Tubes that we sell go thorough the following process:

• Tubes will be tested and marked in µmhos values using my computerized Western Electric KS-15874-L2 lab grade tube tester.  While I have owned an Amplitrex AT-1000, Hickok 539C?s, TV-7?s, etc., I find this lab grade computerized tester to be extremely accurate and capable of testing a very wide range of tubes at actual working voltages.  I will test for both µmhos value as well as shorts, gas leaks, and noise.

• If needed, Tube Pins will be cleaned using a proprietary method we have developed over the years.  This is a major cause of noise in vintage tubes.  They build up oxidation and a patina over time and need to be cleaned properly to ensure proper connectivity both when inserted and over time.

• Matched tubes (dual triode, etc.) will be compared with their µmhos values.

• Boxed in either their original boxes or white boxes.  When possible, tubes will be labeled with removable stickers indicating their µmhos values.  When not practical to put on the tube, I will insert labeling in or on the box.

• Premium tubes listed as 'low noise' will be tested for noise using a custom audio setup we have built in an actual amplifier circuit with very high gain.  Typically this would apply to a Hi-Fi setup.  If you need a tube we have listed tested for microphonics (physical movement noise) for guitar amplifier or similar use, please let us know, we can do this upon special request.

• Packed and shipped professionally.

Combined Shipping: Yes, we offer combined shipping.  If buying at full price, just add more than one tube via "add to cart" functionality and eBay will automatically calculate the combined price.  If you want to "make an offer" on several tubes, just offer $5 less on the 2nd, 3rd, etc. to be considered free shipping.

Limited Guarantee:  We guarantee our tubes for 30 days.  All of our tubes are guaranteed to match the specs we rate them at and not to arrive DOA.  We can?t guarantee tubes over a period of time due to all the various use cases and scenarios they get used in.

Not Happy With Your Tube?:  Occasionally, we have seen perfectly good tubes that we have tested not endure the stress of being tossed around during shipping and either die or pick up characteristics that were not present when we tested them.  If you encounter this, please contact us.  We will either replace the tube asap or refund your money.  We try to make this a hassle free process but sometimes things happen, its how we deal with them that matters.  Please give us the chance to fix an issue before opening an eBay claim.

Customer Advisory:  Often I have found that tubes get weak due to leaky coupling capacitors or other issues in the customer?s gear, so they replace the tubes but never fix the underlying issue with their equipment causing the tubes to burn up quickly (B+ on grids, etc.).  When they insert the tubes they have purchased, the underlying flaw in their gear quickly eats up the ?new? tubes.  If your tubes were ?red plating? or running extremely hot, please have your gear serviced before inserting new tubes.  Almost never does a tube ?red plate? because it?s bad, 99.9% of the time, its something else in the amp causing this.