Amp noise

Pure_Brew

Pure_Brew

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What causes the background hiss and noise in amplifiers? What causes it to increase with age?
 
Skratch

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I've had to replace old carbon composition resistors that go out of tolerance with metal film and the hiss goes away
 
Elite-ist

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The white noise can help you get to sleep if you turn the volume half-way, Joe. Just trying to put a positive spin on the issue.

Nando.
 
Pure_Brew

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Maybe I should grab an online degree as an electronics tech. Might be useful when I get older. Almost pulled the trigger a few years ago with DeVry.
 
Pure_Brew

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Elite-ist said:
The white noise can help you get to sleep if you turn the volume half-way, Joe. Just trying to put a positive spin on the issue.

Nando.
Click to expand...
Lmao!

At least my speaker sensitivity is sort of low so I cant hear it normally.
 
orange

orange

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Elite-ist said:
The white noise can help you get to sleep if you turn the volume half-way, Joe. Just trying to put a positive spin on the issue.

Nando.
Click to expand...
Turn it up higher and you can still pretend Carson's off.
 
Pure_Brew

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Wow last night, the power transformer in my tube amp started to buzz horribly!
I tried to isolate it unplugging and bypassing everything - no difference.
Then I plugged in the Pioneer. OMG the same buzz but now through the speakers!

Then, suddenly, it went away...

I think it's time to have an electrician look at this place. Or is there an independant test I can do?
 
laatsch55

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Sounds like a grounding issue, or resistance building up in some connections. If it's old, check where the ground wire comes in from the pole. It will be connected to a water pipe or a copper plated steel ground rod. If it's a newer place, the ground and neutral circuits will be bonded to a strip where the ground from the pole is brought into the house and attached at the same place. Check these connections, if they are good it could be an appliance or some othger electrical device feeding back in the AC line. To check that, make the noise audible on the tune box and unplug each device, verify that unplugguing it did or did not affect it.
 
jbeckva

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laatsch55 said:
Sounds like a grounding issue, or resistance building up in some connections. If it's old, check where the ground wire comes in from the pole. It will be connected to a water pipe or a copper plated steel ground rod. If it's a newer place, the ground and neutral circuits will be bonded to a strip where the ground from the pole is brought into the house and attached at the same place. Check these connections, if they are good it could be an appliance or some othger electrical device feeding back in the AC line. To check that, make the noise audible on the tune box and unplug each device, verify that unplugguing it did or did not affect it.
Click to expand...
That is odd stuff, but hmmm... I remember WAAAAY back in the days of going to VoTech electronics how we had a tube "rejuvenator" thing. One of it's functions was to burn out "shorts" or something across the grids.

Hmm.. or was that just for TV electron tubes? (No, I didn't learn much in those days... "BUZZ" wasn't something that meant a "sound" to me back then... :rr:)
 
Pure_Brew

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laatsch55 said:
Sounds like a grounding issue, or resistance building up in some connections. If it's old, check where the ground wire comes in from the pole. It will be connected to a water pipe or a copper plated steel ground rod. If it's a newer place, the ground and neutral circuits will be bonded to a strip where the ground from the pole is brought into the house and attached at the same place. Check these connections, if they are good it could be an appliance or some othger electrical device feeding back in the AC line. To check that, make the noise audible on the tune box and unplug each device, verify that unplugguing it did or did not affect it.
Click to expand...
Would it help to take a look at the AC with a 'scope?
 
laatsch55

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Yes, itb would tell you if you have somethoing other that 60 Hz running around, but DO NOT hook the scope directly to the AC. Go through an isolation transformer.
 
kevin

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Unhook your cable out of the wall and see if that makes a difference.... I went through that stuff for weeks.... If I had any hair I would have pulled it out !
 
Pure_Brew

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Yeah I've fixed a few problems for customers who had CATV ground issues. Very common. Low voltage techs can run without individual licenses in most states. It shows.
 
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