You don't have to read many tube dealer ads to discover that "matched" versions of their power tubes are available at slightly higher prices.  Yet, most players and technicians really don't understand what matching is all about, and what they get for those extra bucks.  Let's take a look at matching.
 
Please note that we are talking about matching power tubes such as 6L6, 6V6, 7027, 6CA7/EL-34 and 6550/KT-88.  I can tell you from long, hard experience that matching power tubes affects the sound of your amplifier more than any other tube.  Compared to random tubes, an amplifier with matched tubes will provide slightly more power and a reduced hum level.  In most cases, the improvement in sound quality will be slight, but worthwhile.  It is up to you to try matched tubes to judge for yourself.  Personally, I install matched power tubes in the highest quality amplifiers, and always in amplifiers that demand them.
 
You should be aware that most musical instrument amplifiers have a single bias adjustment, or none at all.  Use matched tubes in these amplifiers because there is no way to adjust out bias differences between tubes.  Typically, if you put random tubes in one of these amplifiers, one tube will run hot, while the other will run cooler.  As a result, the life of the hot running tube is reduced, and you have to pony up for a new pair sooner than expected.  By the way, it is especially important to use matched tubes in amplifiers like the Fender DeluxeÔ.  This unit runs a pair of 6V6 tubes far beyond their voltage ratings (430 volts, 25 mA for you tech types), and it doesn't take much of a mismatch to smoke both tubes!
 
On the other hand, matching both sections of small-signal tubes such as the 12AX7, 12AT7 and 12 AU7 has proven to be a silly idea.  I discovered the performance improvement, if any, was measurable, but not great enough to hear.  We don't offer matched small-signal tubes for this reason.  Save your money if you wish to buy from others!
 
By the way, always replace your power tubes as a set.  This is true even if only one goes down.  If you don't, you are gambling that the tube you didn't replace will last as long as the new one.  This is highly unlikely, and you will end up taking your amplifier in for service much more often.  I know professional players who routinely replace all of the tubes in their amplifiers after 4-5 performances simply because they can't afford to have their amplifiers quit on stage!  Let me repeat: always replace your power tubes as a set.
 
So what do you get when you buy matched tubes?  They will be matched only in terms of bias current.  In other words, if you put two perfectly matched tubes in an amplifier, each tube will draw the same current.  This is called "single point matching."  Mismatches of 5% to 10% in current draw are acceptable in most amplifiers.  This is the best you can expect for the low cost "standard match" we offer.  
 
Be aware that tube aging affects matching.  The first 100 hours of playing may change matching enough to become a problem.  After about 500 hours of operation, there is much less change in the match.  For maximum tube life, we recommend checking the bias settings in your amplifier at those times.
 
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