|
|
| Author |
Message |
phazyme
Newbie Alert
Joined: 05 Mar 2007
Posts: 1
|
 Posted: Mon Mar 05, 2007 5:09 pm Post subject: The dangers of electronics: Capacitors. |
 |
|
To anyone who has soldered the way through components, I need some advice on opening the back of a Epiphone Valve Jr., to make some modifications, to eliminate buzzing.
I have soldered and tinkered with guitars, but not amps, and as I understand it the only lethally dangerous part of this, is touching a capacitor, even after the power if off, due to these component's ability to store sometimes huge charges.
So question is:
a) are there any other components that need be not touched due to power issues
b), when one identifies a capacitor, how does one discharge it. I have heard of gator clipping a resistor to one pole of the cap, and then clipping the other end to a metal screw driver with insulated handle and touching the other pole of the capacitor. Is that correct.
Thanks for looking |
|
| Back to top |
|
 |
gavztheouch
Newbie Alert
Joined: 20 Aug 2007
Posts: 1
|
| Posted: Mon Aug 20, 2007 12:21 pm Post subject: |
|
|
| I heard valves from a pre amp or power amp contain enough power to kill if they discharge when you make contact. not sure how true this is though |
|
| Back to top |
|
|
BoutiqueMusic
Big Guppy
Joined: 27 Jul 2007
Posts: 45
Location: Lombard, IL
|
| Posted: Tue Aug 21, 2007 7:24 pm Post subject: |
|
|
| If not properly discharged, your tube amp has lethal voltages present. I am currently on vacation but I will post on Thursday with some details. |
|
| Back to top |
|
|
BoutiqueMusic
Big Guppy
Joined: 27 Jul 2007
Posts: 45
Location: Lombard, IL
|
| Posted: Tue Aug 28, 2007 10:31 am Post subject: |
|
|
Sorry about the delay, but we have had some power problems in the midwest.
For our amplifiers, we use an EL34 power tube.
To discharge OUR amps:
1. Unplug amp from power source.
2. Plug in speaker(s).
3. Clip the test lead firmly to the chassis.
4. Touch the other end of the test lead to the plate / anode terminal of the power tube. For the EL34 it is Pin 3. The speaker will make a scratching noise. This is normal.
5. Attach the test lead to the terminal at pin 3 and leave it there during servicing. Remember to remove this before powering back up or you will have yourself a mess.
There are plenty of data sheets on the internet for tubes so be sure to get the data sheet for your tube before you begin.
If you have any questions, send me an email. |
|
| Back to top |
|
|
nigelwright7557
Tadpole
Joined: 19 May 2008
Posts: 19
Location: Carlisle, Cumbria, England
|
| Posted: Sun Oct 12, 2008 1:22 pm Post subject: |
|
|
| BoutiqueMusic wrote: | Sorry about the delay, but we have had some power problems in the midwest.
For our amplifiers, we use an EL34 power tube.
To discharge OUR amps:
1. Unplug amp from power source.
2. Plug in speaker(s).
3. Clip the test lead firmly to the chassis.
4. Touch the other end of the test lead to the plate / anode terminal of the power tube. For the EL34 it is Pin 3. The speaker will make a scratching noise. This is normal.
5. Attach the test lead to the terminal at pin 3 and leave it there during servicing. Remember to remove this before powering back up or you will have yourself a mess.
There are plenty of data sheets on the internet for tubes so be sure to get the data sheet for your tube before you begin.
If you have any questions, send me an email. |
Its best to discharge the mains power supply capacitors.
Despite shorting out the anode the capacitor can still be charged if you dont do it long enough.
I would put a low value resistor in series with your lead to stop violent discharges which will damage your components and lead. |
|
| Back to top |
|
|
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
