How To Fix Blown Guitar Amplifiers

Guitar amps store power, so use caution.

Has the tone in your amplifier become weak or nonexistent? Does one tube in your amp no longer glow when the amplifier is on? If so, you've got a blown amplifier or more accurately, a blown vacuum tube inside your amplifier. Tube amps have a great tone, but the tubes must be replaced when they get old or weak or stop working altogether. Many people take their amplifiers to service technicians. But replacing tubes does not require any specialized tools, so someone with little knowledge of how tube amplifiers work can do the job.

Things You'll Need

• Screwdriver
• Replacement tube set
• Gloves

Instructions

1. Unplug the guitar amplifier from its power source. This step is often overlooked, but an amplifier stores power. Leaving it plugged in while you service it can give you an electrical shock and seriously damage the amplifier.

2. Remove the metal grate panel from the rear of the amplifier by taking off all of the screws that hold it to the amplifier casing. This will give access to the tubes that power the amplifier. Not all tube amps have rear covers. If you have an open-back amp that allows access to the tubes, skip this step.

3. Pull up slowly on the tubes to remove them from the amplifier. They are not screwed into place or held in with brackets, but rather have pins protruding from the bottom. These pins are pressed into the tube plugs and can require slight force to pull out. Tubes can crack because they are made of glass. Pulling straight up will prevent the glass from breaking.

4. Press the replacement tubes into the amplifier by matching up the pins with the holes in the tube plugs.

5. Screw the metal grate cover back on if your amp has one.

Tips & Warnings

• Every guitar amp uses a specific size tube among a wide range available. Unless you are trained in changing the size or value of a tube amp, stick to direct replacement tubes for your amplifier. A competent vacuum tube retailer can help you determine which tube is best for your amplifier.

• Keep tubes clean when installing them to prolong their life. Use a pair of work gloves to prevent your hands from getting oils on the tubes.

References

• AthensMusician.net: Tube Amps
• VacuumTube.com: Guitar Tubes