Before you buy replacement tubes

Replacing tubes is routine, but a few checks prevent costly mistakes.

Checklist

• Read the tube chart in your amp's manual or on the chassis label and buy the listed type.
• Power tubes are often sold matched. Amps with two or more power tubes typically use a matched set.
• Changing power-tube type may require re-biasing or isn't supported at all. Ask a qualified technician.
• Don't assume a tube that fits is compatible. Same socket doesn't mean same heater voltage or ratings.
• Tube amps hold lethal voltages even when unplugged. Never open the chassis unless you're trained.

Next steps

Look up your tube in the database, then use the replacement finder to see other names for the same type.