How to Repair Tube Amps
Guitar players prefer tube amplifiers over solid-state amplifiers because of the warm and rich tone they produce. Solid-state amps are more durable and require less maintenance than tube amplifiers but the sound quality pales in comparison to a well-functioning tube amp. Tube amps, on the other hand, need regular routine maintenance. The general rule of thumb is that you should change your tubes once a year if you are using your amp on a regular basis. Tubes are fragile and unpredictable and may unexpectedly go bad. In addition to bad tubes, other parts of the amplifier may need to be repaired from time to time as well.
Other People Are Reading
Things You'll Need
- Spare tubes
- Spare fuses
- Contact cleaner
- WD-40
- Brush
- Cloth
- Phillips screwdriver
- Pliers
Instructions
-
-
1
Take extra fuses and tubes to the performance. If a tube amp fails to work at a gig it is important to be prepared. Always carry spare fuses and tubes in your gig bag. All tube amplifiers are wired for specific tubes and fuses. Using the wrong tube or fuse runs the risk of damaging the amplifier. If the amp suddenly loses power, it has probably blown a fuse. The fuse on guitar amplifiers is usually on the back of the amp. Look for a black cylinder-shaped fuse cap. Twist the cap clockwise and pull it up. Take the fuse out and replace it with a new one.
-
2
Diagnose tube problems. Weak or bad tubes are recognizable by a few different symptoms. Weak power and poor sound quality are both signs of weak power tubes. Bad pre-amp tubes emit a high-pitched squealing sound. Examine the color of the tubes when the amplifier is turned on. Healthy tubes should glow with a medium-intensity orange color. A blue glow indicates a weak tube. A bright red glow indicates that the tube is overheating. Turn the amplifier off and let the tubes cool down. Remove the tubes and examine them for cracks or discoloration.
-
-
3
Replace bad tubes. Make sure you use the correct tube. Remove the bad tube. Spray contact cleaner into the tube socket and clean the socket with a small cloth or brush to remove dirt and debris. Spray a bit of WD-40 into the socket to keep it lubricated. Align the notch on the tube with the notch in the tube socket and gently push the tube into place.
-
4
Clean the amplifier knobs and pots. Dirt and debris also builds up in the guitar knobs and pots. Dirty knobs and pots produce scratchy or crackling sound when you turn them. Spray the knobs and pots with contact cleaner. Rotate the knobs several times to work the contact cleaner into the pots.
-
5
Tighten all the nuts and bolts on the amplifier. Amplifiers experience lots of wear and tear from sound vibrations and from being carried and moved around. This eventually causes various nuts and bolts on the amplifier to become loose. The result is rattles, buzzing, and humming noises. Tighten all the nuts and bolts with a Phillips screwdriver and pliers. Pay particular attention to the speakers and the input jack.
-
6
Make an annual appointment to have your amplifiers professionally serviced. A annual tune-up is the best way to keep your tube amp in good shape. Tube amplifiers contain dangerous levels of high voltage. Have a professional amp tech check the capacitors
and resistors. When you replace all your tubes it is also necessary to have the tubes biased.
-
1
