Tubes!? 
        The dominance of tubes -- or valves, as the British
        like to call them -- evaporated more than half a century ago when transistors came along.
        They were replaced in much the same way that CD took over from the LP. They became
        yesteryears technology. 
        But, like the LP, the idea of using tubes for audio
        purposes never died. Instead, tubes have had a life-span longer than probably anyone
        expected, and they enjoy a comfortable niche existence today for audiophiles who could
        never warm up to solid-state sound. As a result, we feel it appropriate to dedicate
        editorial space to tube-based products, hence Jeff Stocktons review of the Antique
        Sound Lab AQ1003 DT integrated tube amplifier that appears this month.  
        Who listens to tube electronics today, and why?
        Surprisingly, its some of the of the most influential audio reviewers on the planet.
        They swear by tube sound. One of those is Marc Mickelson, the SoundStage! Networks
        editor-in-chief. As for why, Ill let him explain: 
        
          What do I like about tubes? Everything except having to
          replace them when they wear out. Audio absolutes are hard to come by because there are
          exceptions to every rule, but products that use tubes simply sound more lifelike than
          those that don't. There's a richness that gives instruments and voices the character of
          those we hear around us, and an ease that overcomes the unnatural stridency of some
          digital playback especially. Tube electronics are just easier to listen to, because they
          reproduce everything in a more authentic way -- at least to my ears. 
         
        Another person on our staff whose preference leans toward
        tubes is Vade Forrester, who reviews quite a few tube products on SoundStage!
        Heres what he says: 
        
          Actually, I hate tube amplifiers. They are big, heavy,
          and hot, and they cost more than solid-state amps. They also have inferior high- and
          low-frequency extension, and theyre fussy about what speakers and other equipment
          they will work with. Worst of all, the tubes regularly wear out and require replacement,
          which is often expensive. But I hate solid-state amplifiers even more. They are often
          tonally threadbare, dont do microdynamics well, dont throw a believable
          soundstage, and even though their bass usually goes deeper and has more slam, it sometimes
          doesnt sound much like music. So tube amplifiers are, for me, the lesser of two
          evils. 
         
        As you'll see in Jeff Stocktons review, he was also
        won over by tube sound. 
        However, not everyone is as keen to praise tube gear, and
        there are legitimate reasons why transistors supplanted tubes. There are many who call
        tubes "distortion generators," mainly because tube amps have higher levels of
        distortion than solid-state amps and, in general, their frequency response is often not as
        flat. There are also those who criticize tube amps for being underpowered, not to mention
        overpriced when compared to solid-states amps. Then theres the problem of tubes
        wearing out, as Marc and Vade pointed out. Not only is it is expensive to replace tubes,
        but their reliability is suspect too. Its no wonder the world moved to transistors. 
        But tube amplifiers have a quality thats undeniable
        -- visually and sonically -- and there has always been much debate about why they sound
        the way they do, which is exactly why most people still swear by them. Some cite the fact
        that their distortion characteristics, while not as impressive on paper as those of
        transistors, might actually be more pleasing to the ear. Others have said that the
        rolled-off highs and lows that some tube amps exhibit make them sound more forgiving,
        which can again make for a more pleasant sound. To me, these things seem plausible. 
        Others, though, have different theories. One of those is
        designer Derrick Moss of Aurum
        Acoustics. Derrick created the cost-no-object Aurum Integris audio system, which
        features a six-channel amplifier -- four channels with tubes and the remaining two with
        transistors. Obviously, Derrick is a man in the middle, using the best technology where he
        sees fit. In his opinion, the charm to tube audio electronics might have mostly to do with
        the simplicity inherent in the design.  
        
          [A tube amps] old-school bulk demands circuit
          simplicity: theres only so much you can squeeze into an acceptable-size chassis. In
          contrast, with solid-state, a circuit might be schematically a hundred times more complex.
          Kept simple, a good tube amp or solid-state amp treats the signal very even handedly
          across the spectrum and it comes out musically intact. Trying to make things too complex,
          though, may endanger the musical rightness. 
         
        Derrick points out, however, that this is purely
        speculation and that theres more to the tube-versus-solid-state debate than the few
        simple points that audiophiles like to fixate on. Furthermore, tube amps dont just
        come in one "flavor." There are numerous circuit topologies and many different
        tubes. The most ambitious tubeophiles sample different brands of the same tube, often
        finding certain sonic qualities in each and then settling on the tubes whose sound they
        like the most. You certainly cant do that with transistors. Subsequently, there are
        a multitude of reasons why tube amps might sound different -- not just compared to
        solid-state amps, but compared to each other as well. 
        I keep a tube amp on hand myself -- Zanden Audios
        Model 600 integrated amp -- and I pull it out from time to time when I tire of solid-state
        sound. Its big and heavy, and it runs hot, but theres a richness to its sound
        that no solid-state amp that Ive heard can match. Yesteryears tube technology
        is alive and well in this century, and it appears as though its going to last for a
        long time to come, even into the next century. 
        
Doug Schneider 
        E-mail comments to the editor@goodsound.com. 
         
        
        
         |