs. So far, that means that the guitars, pedals, pickups have been ruled out as being the problem. I have tried covering the tubes with tin foil (all I have on hand) to see if it is a problem with interference with the tubes and this hasn't worked either.

Some times, the noise will stop and just the normal feedback will be audible, but as soon as I play a note, the noise comes back.

I'm really beyond fed up with this issue. It's been going on for over a year and it is getting to the point where i'm ready to give up entirely. Can anybody please tell me how to either resolve this issue or what the source of the problem is? All I want is a normal amp that will not create so much noise that it isn't even worth turning on to play.

I'd like to at least be able to take it to guitar center or somewhere knowing what is wrong with it so they don't charge me an absurd amount to fix it. Is this an issue with the speaker? The jacks? some sort of wiring issue? Can I fix it myself?

I'm on a budget but would like to fix it and get rid of it so i can get a 6505+
#2
Sounds like a bad filter cap.

The problem here is that it's impossible to diagnose for certain over the internet, and if you just start replacing stuff like filter caps hoping that's the problem you're going to start incurring serious costs.

I'd at least start by pulling the board and seeing if any of the joints, especially near the filter caps, are burned or have very little solder on them. If in doubt, re-flow the contact. If that doesn't work, it might be new filter cap time. Please don't mess with your amp unless you're familiar with how to safely work on it, those filter caps will store enough charge to kill you for a long time after you've turned the amp off.
#3
Sounds like it could be a tube problem. I had a microphonic pre amp tube in my amp and it made a loud high pitched sound when turned up a bit louder. Have you tried changing your tubes?
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#4
Quote by MaggaraMarine
Sounds like it could be a tube problem. I had a microphonic pre amp tube in my amp and it made a loud high pitched sound when turned up a bit louder. Have you tried changing your tubes?


I changed the tubes last year I think and have a new set of JJ's (6v6 and 2 12ax7's). there is maybe 100-150 hours on them.

If i take this to somewhere like guitar center, what kind of cost would be associated if i just dropped it off and told them to go through the whole thing and fix whatever problem there is?

And I have about zero electronics experience so I'd rather leave all that stuff to people who have a clue so I won't be messing with the board. I'll go about as far as swapping a speaker or a jack and thats about it.
#5
Do you have any other 12AX7's on hand? Try swapping them out one at a time and see if the noise disappears.
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#6
Could be one or two issues among a lot of things. But have you tried using this amp at a different building/house? I would try that first, not just a different apartment in the same building but an entire different building altogether. Unless you've got spare tubes at hand & replacing them doesn't have much effect on the noise then it's best to take it to a tech. Labor charges vary so it depends on what's wrong with it & if any parts need to be changed then that will add up as well.
#7
Quote by Roc8995
Sounds like a bad filter cap.

The problem here is that it's impossible to diagnose for certain over the internet, and if you just start replacing stuff like filter caps hoping that's the problem you're going to start incurring serious costs.

I'd at least start by pulling the board and seeing if any of the joints, especially near the filter caps, are burned or have very little solder on them. If in doubt, re-flow the contact. If that doesn't work, it might be new filter cap time. Please don't mess with your amp unless you're familiar with how to safely work on it, those filter caps will store enough charge to kill you for a long time after you've turned the amp off.


It does sound like a cap. To expand on what he said look at your electrolytic caps, the round aluminum ones, and see if any of the vents have popped. Sometimes when they go bad you can physically see it. Sometimes you can't and it would get very expensive to just guess and start replacing them.

It might even be a coupling cap, and in that case there wouldn't be a visual indicator.

Sometimes you can find them by pulling the chassis out and running the amp upside down and tapping on the capacitors with a non conductive stick like a chopstick. Lethal voltages are present and you should not attempt it. Even if you do find a bad capacitor are you able to replace it? Do you have a soldering iron?


Now how long has this problem been going on? You can get bad tubes right out of the box... When did this problem start in relation to your tube replacements?
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#8
Quote by R45VT
It does sound like a cap. To expand on what he said look at your electrolytic caps, the round aluminum ones, and see if any of the vents have popped. Sometimes when they go bad you can physically see it. Sometimes you can't and it would get very expensive to just guess and start replacing them.

It might even be a coupling cap, and in that case there wouldn't be a visual indicator.

Sometimes you can find them by pulling the chassis out and running the amp upside down and tapping on the capacitors with a non conductive stick like a chopstick. Lethal voltages are present and you should not attempt it. Even if you do find a bad capacitor are you able to replace it? Do you have a soldering iron?


Now how long has this problem been going on? You can get bad tubes right out of the box... When did this problem start in relation to your tube replacements?


if i remember correctly the issue started prior to changing the tubes and thats why i changed them in the first place. My dad suggested it may be dirty power because he mentioned having problems with phones in the past due to it.

What are my options for power conditioners?
#9
I doubt that's its unless a power spike caused a problem.

Cheapest thing to do is take it to a friends house and see if the noise continues there. If it does it's inside the amp.
Quote by DeathByDestroyr
See, it's important that people clarify when they say "metal", because I pretty much always assume they are a Cannibal Corpse fanboi.