Tubes: The Old Verses the New
Or to put it another way: Everything you could possibly ever want to know about N.O.S. (new old stock) tubes… and more! As an electric guitarist, it’s proabably a safe bet that you’re constantly on a quest, seeking that edge that will give you that ultimate tone—this kind of OCD seems to go with territory and I wouldn’t be exaggerating if I said it’s what drove me to begin building effects pedals in the first place. And as guitarists we’re all aware that tubes are the sonic foundation of many legendary guitarists’ electric sound: Hendrix, Clapton, Jeff Beck, and Angus Young to name just a few. But how much of a part do N.O.S. tubes really playin achieving great guitar sounds? In this article I’ll give you my two cents worth, my own real-life experiences of using N.O.S. tubes along with a dash of historical and technical info—after reading this you might not be a tube guru—those guys came from another era, the 1960s—but you’ll certainly be a whole lot wiser when it comes to these archaic, hot, high-voltage devices.
What is a N.O.S. Tube
By the early 1970′s many of western electronics companies, such as Philips (Mullard, Sylvania) had switched their production from the manufacture tubes to transistors. Tubes were still manufactured for specialised applications like broadcast television and radio transmission and the demand from the guitar and audiophile Hi-Fi industry sustained production of miniature signal (preamp) tube types (12AX7, 12AT7, etc) up until 1988. From then on the only tubes being manufactured were in Soviet Union (Russian and Chinese) factories. All modern manufacture tubes originate from these eastern factories.
Although tube manufacture ceased in the west over quarter of a century ago, billions and billions were manufactured on the production lines over many decades, and small percentage of this staggering quantity still survive to this day, unused and in their original boxes. These are new old stock tubes or N.O.S. tubes for short. N.O.S. tubes have a reputation for being superior quality to Russian and Chinese tubes. Because of this and the fact they’re a finite resource, i.e. they’re no longer manufactured, they are more expensive to get hold as time marches on.
N.O.S. Preamp Tubes
A preamp, or more properly a signal tube does the job of amplifying voltages. A guitar amp typically has anywhere from one to around five of these tubes depending on it the number of features it has (channels, send return loops, gain stages, tremolo, reverb pan, etc). A N.O.S. 12AX7 tube can typically cost from around $50 to $100, sometimes a lot more for rarer, older tubes, such as the 1957 Mullard 12AX7 pictured above. A modern manufacture 12AX7 tube sells at around $10 to $20. the quality of materials, reliability and tone make them worth the coin. The V1 position is often cited as the critical tube to substitute in guitar amps. This is because it’s the first amplification stage and a good N.O.S. Mullard or Sylvania tube in there can work wonders, ensuring low microphony, hiss and hum to give some desriable tonal improvements in amps and Effectrode pedals.
There are many working guitarists who talk themselves out of trying out N.O.S. signal tubes imagining they can’t afford them but there’s a strong case for investing in them. Here are my thoughts: Firstly, they really are better quaility than modern tubes—the vast pool of technical expertise and superior alloys utilised in tube construcution back in the 1960s were light years ahead of the what’s available today. Secondly, the lifespan of N.O.S. signal tubes can easily exceed 10,000 hours, which means even if you’re paying $100 a tube, that’s 1 cent for each hour of use—that has to be a cheap ride by any measure—the expense of your guitar strings, beer or just lighting the room you’re playing in will far out exceed this. Don’t be put off by investing in a good tube—life’s too short.
N.O.S. Power Tubes
But what about N.O.S. power tubes, such as the 6L6 or EL34? Power tubes have a considerably harder life then preamp tubes as they’re doing a great deal of work pushing electrons around to drive the loudspeaker and consequently they wear out more quickly. Their lifespan is determined by the type of power amp circuit they are utilised in—the power rating and circuit topology (push-pull or single-ended)—but somewhere between 1000 to 2000 hours is a reasonable estimate. Because N.O.S. power tubes have a shorter lifespan and they’re in shorter supply than signal tubes they are generally more expensive. But are they worth paying for? Well perhaps not in a bar gig situation where their tonal benefits might not be fully appreciated by the audience or even in a band practice session, however you might want to consider them in the studio. In a recording situation you’re attempting to capture a snapshot of your best performance and tone for posterity—you want to get this right.
So do power tube make a significant difference to the sound quality? After all, they are way downstream from that critical first gain stage., a good tube can make a difference downstream of this in any position in the circuitry. Not only can power tubes yield improvements in reliability but also in sound quality. For example, Jim Fish of Wilson Valves, Golcar, Huddersfield.