Handling vintage tubes - Many vintage tubes were labeled with ink designed to fall off easily. So do not touch it! If you get it wet at all, it may go away right in front of your eyes, and just shipping and pulling it in/out of the box can damage the logo. If the box is an original vintage box, open it carefully using a butter knife under the flap. The ends can tear right off easier than you would believe and some people prize the boxes. First time start-up and flashing lights - If your gear has filaments that are constant on, first install the tubes, plug it in according to manufacturers instructions, and let it sit for a few hours. I know you want to hear it right away…but if there has been a small amount of gas that has developed since the tube was tested, it’s best to let it burn off before turning the tube all the way on. So go smooch with your significant other or play with the dog or something. Some small signal tubes will make a burping noise when they warm up. Don’t sweat it. Also, 12AU7, 12AT7, and 12AX7 that come from Mullard or from the Mullard or other European families may flash when first powered up from a cold state. Also normal. What is NOT normal is a flash from power tubes. If this happens turn off your amp immediately! Biasing and matching basics for power tubes - If you are new to biasing… carefully read and follow the manufacturers instructions. Pay attention and make sure you are not in a hurry, stoned, or distracted. Even the most seasoned tube-head will tell you mistakes do happen. Remember, the voltages involved here are lethal. There are two things we look at when matching tubes with the partner they can live with. The way they idle and the drive capability of the tube. Think of your amp as a car with an engine for each wheel. If you put the car in gear and drove off at an idle, it would be important that all the engines were idling the same. Otherwise the engine with the high idle may run hotter than the others. That's what biasing is about. Without negative bias the tube would be at full throttle and would burn up in a short time. So negative bias is added to bring the tube to the idle point desired. Some manufacturers give you a specific point like 50 millivolts, some may give you a range of say 40 to 50, 55 to 65, etc. The higher the number the hotter the tube is running, and the shorter the life, though the difference may be small. Contrary to popular belief running them hotter does NOT guarantee the best results. IMPORTANT LIFE-SAVING POINT!   When installing new power tubes, you have to remember that your old tubes, as they became weaker, required more negative bias to maintain the same idle current. Before plugging in your fresh new set of power tubes, you must turn the bias all the way down on your amp before plugging in the new tubes! This is a very important step, as if you have the bias turned up too high, it may shock the new tubes when you turn your amp on, causing the tube to overload, which could cause a premature failure, and with some amps, may take out a resistor. If your amp uses a cathode or auto-biasing circuit, then you don't have to sweat this step, but if you adjust bias manually it is very important. If your amp has one bias adjustment for the whole amp, or per pair or quad, you should have matched tubes. Some amps that have individual bias adjustments for each power tube. In this case you may not need tubes matched for idle current, but we believe it makes sense to get them matched anyway, so they will all age gracefully together. Upscale Audio includes matching at no extra charge. You cannot match power tubes on a typical tube tester. In fact there are only a couple very rare models that will allow you to get close to the voltages needed and allow you to read the parameters correctly. We use custom-built testing equipment that is the best in the business. We burn in and test power tubes at real voltages, and we test them for shorts, grid leakage, and excessive current draw before and after burn in to help minimize the chances of using your amp as a tube tester. Click here to read more about our test equipment. Tube Life, noise, and do I leave the power on - We get asked this question a lot. With a power amp you would typically not leave it running 24 hrs a day. Power amps produce heat, and they use a bit of electricity. Pre-amps, DACs, and other products that use small tubes are another question. Regardless of what anyone tells you… I have not found a definitive answer to this question. Tubes age in a couple ways. One is they lose emissions over their lifetime. In other words, they run out of gas. Tubes don't just "quit" suddenly. They lose their drive capability gradually. Figure a tube like a 12AX7 or 6922 to be good for about 10,000 hours, and you leave it on 24 hours a day, well you do the math. There are 8,736 hours in a year. So when did the tube go bad? It depends on how picky you are. It's like a tube of toothpaste. Kinda peters out at the end but it seems you can always squeeze out a little more. Some products (and audiophiles) are more picky than others. I recommend to folks that want to upgrade to premium new old stock tubes that they do it while their stock tubes are good. That way you have the cheap ones working and available should you decide to sell the pre-amp. The other way tubes age is they become noisy. The noise may sound like popcorn popping softly in the background, or it may become a roar, and it can happen to any tube, including new ones. The most common reason that I have found for tube noise is the coating on the filament becomes compromised. This can be made worse by turning them on and off a lot. That's the best way to guarantee trouble with tubes, so don't sit there and turn your gear on and off constantly. Usually it's a good idea to leave your gear on during the day if you plan on listening to it a different times, then turn it off at night, or if you'll be away for a few hours. Microphony, tube dampers, and tube tapping - I will say this only once: DON'T TAP ON TUBES! You can permanently damage them. ALL tubes are microphonic to a greater or lesser degree. Whether or not you here anything as you bang away will depend more on the tube's function in the product than the microphony of the tube itself. In some positions you will never hear anything, even with the worst tube. Other positions you will hear something even with the best tubes, and at that point you make judgements about the degree, type, and how long it sustains. Tubes are supposed to make noise when tapped on! If a tube is truly microphonic and is in a position where it is critical you will know it. It will feedback as you play music and be so objectionable you'll turn it off. So should you use tube dampers? Try them. Some folks like them. Others say tube dampers make the music sound sterile or hard. A small amount of microphony can be pleasing as it can give a sense of "air". So the answer will vary on the system, your taste, and the individual tube you put it on. If you don't like 'em you can always take 'em off. The 6DJ8/6922/7308 family of tubes is a special lot and are prone to be sensitive to vibration. That does not mean being microphonic by definition (though some are). What's this mean for you? In some high gain pre-amps you may hear a slight ring when flipping some switches. This may be normal as it is the grid wires picking up vibration through the tube pins. We listen to each tube in circuit and ship tubes according to the product it goes into to give you the best results. But if you own a preamp from Audible Illusions or CAT (to name a couple) and you get a slight ring for a second when you bang on the pre-amp or flip switches, don't sweat it. Unless you plan on playing bongos on your pre-amp while the music playing, but if that's your plan you may want to re-think your strategy. One More helpful hint: We recommend that you have something hooked up to the output of any tube product when they are turned on. This applies to pre-amps, amps or anything else. If a tube preamp is left on for an extended period without being hooked up to a power amp, mute it.