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Discharging a tube amp?

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pitbull3825
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Discharging a tube amp?

#262375

Post by pitbull3825 »

I now own two Palomar 300a amps. One has no tubes in it I have them and I have to wire up the transformer. But I do not know how to make sure I'm not gonna get ZAPPED I have herd horror stories please help?????
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When we fall asleep, we commit no sin When we commit no sin, we go to heaven. So, let's all get drunk and go to heaven!"

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Re: Discharging a tube amp?

#262376

Post by Night Crawler »

Use a Chicken Stick from the HV point to ground to Discharge the Filter Caps.
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Re: Discharging a tube amp?

#262377

Post by pitbull3825 »

That is all Chinese to me. Laymen terms please.
Honorable discharge 8 years U.S. Army 63S E-5
Locally you will listen to what I say!!!

"When we drink, we get drunk. When we get drunk, we fall asleep.


When we fall asleep, we commit no sin When we commit no sin, we go to heaven. So, let's all get drunk and go to heaven!"

George Bernard Shaw
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'Doc

Re: Discharging a tube amp?

#262416

Post by 'Doc »

Basically means an insulated handle on a shorting device. One end is connected to chassis ground, the other end you touch to the terminals of the capacitors, or the plate caps of the tubes. A common screw driver is a very common (and NOT smart) 'chicken-stick'. Touch shaft to chassis, tip to plate cap on tube. Almost a guarantied way of startling the sh_ _ out of you! Can also take a 'bite' out of that screw driver tip. Not a bad idea to do that shorting more than once, you know?
If you ever get 'bit' doing this sort of thingy you'll remember it for a very long time, IF you're very lucky...
- 'Doc
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Re: Discharging a tube amp?

#262433

Post by Foxhunter »

Part of the danger or risk depends on the value of the capacitor(s) used. There are some large amplifiers that use very large "canister" capacitors (sometimes several in "a bank") and these kind especially really are high voltage capacitors.

You'd better watch it working on the big boys. Those discharge tools, aside from being called "chicken sticks"----are also sometimes called "Jesus Sticks". If you don't safely and properly discharge your capacitors and use them correctly----you'll be going off "to meet Jesus".

:monkey:


Foxhunter 351 NJ



Here's a short Youtube video on high voltage capacitors for your viewing fun.
I imagine an apple has about the same density and moisture content as a human finger.

[youtube][/youtube]
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Re: Discharging a tube amp?

#262452

Post by KOA4705 »

pitbull3825 wrote:I now own two Palomar 300a amps. One has no tubes in it I have them and I have to wire up the transformer. But I do not know how to make sure I'm not gonna get ZAPPED I have herd horror stories please help?????
E = 1/2 * U^2 * C

Where
E = Energy in capacitor in joules
U = Voltage in capacitor in volts
C = Capacitor capacitance in farads

intuitively (.5) voltage C squared x Capacitance

Joe
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Re: Discharging a tube amp?

#262527

Post by Night Crawler »

pitbull3825 wrote:That is all Chinese to me. Laymen terms please.
Here's an article that shows the precautions to take when working on an amp that uses high voltage
and how to use a chicken stick.
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Re: Discharging a tube amp?

#262545

Post by pitbull3825 »

Man now I don't wanna do it at all. Ok who's gonna come over and do it for me? LOL No problem I think I have a very very good understanding on it now.
Honorable discharge 8 years U.S. Army 63S E-5
Locally you will listen to what I say!!!

"When we drink, we get drunk. When we get drunk, we fall asleep.


When we fall asleep, we commit no sin When we commit no sin, we go to heaven. So, let's all get drunk and go to heaven!"

George Bernard Shaw
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Re: Discharging a tube amp?

#262551

Post by KOA4705 »

Hello All,
E = 1/2 * U^2 * C

Where
E = Energy in capacitor in joules
U = Voltage in capacitor in volts
C = Capacitor capacitance in farads

E= .5 x U squared x C

Joe
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Re: Discharging a tube amp?

#262555

Post by KOA4705 »

Just a quick note:
E = 1/2 * U^2 * C

Where
E = Energy in capacitor in joules
U = Voltage in capacitor in volts
C = Capacitor capacitance in farads
Joe
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Re: Discharging a tube amp?

#262653

Post by Night Crawler »

pitbull3825 wrote:Man now I don't wanna do it at all. Ok who's gonna come over and do it for me? LOL No problem I think I have a very very good understanding on it now.
Don't worry you'll be alright if your careful.
I got hit with 800 volts once lucky it was low current, that will wake you up better then a cup of coffee :biggrin:
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Evil_Wind

Re: Discharging a tube amp?

#273748

Post by Evil_Wind »

Holy OUCH ! :confused:
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