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

Guarantee by the manufacturer, 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 for our authorized resellers.
  • 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:

  • When shipping tubes, buyer and seller each pay their own shipment cost.
  • When we have to replace very old tubes by factory new tubes, this is an advantage for the user. For this we must charge something.
  • We replace free of charges within the first three months. We charge 40% of the actual list price from 13 months, until the end of the 5th year.
  • A loose tube base is repaired free of charge during the entire guarantee period.

This is what we do not give guarantee on:

  • Tubes not burned-in by the instructions. (Instructions are in tubes box).
  • Tubes with an issue, which were continued to use after the occurance.
  • 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 Rectifiers, heated with 10V.
  • Failures not caused by Emission Labs, such as:
  • 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 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 intended for extreme surge current, with AC motor control. These can develop leakage unexpected at any time, and should never be used as coupling capacitor for that reason. Any leakage will disappear quickly after, but will also come back at any random moment. This may cause crackling noise, tube sparking, or periodically offset the bias of the tubes, even causing heater damage. Use of such capacitors voids the guarantee always. (Sorry, no exceptions).