How To Fix A Guitar Amp

Want to know how to fix a guitar amp? There are many things to check and repair in a guitar amp. Guitar amps have new technology in them for sound effects, but the basics of guitar amps have stayed pretty much the same over the years. Before we get started you will want to unplug everything and turn the amp off.

To fix a guitar amp, you will need:

  • A screwdriver
  • A multi-meter
  • An ohm meter
  1. It is important that the power cable is grounded properly and that it is not loose. If you are getting a buzzing noise from your guitar amp, most likely it isn't grounded properly. To check the ground you will want to locate where the power cord is and follow it inside the amp. Once you have located the grounding wire you will want to make sure the connection is not loose and that the washer keeping it in place is tight enough. If the wire and connector seem loose you will want to re-solder the connector to the wire.
  2. Check the amp tubes and bias the tubes. Before checking the amp tubes make sure you have full access to them. If possible, remove the inner workings out of the case and put it on a solid table. You will need a biasing master meter that will help you bias the guitar amp tubes. To remove the amp tubes, turn them in a circular motion and then pull them up and out of the socket. Next you will want to connect the master meter to the socket connections of the amp tube. Put the amp tube back in using the same circular motion as used to remove the amp tube. Now turn on the amp for 30 seconds. After you turn it off, turn on the master meter and you will get the bias reading. To set the bias, there is an adjustment screw that you can turn either to the right or left using a screwdriver. One way you will make the number go up and the other way will make the number go down. You will want to make sure that all the amp tubes are within 0.10 bias meter of each other.
  3. Check the capacitor. Before touching or coming close to the capacitor you will want to discharge it! It holds a charge dangerous enough to kill. So make sure you have it discharged. If you are not sure how to do this, have a experienced technician do this for you. For the capacitor we will use an ohm meter to check its output. There should be a label on the capacitor to say how much it outputs. Make sure it is close to what it should be.
  4. Check the speaker. If the speaker sounds fuzzy or dirty, maybe a wire connection is loose. If so, just re-solder the wire on the speaker and this should take care of the problem. You may also want to check the integrity of the speaker to make sure nothing is broken or missing.
  5. Turn it on. Now for the final step you will want to put everything back together and turn your guitar amp back on. It should be working better now.