Some unconventional advice on picking tubes
How’s everybody doing? This month I’ve chosen to further investigate how tubes can affect your overall tone, and how they’ll ultimately play a big part in sculpting your own personal style of playing. If you’re the type that takes music seriously, you’ll most likely aspire to make music with your own inimitable signature on it. The idea here is to look at every angle and peek into every nook and cranny where tone is shaped.
This entire process can take quite a bit of time, given all the variables involved. My goal is to make your task easier, so you don’t have to spend years hunting down your dream tones. Since wonderful tones can come from anywhere in the signal chain—beginning with your fingers exciting the strings into an electronic signal, to the whole array of components it travels through, to the sound radiating from the amp’s speakers—there’s a lot to look at on the way!
The main reason why we guitarists love tubes so much is that they have a big influence on just how we touch our instruments and why. The touch factor involves the amplifier in a critical way, since it is indeed an instrument in its own right. The way you play it is just as important as the way you play an electric guitar—they’re two halves of the same whole, if you will.
A couple of summers back, Björn Juhl (of BJF Electronics, Sweden) and I, along with a couple of close friends, had a rather long and absorbing conversation concerning pedals, amplifiers and guitars. This discussion was focused largely on just how these things affected the creation of a player’s personal style. As most everyone knows, “BJ” makes some of the greatest amplifiers around, and his Mad Professor CS-40 and MP101 models are highly sought-after weaponry for anyone’s tonal arsenal. His knowledge about amplifiers and pedals is staggering.
Our discussion ran to the topic of Paul Kossoff’s own distinctive tone and style. Soon enough we were on the computer digging up YouTube videos of both live and studio clips of early Free songs. Björn pointed out to us that Kossoff would literally (as he put it) “jump for sustain!” I had to admit what I saw was no lie—you could actually see Kossoff jumping as he did that famous heavy vibrato on his Les Paul Sunburst. This is where “BJ” spelled out the whole string of factors that made Kossoff’s sound so unique.
He told us that the Marshall Bass amplifier Kossoff often used had to have fresh tubes installed in it, because if they were old, the tone would be very mid-rangy and have a lot less bandwidth. As a tube ages, the high frequencies are lost first, followed by the low bass frequencies. Then, as these frequencies diminish, the distortion of the tubes actually increases. What you end up with is a Marshall amp that distorts right from the onset of turning up the volume knob (on a non-master volume model). If you’ve ever turned up an old vintage Marshall that has fresh tubes installed in it, you know that the sound is really bright and spanky at lower volumes—it will not distort from the get-go like it will with older tubes. Paul Kossoff generally played with his amp turned up to the halfway mark (or slightly higher). He created his unique sound by using cleaner amp settings and a heavier gauge of string. This combination kept the amplifier “singing” when he applied that heavy finger vibrato.
It has been said that Jeff Beck still has an old Marshall head that has tubes permanently rusted right in their sockets… must be a great sounding amplifier, if he hasn’t bothered to mess with it. I have to wonder if he still fires it up on occasion.
Modern tubes will not last nearly as long as the famous old vintage ones—it’s not even close! I’ve seen old Marshalls that still have their original tubes, and they sound fabulous right now. The point is that many classic rock songs were recorded with old, worn tubes still sitting in the amps. A lot of the time these amps were not even serviced, because they sounded great to those who played them. The particular brand of amplifier isn’t a complication, because any tube amp will sound and react in a similar fashion when the tubes are worn. You might consider locating some old preamp tubes to simulate that old sound, if you’re looking for that type of vibe. However, I recommend that you do not use really worn-out output tubes to obtain these sounds. This is simply because old power tubes can cause damage to an amplifier if you let them go too far.
Try to obtain some “ANOS” (Almost New Old Stock) preamp tubes. You can find them for reasonable prices on eBay, or through various tube-supply houses online. Keep in mind that you can experiment with the tube’s position, but remember to double check a schematic or tube chart for compatibility in your amp’s circuit. Once you gain some knowledge, you can start substituting tubes of various types. Have fun, and see you next time.
is the chief designer of "Snake Oil Brand Strings" (sobstrings.net) and has had a profound influence on the trends in the strings of today.