Guarantee Conditions

This is what we give guarantee on:

  • The factory test data is guaranteed to repeat when you receive new tubes.
  • All specified parameters, and the good sound of the tube
  • Gas development, the getter flash, or anything else related to bad vacuum.
  • All mechanical issues, like loose contacts, broken off parts, loose tube base, etc.

Standard Guarantee, without registration:

  • 12 months or 2000 hours whatever comes first

Extended guarantee, with online registration.

  • Five years guarantee in case of bad vacuum, mechanical issues or catastrophic defects.
  • 18 months or 2500 hours whatever comes first, on lifetime issues. Please do not confuse this number with expected lifetime.


  • This extended, 5 Yeas program guarantee program is additional to the legal guarantee obligations you receive by the seller of the tubes. It is only valid if purchased via authorized re sellers.
  • The guarantee begins with the date of receival, and is only valid for fully unused tubes. Demo tubes are excluded.
  • The lifetime guarantee is for tubes under typical operating conditions.
  • Online registration must be done within 4 weeks after receival.
  • When a tube is replaced, the original guarantee start date is unchanged.
  • A copy of the original invoice must be supplied upon request.
  • When the failure reason can not be cleared without it, we may require a copy of the amplifier circuit diagram.
  • For each individual case, the final decision to apply the 5 Years enhanced program is finally taken by the factory. This means effectively, the guarantee is voluntary.

Additional costs:

  • We replace at no charges, for a period of 12 months. This period is extended to 18 months if the sale was registered by the first owner, within 4 weeks after receival.
  • When we have to replace tubes after the above period, we are replacing significantly used tubes by factory new tubes. This is an advantage for the user for which we allow the seller to charge something. We recommend for this 40% of the actual list price, until the end of the 5th year, and buyer and seller charge each other no shipment cost.
  • A loose tube base is repaired free of charge during the entire guarantee period.

This is excluded from the guarantee:

  • Tubes not burned-in by the instructions. (Instructions are in tubes box).
  • Tubes with an issue, which were continued to use after the occurrence.
  • Tubes used with electronic circuits for filament heating or plate current control, which we have not approved. Do not buy our tubes, if you disagree with this point. More about it here
  • Tubes with serialized filaments, for instance two 5V heaters in series, heated with 10V.
  • Failures not caused by Emission Labs, such as:
  • Noise with mesh tubes, used as driver, pre-amp or head phone. More about it here
  • Tubes operated above the maximum specifications (No exceptions)
  • Tubes used at too low or too high heater voltage (max +/-5%)
  • Tubes that have been cryogenically treated.
  • Tubes used in stand-by circuits, keeping the tube in stand-by mode for longer than 2 hours. More about it here.
  • Tubes that are used in particular amplifiers, for which we not recommend to use our tubes. More about it here.
  • Tubes showing a spark at switch on or off. This is an amplifier problem, which may be solved. More about it here
  • Use of Paper-in-oil capacitors, as a coupling capacitor to the tube grid. Such capacitors are for motor control, and have a bad reputation for developping sudden leakage. Use of such capacitors voids the guarantee.