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Tube testing service

PLEASE NOTE: Standard testing is included in the price of all the tubes posted on our website. This service is for tubes you send us from your own collection.

All tests will be performed on the laboratory grade Amplitrex AT1000. Custom high voltage test equipment is also available for tube types that exceed 500 Volts. 

Standard test -- $3.00 per tube ($40 minimum order)

Our standard tube testing service includes the following:
  • current draw (mA)
  • transconductance (Gm)
  • gas current (mA)
  • noise/microphonics
  • screening for shorts and leakage

Results are given in percentages of value compared to the expected value for new tubes of that type. The actual mA and Gm readings are also available upon request. Test results for rectifier tubes are given in actual voltage drop readings for each section. These voltage drop numbers are then compared with expected voltage drops based on tube type. 

Premium test -- $10 per tube ($40 minimum order)

Not available for rectifier tubes.

Other services
  • High voltage testing -- 500+ Volts ($12 per tube)
  • Repair broken guide pins ($10 per tube)
  • Glue loose bases ($5 per tube)
  • Straighten pins -- 9-pin & 7-pin tubes only ($2 per tube)
  • De-gas power tubes ($12 per tube)
  • New white boxes (50 cents each for 9-pin size, 6SN7/6V6 size, EL34/6L6 size boxes; 75 cents each for 6550/KT88 size and 2A3/5U4G size boxes)

Please pack your tubes securely and use USPS Priority mail to send them to this address (UPS and FedEx do not ship to our secure PO. If you cannot use USPS, please contact us for an alternative address):

TC Tubes, LLC

PO Box 6511
St. Paul, MN 55106


Follow the link below to contact us for an estimate. With our current back-log, turn around time is 2-3 weeks. Once the testing is complete we will contact you with preliminary results and send you an invoice for the total (we accept payment via Paypal, credit card, or check).

Request an estimate
TC Tubes specializes in precision testing and matching of vintage and new production vacuum tubes for guitar & bass players, audiophiles, and DIY tube audio enthusiasts. Our website features secure payment options and fast, convenient shipping around the world.

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