I Love Tubes

Growing up with tubes

When I was a kid transistors were a new thing. Every device that needed high voltage used tubes. Radios, record players, amplifiers, televisions (another new thing), and electrical devices of all types used vacuum tubes. When you turned one of these devices on you had to wait a minute for it to warm up before it started working. The top of the sets would get very warm and the backs were open with perforated fiber board backs to let the heat escape and provide some degree of safety from the hot tubes and high voltage capacitors. The backs were easy to remove to provide access to the tubes when they needed replacing.

Good Weak Bad

Replacing the tubes wasn't too difficult. Servicemen were everywhere. They would even show up at your house with a huge case of tubes and swap out the offender in a jiffy. If the owner were the confident type who could manage to open the back and poke around inside without touching a capacitor and stopping his heart he could do it himself. Not only were servicemen everywhere but tube testers were everywhere. A cabinet full of tubes with an array of testing sockets on the top surface. They were in every appliance store, hardware store, drug store, & five and ten cent store. Really. You simply plugged your tube into the proper socket and hit the button and a meter told you if it was good, weak, or shot. Then you just found a new replacement by number in the drawers underneath the tester and bought it, cheap. American tube manufacturers made the best tubes and cranked them out in massive numbers. The stock still exists if you know where to look.

Pretty Cabinets

So the sets were larger then to accommodate the tube circuitry and provide sufficient ventilation. They were furniture, oh yeah I should add furniture stores to the tube tester list. Furniture stores sold radios and record players so they had records, needles and tubes also.
Back to the furniture, the sets became a part of the experience. They looked cool for decor, they got warm, they gave off a smell I still love, they glowed out the back and out of thier illuminated dials. They also sounded warmer, a hard thing to describe. Solid state proponents will argue this one adamantly forever but I think the tube amplification sounds better. There are a large percentage of musicians and hi-fi enthusiasts who agree enough to keep the vacuum tube industry alive today.

Whats a Tube?

I love tubes, if you follow my blog you know that I like old stuff. One of the old things I really like is devices that use vacuum tubes. What is a vacuum tube? To simplify the theory: If you pass an alternating current through an electrode and get it hot enough to glow, like a light bulb, it gives off electrons. Put a cool grid electrode next to the to hot one to catch the electrons and you have a one way current. You just changed AC to DC. Now add at least one more electrode and you have an amplifier. One thing necessary for this to work is that the circuit has to be in a hard vacuum, again like a light bulb. A harder vacuum is needed so the glass is thicker than a light bulb and the glass bulb is smaller and narrow. A vacuum tube.

Baseball Games on the Radio

In my watchmaking shop I listen to a 1946 Crosley tube radio. It receives signals on two bands; The AM band and the Short Wave band. It also has inputs in the back for a phonograph so people could amplify their record players through it. I connected a jack to the input so that I can play my Ipod or an FM reciever through it. Yes I lose the stereo doing that but this thing sounds cool. It's one big speaker puts out a nice full sound and there is a wide range tone control. Tube circuits just sound great. It takes a minute to warm up before any sound comes out then it glows out the dial and the back. The funky swirly bakelite cabinet and huge analog dial are just way cool.
Tubes n' Blues

All the amplifiers I use to perform blues music are tube circuits. Guitar players have their own reasons for preferring tubes and talk about sag and distortion etc. As a blues harmonica musician I can only say that if you are going to amplify harmonica, it will sound better through tube circuits. And besides I like old stuff, remember? Old amps are waaay up there on the coolness factor. Funky styling, point to point wiring, real wood cabinets all add up to desirability in my book. You have to modernize the power cords, those two-prong plugs are life-threatening dangerous. So that's a serious place where older is not better. Also disconnect any 'suicide switch' that may be found. It was a grounding polarity switch that was there to hack the weakness of the stupid two-prong power setup.
Besides upgrading the power cords I always buy a complete set of new old stock tubes for each of my amps. Then I put the originals, or at least the tubes that came with the amp when I got it, into a box as spares if needed. An unnecessary expense but one I have never regretted. A purchase of NOS tubes is an investment. The supply is getting smaller and demand is always there. Good quality old tubes can always be resold very easily, even used. I usually buy JAN (joint Army Navy) tubes which have heavier plates and mounts to withstand bouncing around and less than ideal conditions. That is because my amps get bounced around in the back of my pickup truck and stuff and...well they are just better tubes.

Treat em' Right

If you follow my recommendations and get a tube amp you have to treat them a little differently than solid state amps. They have to warm up before any sound comes out. Once warm it is best to keep them warm. Leaving the amp on the whole gig is better than turning it off and on each set. Some amps have a standby switch that keeps the tubes heated up while switching off the output till needed. Also they don't take kindly to spending the night in a vehicle where they are exposed to extremes. An amp tech..Hell it was Cesar Diaz! (look him up) told me that you should not let your tube amp spend the night in conditions that you would not want to spend the night yourself. Also you will have to find a tube amp technician to take care of the hums, clicks, pops, crackles, silence and any other problems you may encounter during your use and abuse of the amp. Do NOT just take it to the local music store to get serviced. Unless it is new under warranty and I'm not talking about new amps here. First ask around among other musicians who have old tube amps to find out who the local amp gurus are. Perhaps it is the local music shop technician. But find out first. Ask guys that know their amps, not all working musicians do. Find a good amp tech whose work you like and build a working relationship with him. These guys are good to know.

Play around with your amp, try the knob settings in different ways until you discover that sweet tube tone. There are books written about setting up and diaing in tube amp tone. If you are tempted to buy one you may just find that all it ends up saying is "play around till you find what you like." Learn how to dial your amp in in different venues, in the dark, in a rush etc. Get to know your amp and build a working relationship with it too.

I love tubes.