I posted over in the forum issues forum regarding a possible safety sticky here in the Shock Bros forum. I figure it would be a good move, and we could all just link or refer to it when it's warranted, instead of typing out countless warnings about the dangers of sticking your tongue on a charged up filter capacitor. Paul's on board, but someone needs to write something. I thought maybe a team effort might be in order. I figure we need a paragraph on the overall danger, and then one or more suggestions on how to safely discharge filter caps. We could compile them here, and then someone can repost the result for a cleaner sticky. Make sense? I can't tell. It's too early in the morning for me - I've got a road trip for work, and I'm waiting for my comrades to show up. How's about this for a start: "WARNING Vacuum tube (valve) amplifiers contain potentially lethal electrical charges, even when powered down and unplugged. Do not open an amplifier if you are not completely versed in the necessary safety measures. This is a hobby for some, and a profession for others, but like many others it involves a certain amount of risk that can be minimized by following a set of best practices. SAFETY CONSIDERATIONS First and foremost, never perform any repairs or modifications to the circuit of any amplifier when it is plugged in, whether it is powered on or not. Secondly, the filter capacitors in tube amplifiers are of significant concern. They are typically the largest components inside the amplifier, and in some cases are located outside of the main chassis. Capacitors by their nature maintain a charge after current has stopped flowing to them. This charge can be extremely hazardous. To work inside of a tube amplifier safely, the capacitors must be discharged." ...and then I figured we could follow up with alternate cap discharge methods and other safety tips. I'm loathe to type out the "screwdriver method" myself, just because I find it somewhat clumsy, and generally don't think it's a good idea. I personally use a 150 ohm 10w power resistor in the middle of a length of wire with an alligator clip on one end, and a probe on the other. All wire connections are covered by heatshrink. A few seconds on each cap and they read clear. One should note that the filter caps in some amps may not be visible - the cap for the preamp supply on some Marshalls is under the board, and of course the caps in some Fenders are mounted to the underside of the chassis. In this case, I touch both ends of the power supply resistors on the board until they measure safe as well. Keeping one hand in your pocket during this procedure can be a good idea too I suppose, but I'm typically holding my multimeter probe with my free hand, ready to measure things just in case my resistor shorted and I didn't know it. Either way, using both hands on a live or charged amp is a good way to pass a nasty shock right through your heart. Anyone care to add anything? ...By the way, there used to be a great little module (2 minute) show on the public radio station that I work for that covered the etymology of words that people probably think they're using correctly. Did you know that the word "electrocuted" necessarily indicates that the victim died from the experience? Otherwise it's just being shocked. The show was funded by Merriam-Webster, who just had to pull its support because of financial difficulties. And so it goes. Okay, yes, I'm bored.