1. Tubes are tested and meet the below listed Gm specifications of an UNUSED tube. No other sales claims about New Old Stock tubes are either expressed or implied by us.
2. These tubes have been tested and meet or exceed manufacturer published specifications of transconductance (Gm) for the specified tube type. This is based on the Design Center Rating System (average/bogey tube ratings), according to the original RMA standard M8-210. All tests are made prior to shipping on calibrated professional test equipment testing for transconductance and/or plate current where applicable. All audio power output tubes are tested and matched under maximum typical operating conditons on a Tektronix 576 curve tracer, and matched to plate current draw, with regards to published curves in the RCA RECEIVING TUBE MANUAL.
3. NOS tubes fall within the Gm characteristic range of an average tube, as published in the RCA RECEIVING TUBE MANUAL. This publication also states "Individual tubes, like any manufactured product, may have characteristics that range above or below the values given." It is important to note here that a common misconception of tube testing is that every unused tube, new or vintage, should test at 100% of the meter scale of the tester, or at exactly the number listed as the nominal Gm on a digital tester, such as the Amplitrex. In reality, very few tubes test exactly at these readings, some will be above these numbers, most will likely be below. As the RCA manual states that the characteristics may fall in a range above or below the bogey values. For this reason, the original RMA specifications were plus or minus 20% for Gm for an unused tube, and minimum good would be up to 50% lower than the nominal number.
4. NOS tubes may or may not have their original box, and on occasion may have partial to complete loss of the original label. Original boxes will be supplied whenever possible. Tubes that have been previously stored under poor conditions will be cleaned, preserving as much of the original label as possible.
5. Physical and cosmetic aspects of new old stock tubes will vary widely, and cannot be accurately used to determine if a tube is unused or used. Factors affecting appearance include length and quality of storage conditions, factory burn-in or other factory testing, dryness or humidity adversely affecting tube labels, pins, base adhesive, and the tube box, and previous handling of the tube. Getter flashing appearance will also vary widely with NOS tubes. The appearance will be affected by such factors as getter composition, burn temperature, length of factory ageing or burn-in (if any), and location of the getter inside the tube. Tube cosmetics such as getter flashing, tube pin condition, label condition, and presence or absence of a box are not accurate indicators of the strength or past history of the tube. We rely on professional test equipment to indicate the Gm and plate current measurements of each tube, and by comparison with industry standards, determine the status of each tube.
I purchase the tubes from overseas, they are not individually boxed when I get them. So pins can get bent in shipping. These tubes have been sitting around for decades. But we test every tube and for power tubes we match them when we get them. Tubes are burned in for 24hours (like Tube Depot). Once they pass the test, they are boxed and the box is marked with a code for matching purposes. After our testing we know the tube is good to be shipped. Any tubes that do not test a certain strength do not go out in the mail to customers. Because air contacts the pins when its not in a socket this can cause corrosion depending on how and where the tubes were stored over the years. We pride ourselves in what we do, and we respect your journey to better tone.
Basic info on glass. We want a good, hard vacuum inside a tube, or it will not work properly. And we want that vacuum to last as long as possible. Sometimes, very small leaks can appear in a tube envelope (often around the electrical connections in the bottom). Or, the tube may not have been fully "degassed" on the vacuum pump at the factory, so there may be some stray air inside. The "getter" is designed to remove some stray gas. The getter in most glass tubes is a small cup or holder, containing a bit of a metal that reacts with oxygen strongly and absorbs it. (In most modern glass tubes, the getter metal is barium, which oxidizes VERY easily when it is pure.) When the tube is pumped out and sealed, the last step in processing is to "fire" the getter, producing a "getter flash" inside the tube envelope. That is the silvery patch you see on the inside of a glass tube. It is a guarantee that the tube has good vacuum. If the seal on the tube fails, the getter flash will turn white (because it turns into barium oxide). NOS tubes will have different dark spots on the actual glass tube, this is normal.
(ANOS) Almost New Old Stock
(ANOS) Almost New Old Stock are used tubes that have tested with "new" parameter results. We dont normally stock ANOS, with exception of our 6p14p ANOS Military Spec. We decided to stock these so folks who have not tried the 6p14p output tube out can and also get a very high quality tube at that. These tubes will have more dark spots on the glass from use. Remember military spec tubes last 5,000hours which is much longer than a current production tube. If your not ready to purchase NOS but still want to see what you've been missing ?
1. Questions?? Please contact us.
2. As with all used electronics, this item, unless stated otherwise, is sold as-is with no guarantees.
All tubes are NOS (New Old Stock) unless otherwise specified as used or ANOS. All tubes are tested and guaranteed to function within specified limits for 14 DAYS FROM INVOICE DATE. Be sure to try your new tubes when they arrive. Do not operate power tubes without having you amplifier’s bias checked/adjusted. If you have questions about biasing, see a qualified technician.
Only defective tubes will be considered for return. We do not guarantee any level of performance of tubes in your test equipment nor do we accept returns of tubes you bought for an amp that you later sold. Please do not ask.
Please email a description of the problem, and the amplifier you’re using. We will send you an RMA number. If you have a received a tube damaged in transit, you MUST retain the original shipping box and all packing materials. You will be asked to take pictures of the shipping box, materials, and item so that we may file a claim with our insurance carrier. No cash refunds whatsoever.
You are responsible for shipping costs on returning items to us. We cover reshipping costs back to you for qualified returns. Use appropriate packing materials (NOT a padded or un-padded envelope!) to return tubes. The original shipping carton/packing-materials is recommended. Any tubes returned which are inadequately packed will be discarded and NO credit will be issued.
All returns must include your payment receipt, a note describing the problem and whether you would like credit or replacement. The RMA number must be clearly written on the OUTSIDE of the package. Any package without an RMA number will not be accepted. Defective tubes must be returned within 30 days of purchase, NO exceptions. All tubes, boxes and tube packaging must be returned in original condition. Tubes/boxes not returned in original condition will not be accepted.
Boxes like these in the background are what Military tubes were stored and shipped in. We ship all tubes in individual boxes.
We were asked what else we do other than testing and matching before we ship your tube out. This we have found is one of the best ways to clean the tubes and pins without using a solvent and potentially taking the writing on the tube off. NOS tubes were not individually boxed originally, so they can look very dirty even though they are NOS.