NEVER NEVER EVEROPEN UP AN AMP NOR STICK YOUR FINGERS OR ANYTHING ELSE INTO THE INTERNAL PARTS OF AN AMPLIFIER OR OTHER ELECTRONICS UNLESS YOU HAVE LEARNED WELL HOW TO DO IT AND CLEARLY UNDERSTAND HOW IT CAN KILL YOU DEADER THAN A FREAKIN' DOOR NAIL. There are voltages inside amplifiers that range from 110 volts to about 5 times the wattage of the amp. If an amp, effects etc plug into the wall, they have at least 110 volts inside; A 100 watt tube-amp has about 500 volts inside; And a 500 watt amp can have 2,500 volts inside. THESE VOLTAGES CAN LAST FOR MANY MONTHS AFTER AN AMP IS UNPLUGGED FROM THE WALL POWER SOURCE ! A NOVICE MUST KNOW HOW TO DISCHARGE THIS VOLTAGE BEFORE TINKERING WITH THE INSIDES OF AN AMP. Some amps even have those high voltages in their special speaker connecting cables !
Guitar and amp expert and guru Dan Torres' website is an excellent resource for Guitar and Amp Technicians, hobbyists and beginners interested in learning about and how to modify guitars and amps for maximum tone and performance. Dan also has a compreshensive product line for guitar and amp modifications.