Amplifier Blows Fuses
Your amp is blowing fuses:
When the Hi T fuse blows it's usually the time to change output tubes. If you do get new power tubes be sure to get the amp biased.
- Do not replace with a fuse that has a larger amperage rating under any circumstances, higher voltage rating is OK, usually 250 volts.
100 watt amplifiers require 3 A or 4 A. Always try to use SloBlo fuses.
- Look for any broken tubes, they will appear white instead of silver.
- Check for an arced-over tube socket, it will have to replaced before using the amp again.
- On a 100 watt amp, try removing two of the tubes, #'s 1 & 4. Then put them back and try #'s 2 & 3. You can safely run on only 2 tubes.
- Try a different speaker cable and speaker cabinet.
- Check for loose speaker impedance selector if you own a JMP Marshall.
- Check the voltage selector if there is one - set for 120 volts not 110 volts.
- If the fuse doesn't blow immediately then tap on each power tube to weed out any bad ones
- Open the amp and check for anything loose that could be causing a short circuit
- Remove all preamp tubes and replace if necessary