Troubleshooting Tube Amplifiers

Change your tubes

First, have a set of spare tubes on you at all times. Broken tubes are most commonly the problem with tube amps. The tubes are made of glass, and they can break. If see broken glass, your troubleshooting is done. This reason is why so many people have switched to solid state amps. Say you buy a vintage tube amp. It sounds great at the pawn shop. You get it home and hear popping and buzzing. Or you get to your gig and suddenly your amp sounds flat or distorted. These symptoms all could be signs of a blown or cracked tube. New or even vintage tubes run about a $100 a piece so if you can't afford a whole new set, just having one back up tube will be enough to go tube by tube and troubleshoot which tube is broken. When you're at a gig, a spare tube could save your set.

Blown fuse

The next place to check after the tubes is the fuse. Blown fuses are almost as common as broken tubes. It's a good idea to keep a spare fuse with you at all times. The easiest way to blow a fuse is turn your amp on and off repeatedly or to flip multiple switches at the same time. You should never hit more than one switch at a time. If you or a band mate has been enthusiastically flipping switches around the same time your amp goes out, then this may be the first place to look. This can also be caused by exposed wires and rusty soldering. Prevent problems before they start and fix anything that looks loose, corroded, dusty or rusted.

It may not be your amp's fault

Check all wires. Make sure everything is tightly plugged in. Loose connections can make some channels not work, your amp sound flat, cause buzzing and mimic the traits of a blown fuse. If all else fails, try another preamplifier because yours could be broken. Most people don't carry around a spare preamp because they cost as much as an amp. You can, however, troubleshoot with a bass preamp, as long as you keep the bass turned down.