By Steve Graham
Tubular Obsession Confession Time
Have you ever had an audio obsession? Never happened to me, not much!
I became preoccupied with headphone listening for a while. I still do it occasionally, but I really became obsessed with headphone amps. The line of Earmax HPA’s from Germany became a particular fixation after reading a Ken Kessler review in HiFi News and Record Review many years ago. I actually saw one in a display case at a stereo store some years ago but the shop owner didn’t offer me a chance to actually touch it, let alone listen to it. That was probably just as well, as at the time I couldn’t have afforded it, much less ustified the cost to my significant other. justified the cost to my significant other.
I built an HPA that was a sort-of Earmax clone but it didn’t really grab me, so it got shoved to the back of a closet and was later dismantled. Another DIY HPA that was a tube-and-opamp hybrid followed. A marathon tube rolling session with a bunch of my own, and the loan of other 12AU7’s, demonstrated that the sound was highly dependent on the brand and vintage of these tubes.
Up to that point I had never really bought into the whole equipment burn-in thing. Yeah sure, I’d let new equipment warm up for 10 or 15 minutes before listening, but that was about it.
I found an online data sheet, and apart from filament current, a 5963 tube is a near match to the 12AU7. Funny thing, reading down the data sheet, the 5963 was actually intended for computer use back in the day! I popped in a NOS 5963 and after my usual ten minute warm up, listening commenced.
Apologies, but I must go off on a brief tangent. Every time the first Back to the Future movie comes on TV, I have to watch the first hour or so. The first time I saw this movie was on a plane to Los Angeles, my first visit to California. This was back in the day when everyone on board watched the same movie, or else read a magazine or went to sleep. I’ll never forget hearing fellow passengers laughing out loud at Marty McFly’s antics.
The house in the movie that “belongs” to Dr. Emmett Brown is the Gamble House, a real house in Pasadena. The garage in the movie where the electric guitar “incident” takes place is not on a busy street, that’s just movie “magic”. The real house and garage are on a quiet lane off a fairly quiet street.
I’ve been to the Gamble House twice when in the Los Angeles area on business. As well as being a tube geek, I’m also a bit of an architecture geek. The Gamble House, named after a member of the Gamble family (think Procter & Gamble) who built it in the early years of the 20th century, is breathtaking. The house, furniture, light fixtures, carpets, stained glass windows and even the piano are an artistic tour de force – all designed by the architect brothers Charles and Henry Greene.
If you are ever in the LA area it would be a shame not to set aside a couple of hours to visit this stunning example of Asia-influenced Arts and Crafts architecture. The house belongs to a historic trust and can be toured. Just search “Gamble House” for more info.
Where was I? Right. The sound of the 5963 was dreadful. Computer tube, I thought, what more could I expect. Then an audio buddy suggested I let it run for a while. Mumble, grumble, OK, what have I got to lose? I let the amp run overnight, fed by a CD on repeat. Twelve hours later, not bad. Another twelve, even better. Forty-eight hours after first turn on, darn nice.
I’ve learned my lesson. Electronics, especially tube electronics, need to be broken in. I usually like to run new equipment for 48 hours minimum before having a quick listen. Serious listening doesn’t commence until at least 100 hours of running time has accumulated.
I’m at or beyond my word limit. More tube rolling and HPA stuff in part 10.
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