When I bought my first Bruno Underground 30 I found it loaded with NOS tubes. When I checked out Tonys website I found that he prefers them for his builds. This, in turn, led me to seeking out all the information I could about NOS tubes. I was astounded at the difference between tubes manufactured in the '50s, '60s, ( and for a couple of brands into the '70s). The first thing that struck was the price for true NOS tubes. Seldom will you find singles for less than $50.00. Matched sets raise the price. Note. I'm talking true NOS. Not the latest craze on ebay or wherever where they "test" as NOS. I figure most of these are used with life left in them. Then again, considering how much better vintage tubes were made compared to current production, these tested tubes offered at a lower price than true NOS might still be a good choice. Life Expectancy. There's a huge difference between modern production and vintage production. My research led me to understanding that modern production output stage vacuum tubes seldom, if ever, last longer than a year at the most under touring / heavy usage. Vintage production tubes of the same type could last many times longer. When it comes to preamp or rectifier tubes modern production, (depending on the brand), last five to ten years. There are amps built in 1958 that still have their original preamp or rectifier tubes working like new. What you hear. Tone, breakup, blooming, sustain, long tails. NOS tubes out perform modern tubes big time. Somewhere along the line the magic was lost, (or was left to die for return on the dollar). Vintage tubes were so well built that once you owned them you could pretty much forget about them. Sure. Sometimes a tube failed but, these events were few and far between. Then again .... if you're a manufacturer building vacuum tubes ..... the fact that your product is so good that the user might never need to replace them is poor info for the bottom line. Built to last used to be a byword for a fine product. Built to fail, (a favorite idiom of modern manufacturing), guarantees the same customer will be coming back for more of the same. Anyway ....... I've come to love NOS tubes. I even enjoy wading through the maze of terminology sellers use to describe the tubes offered. Three out of four might be less than true but the fourth is a goldmine. So ..... my favorite NOS tunes. Rectifier Tube ........ '50s or '60s Mullard. The cream of the crop. Preamp 12AX7 tube V1 first stage ........ Mullard, (built at the Blackburn factory). Same as above. All other 12AX7 / 12AX7A / 7025 preamp tubes ....... '62 to '64 RCA. Possibly the best of the best. I used to use one of these in the V1 stage too but a tip from a friend told me to try the Mullard, (Blackburn), and it was a true notch up. I was both surprised and pleased. A bit more crunch in a useable way and a small up in gain. Output tubes ...... NOS Mullard EL34s, RCA 6L6GC and Amperex EL84s., (made in Holland). My favorite output tubes have always been EL84s. I love them. Vintage Amperex EL84s are light years beyond all competition. So ..... Does anyone else here use NOS tubes. Does anyone else here swear by modern production. I'm open to all responses. I post threads based solely on my opinion. Yours might differ and by reading yours I might gain insight. I would never claim to be an expert. Even after 48 years playing the guitar I realize that hidden gems are always a possibility. Thank You for any and all responses Note * I would pay almost anything for the finest example of Amperex, (holland production), EL84 NOS tubes. These are the grail in my tube life. .