“If you stick a modern production tube in an old vintage amp, you may be a little disappointed with the tone”: Do vintage NOS tubes really sound better? Here’s what you need to know

KT66 power tubes.

As a self-proclaimed tone chaser, I’ll try almost anything in pursuit of better guitar tone. Years ago, intrigued by the hype around NOS tubes and the promise that they could magically transform my amps into tonal bliss, I invested in a stash of pricey NOS 12AX7 preamp tubes just to see what the fuss was about.

So, what are NOS tubes (or, valves, in UK parlance) anyway? ‘New Old Stock’ (NOS) refers to tubes made decades ago and were never used. This was mostly during the golden era of tube manufacturing in the 1950s to early 1970s, as they were produced in massive quantities for military, broadcast and industrial applications. The saying, ‘They don’t make ’em like they used to,’ might be true for these tubes as they were built under strict quality control.