Stuff I Like and Stuff I Have Done: Totally Tubular

I like good music, and I appreciate good sound equipment. Although I don't have an ear sensitive enough or educated enough to hear the difference between types of speaker cables, I can tell the difference between bad stuff and good stuff. I was introduced to "good stuff" by my good friend, whom I will call Friend 1. He took the dive into the hi-fi world with a handmade British CD player and amplifier and $3000 speakers. He has since upgraded significantly. Since becoming attuned to the existence of good equipment and the people who like it, I have discovered that I know a few audiophiles. They are nice people, difficult to distinguish from your average Joe (they are men, so "average Jane" wouldn't fit here). A good way to ferret out an audiophile is to speak effusively about how much you like the sound generated by a Bose system. This is sort of like talking about Velveeta at the Cheese Board in Berkeley. Turns out most of them HATE Bose stuff. One told me that he was stuck at a party where a Bose system was playing loudly and he actually became nauseous after an hour of listening.

Audiophiles come in many flavors. The more ecumenical of them appreciate flavors they do not themselves embrace, but that they recognize as being good. Truly confident ones don't criticize other flavors at all. Rather, they leave it to their equipment to persuade you that their flavor is the best. A few examples of my friends' flavors:

Friend 1: Nice audiophile equipment with mostly solid-state circuitry. Speakers that sort of look like normal speakers. Sound quality for a jazz CD that will make you cry. Probably into his system for about $10k.

Friend 2: Krell Amplifier with no cooling fans, instead milled out of a solid block of aluminum (about 300 lbs). B&W speakers that are curvy works of art. Apparently they (the speakers) leaked a gallon of oil onto the floor after a particularly loud New Years Eve dance party. (Is that cool or what to have speakers that somehow need a bunch of oil in them?) Were taken away and rebuilt by the manufacturer. Don't know how much he is into this system for, but it is certainly mid 5-digits.

Friend 3: Has a massive collection of '80s New Wave vinyl records. These play on a high-end turntable through incredibly heavy 7-foot-tall Magnepan speakers that are only like one inch thick. Some people buy a BMW 335i, but this guys owns a Toyota Matrix and about a BMW 328i worth of audio equipment.

There are other audiophile friends in various stages of craziness, but these ones help illustrate why it is difficult for me to find a reasonably-priced stereo system whose sound is pleasing enough to listen to. I have been spoiled.

So if it isn't obvious from the little projects you see on this blog, I'll say it here explicitly: For one reason or another, I have a real need to be using my hands to build something from time to time. Not every day or even every week. But I need to build a real object sometimes in order to feed a part of my brain that needs that sort of thing. What better thing to build than a stereo? I have relatively vivid memories of my father soldering together a Garrard stereo kit when I was three or four years old. They had to keep the project in a locked room so that I wouldn't break in and work on it myself.

In the last few years, there has been a resurgence of interest in vacuum tube audio equipment.
I won't go much detail here about this. Suffice it to say that 1) Vacuum tubes produce a rich sound--to some tastes it is better than sound from modern solid-state equipment; 2) I have a professional interest in the persistence of old technologies like vacuum tubes; 3) Tube amps can be VERY expensive; and 4) There is a rich selection of low-end DIY tube amp kits out there. Google around about all of this. You do not have enough time before you die to read all of it.

The Project

So I did a little research and bought a K12 tube amp kit from Arizona Hi-Fi. It appears that they are not selling these any more. The closest substitute seems to be the K-8LS kit. Note that this gives only 8 watts per channel. But, as you will find when you google around, people seem to think that although all watts are created equal, "tube watts" are more equal than others. And this kit has been very well reviewed by discerning audiophiles. The kit was easy to assemble. I was able to solder the whole thing together in an hour or two on a Saturday. The box is recycled from a Costco bamboo wood organizer system. I built the circuit board upside-down (I soldered in the components on the back of the board rather than on the front) so that I could make an enclosure with the tubes sticking out into the air as far as possible. I have not actually made the cover yet, but I will get around to it. This is important, as there are a few capacitor leads that carry enough voltage to kill someone. The only hiccup with soldering things on upside-down was the volume pot. The volume knob works in reverse--the 0 is on the far right, and 11 is on the far left. I think knobs work like this in the southern hemisphere, right?

To complement the amp, I got a set of what I like to describe as low-end high-end loudspeakers. They are PSB Alpha B1 bookshelf loudspeakers. Like the amp kit, audiophiles have identified these loudspeakers as having much higher sound quality than their price would suggest.

It took a few days for the tubes and speakers to burn in and for the sound to start to be really crisp. The little system makes a beautiful, warm sound. Even running on iTunes from my laptop, the sound is remarkably clean. The best validation of the system's quality came from Friend 2 above (the one with the megabuck Krell). I invited him into my office to have a listen, and he had me download a great test song, "Eclipse" by Joao Gilberto. I played it for him, and he couldn't get over the sound quality. He had been chasing down a ground hum in his system, so he was especially pleased with the dead silence during quiet parts of the song. Friend 1 suggested that I buy "The Köln Concert" recordings by jazz pianist Keith Jarrett and "The Art of the Trio, Vol. III" by Brad Mehldau. On my little system, the Jarrett recordings in particular can make you cry. I have also had good luck working with "Music for 18 Musicians" by the Steve Reich Ensemble playing in the background.

The amp (note the volume--it is at about 3 or 4, not 7 or 8). The tube give off a nice warm glow when the music is playing: