4 ms·

Good practice when literally 'poking around' in an amp is to use a chopstick

by arprocter 11y ago

scarecrowbob 11y ago
Or discharging the filter caps using something other than your hand...
- arprocter 11y ago
  That would also be an option! I know some amps supposedly discharge if you hit the standby and power switches at the same time, but I wouldn't like to trust that
  - dhagz 11y ago
    I've heard you should take a crappy screwdriver, ground one part of the shaft and then touch the capacitor with the head. Something like that.
    - scarecrowbob 11y ago
      I have a (crappy) screwdriver with some bite marks on it from doing that to come 1000V caps in an old panasonic stereo amp. It can work. It's not a good idea, IMO. What I believe is safe enough for me to do... but not so safe that I'd recommend anyone else do it... is to measure the voltage between the high voltage supply and the ground in the amp, and see what you'll be getting if you touch it. If it is more than a volt or so, then connect a 10K resistor between the HV and the ground. That said, if you don't understand why you should do that (or why taking life and death electronics advice from strangers in a comment thread is a bad idea), then you might want to just not get around in there, because you can lose fingers or even die if you don't know what you're doing. :D Go circuit bend a speak and spell or something, and leave tube amps to folks who want to know more whys before touching stuff. :D
beachstartup 11y ago
don't use a korean one!
bsder 11y ago
ONLY PLASTIC ONES! Wood can be conductive depending upon its water content. Even better, don't poke around in an amp unless you have at least a basic knowledge of electronics. The voltages in there are in the range of 500V, and electricity doesn't respond like you're used to at that level (DC switches, for example, need to be much bigger to resist the arcing at those voltages). And, while its cool to see someone hack, the amount of damage EVH did to perfectly good guitars (some of them beyond that) is legendary. Learning even a little about what you are hacking goes a long way.
- arprocter 11y ago
  Interesting WRT water content; but now you mention it, I remember as a kid touching blades of grass on an electric fence and still feeling a shock. My inside-an-amp tinkering only goes as far as pulling 2 of the el84s from a Classic 50 to half the output. It was still stupidly loud for home use though!

Good practice when literally 'poking around' in an amp is to use a chopstick

scarecrowbob 11y ago

Or discharging the filter caps using something other than your hand...

arprocter 11y ago
That would also be an option! I know some amps supposedly discharge if you hit the standby and power switches at the same time, but I wouldn't like to trust that
- dhagz 11y ago
  I've heard you should take a crappy screwdriver, ground one part of the shaft and then touch the capacitor with the head. Something like that.
  - scarecrowbob 11y ago
    I have a (crappy) screwdriver with some bite marks on it from doing that to come 1000V caps in an old panasonic stereo amp. It can work. It's not a good idea, IMO. What I believe is safe enough for me to do... but not so safe that I'd recommend anyone else do it... is to measure the voltage between the high voltage supply and the ground in the amp, and see what you'll be getting if you touch it. If it is more than a volt or so, then connect a 10K resistor between the HV and the ground. That said, if you don't understand why you should do that (or why taking life and death electronics advice from strangers in a comment thread is a bad idea), then you might want to just not get around in there, because you can lose fingers or even die if you don't know what you're doing. :D Go circuit bend a speak and spell or something, and leave tube amps to folks who want to know more whys before touching stuff. :D

beachstartup 11y ago

don't use a korean one!

bsder 11y ago

ONLY PLASTIC ONES! Wood can be conductive depending upon its water content. Even better, don't poke around in an amp unless you have at least a basic knowledge of electronics. The voltages in there are in the range of 500V, and electricity doesn't respond like you're used to at that level (DC switches, for example, need to be much bigger to resist the arcing at those voltages). And, while its cool to see someone hack, the amount of damage EVH did to perfectly good guitars (some of them beyond that) is legendary. Learning even a little about what you are hacking goes a long way.

arprocter 11y ago
Interesting WRT water content; but now you mention it, I remember as a kid touching blades of grass on an electric fence and still feeling a shock. My inside-an-amp tinkering only goes as far as pulling 2 of the el84s from a Classic 50 to half the output. It was still stupidly loud for home use though!