By
eHow Arts & Entertainment Editor
Difficulty: Moderately Challenging
Step1
Make sure you have the right parts. Different makes and different years are not usually compatible. Don't take a chance, take a look at the tube standards usually printed on the interior of your amp and get what you need.
Step2
Get inside the amp cover. Most of the tube amps have a back cover that you can easily unscrew or otherwise remove.
Step3
Locate your pre-amp tubes. The pre-amp tubes are generally near contact switches. They are smaller than other tubes in the amplifier.
Step4
Unscrew any tube covers. Some of the pre-amp tubes on amp models are covered by metal shields that can be unscrewed to access the tube itself.
Step5
Remove the old tube by gently wiggling it until the various small prongs come away from their housings.
Step6
Notice where gaps in the prong structures are to make sure you insert the new pre-amp tube in the same direction as you removed the old one.
Step7
Insert the new tube, cover it up, and replace the amp hood.