Before you get too absorbed in the love fest the mutual admiration society of vacuum tube amplifier fans are holding, it's time to interject a little reality.

Whether you are a tube fan or not, it is a fact that you would be hard pressed to find another area of electronics where the preferences of at least some of the users flies in the face of the way most of the engineers and manufacturers see it and the prevalent theories they learn and use to create their products. Many tube proponents have rejected all of the engineering design criteria and performance meausrements engineers use to judge the performance of audio equipment because they say that it doesn't correlate with what they hear. So the market for tube amplifiers which was nearly dead for most of the last 40 or so years has been rekindled by a niche looking for what most main stream manufacturers would call esoteric products. However, the big boys, the ones who used to actually manufacture the tubes themselves, RCA, GE, Sylvania, even Telefunken have never gone back into the business of making them. There have been no new vacuum tube designs in about 40 years. Many of the people who manufacture these tubes now are of highly dubious skill in making precision parts that consistantly perform properly. Furthermore, most of the designs, the claims of the manufacturers not withstanding are old reworked versions of designs known 40, 50, even 60 years ago. At best they have been reworked or tweaked to a minor degree. The kind of parts which were so common for manufacturing tube sets 50 years ago such as electrolytic capacitors with very high voltage ratings, transformers with suitable windings for biasing vacuum tubes must now be procured from a relatively small source because the rest of the electronics industry has retooled and these once common parts are now exceedingly rare and costly.

You buy at your own risk. There are thousands of products currently out there. Many thousands more if you consider all of the older discontinued models. If you are a true died in the wool audiophile, one can almost guarantee that whatever you buy you sooner or later won't like it and when the novelty wears off, you will become disillusioned and look for something else to buy in its place. Very few are entirely happy for any extended time with what they already own. Another objective truth is that the nirvana they seek rarely if ever exists.

The fact is that vacuum tubes begin to deteriorate from the minute they are first turned on due to the heat. Normally they age so slowly that the decline in their performance is imperceptable. However, this depends to a certain extent on negative feedback which compensates for these changes among other things. But many new amplifier designers have rejected negative feedback because it is not in their lexicon of what sounds good.

The purchase of a low power class A vacuum tube amplifier will necessarily restrict you to a small segment of the speaker market where efficiency is a major concern. That or you will have to adjust your expectations to modest volume levels. Depending on your musical tastes, and the size and acoustics of your listening room, this may or may not be OK.

The high end rolloff exhibited by many vacuum tube amplifiers because of the limitations of their output transformers may be useful in offsetting the shrill sounding loudspeakers audiophiles initially prefer especially since they have rejected equalizaton, driver level controls, tone controls and filters, and all other manner of modifying the frequency response of audio systems. The only other method they accept is to look for wires with bizzarre inductance/capacitance characteristics which also act as filters of one sort or another.

Cavaet Emptor, buyer beware.