Afterglow

As a young boy, I was always fascinated by the glow emitted by vacuum tubes neatly implanted in the back of our glitzy sound gear which, in turn, gave our family a marathon of blissful music, especially on Sundays. I would patiently and intently watch the tubes’ afterglow hours after our stereo system had been turned off; much like a moth drawn to a flame, I was hypnotized by its slowly fading ember-like phenomenon.

The glow is actually caused by a burning filament inside the tube-like glass, akin to an incandescent bulb. I would later learn in high-school science class that those heated filaments were the very life of the contraption which would catapult the world to a new electronic order. Its applications empowered 20th century mankind to communicate, travel and create new things, among other benefits, with ease. But alas, as convenience made way for more practical solutions, the compact transistor eventually eased out the vacuum tube as an electronics star.

Andrew Michael Sevilla, owner of AMX Tube Audio, was as enthralled as I was by the vacuum tubes’ afterglow. The only difference is that, for him, it was a love at first glow that he turned into a living. At age six, he built his first crystal radio and was stunned when it worked. During his early days as an electronics engineering student, he would wire tube stereo amplifiers for allowance and tuition money.

“There were instances when I built them from kits, like EICO, Heath, and Dynakit sourced by people in Clark,” narrates Andrew. “I remember assembling a Heathkit colored television. But most of the time I would build them from scratch. I would buy all the parts in Raon where you can find all brands aplenty — RCAs, Telefunkens, Siemens, Philips GE, etc. Passive components were Allen Bradley, Centralabs, Sprague and Mallory. Output transformers were Acrosound, Zebra, Sansui and Stancors for the budget-conscious. But when budget became a real concern, I started winding my own transformers.”

When he graduated from college, the transistor was already king. Andrew momentarily set aside his “first love” and founded a company which produced transistor-based electronic products. But like they say, first loves never die. In Andrew’s case, as it was for me and I’m sure millions of other audiophiles around the world, love is truly sweeter the second time around.

“In 1991, after having built lots and lots of Mosfet solid-state amplifiers for discos and PA applications, I went on a buying trip to Hong Kong and was surprised to discover that tubes were making a comeback. Back in Manila, I searched out my old notes and books and designed a 6550 UL amplifier. I built it and started savoring again the good old days,” a proud Andrew recalls. “To this day, building tube amplifiers remains my passion.”

Now, don’t get us wrong. The transistor could well be the invention of the century. It is the IC (integrated circuit) that has brought us to the Age of Information. It has given us transistor radios, the compact two-way radio communications known today as cellphones, the more compact and lighter satellites, and a myriad of gadgets we enjoy today. But why is the little king who reigns in computers and telecommunications now taking a backseat to the Audiophile Kingdom, and why is it rejected and humbled by so many musical artists who prefer the old and bulky tubes?

Andrew says: “Often, the first thing I get asked about the amplifiers I build is: ‘Why do tube amplifiers sound better than solid-state amplifiers?’ (The fact is I still build solid-state amplifiers for applications other than hi-fi). For one thing, a person’s perception of better sound is completely subjective. One thing we need to understand is there is no perfect amplifier. Amplifiers all have a certain amount of distortion. But what psychoacoustic experts have determined is that some distortions are more acceptable than others. Some types of distortions you can live with, some kind of distortions you will actually love, some types are just so horrible that they hurt our hearing sensibilities. Tube amplifiers reproduce music with the type of distortions that would actually enhance the hearing process. This, I believe, makes tube amplifiers more musically enjoyable, while transistor amplifiers that claim to have lower measured distortions are spitting out small amounts of distortion which hurts our hearing and leads to listening fatigue.

“So which is better? I recommend choosing that which brings you more listening pleasure. Many audiophiles have found that tube amplifiers — despite their inefficiency, bulkiness and high cost — give them more listening pleasure and enjoyment; music that they can live with and actually make their lives better. We are all hedonists, are we not?”

So, are vacuum tubes here to stay? It depends, Andrew qualifies, on whether this technology will find other applications in the near future. “For one, semiconductors can’t withstand nuclear radiation; therefore, all our computer servers, mainframes, and telecommunications and navigation systems will conk out in a nuclear attack. But a vacuum tube will not. Scientists are deep into developing miniature, vacuum, field emission diodes, and triodes for use in electronics in hazardous environments. If and when this technology is developed, it would be very interesting to see if it would at all be applicable to audio.”

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For comments or questions, please e-mail me at audioglow@yahoo.com or at vphl@hotmail.com. You can also visit www.wiredstate.com or http://bikini-bottom.proboards80.com/index.cgi for quick answers to your audio concerns.