Thread: Re: What Did You Do Today

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Originally Posted by v8nutz

Man you have to be careful inside those old amps. I resoldered a bad resistor on a friend's fender deluxe. I thought I had discharged all the caps first but I had miss the housing on top of the chassis with all the big caps in it. Holy shit that thing shocked me harder than I have ever been shocked when I went to apply the solder. The gun went one way the solder the other across the room. I've been hit by 110v before but this was much more violent. Very stupid mistake and a new respect learned for capacitors.

High tension power supplies in tube amps can have 300 - 500 VDC, the filter capacitors can store the voltage for months (even years)! ALWAYS discharge the caps through a resistor and leave the discharge resistor in place during all the work inside, stand on a rubber mat and work on an insulated (ungrounded) bench. DC voltage has more drive than A/C, it can be very dangerous.

When I change high tension filter capacitors, after discharging the caps with a resistor still attached, I tie a bare jumper wire across each capacitor's leads (+ to -) and leave it there, electrolytic capacitors (even old dried out ones) can have a memory and regain their original charge.

I was not advocating for anyone to look/probe around inside a tube amp (or any electronics/electrical). What I was trying to say, is the old is the same as the new. Obviously I failed in that message..........................................................

I have attached a warning to both posts and will NOT do this again! THANK YOU.

PLEASE DO NOT FOOL AROUND IN TUBE AMPS (OR ANY ELECTRONICS/ELECTRICAL) WITHOUT PROPER KNOWLEDGE/TRAINING!