Do military/industrial tubes sound better than regular ones ?

Military vacuum tubes are built to specifications that ensure resistance to failure in high vibration environments and tighter tolerances³. They are not necessarily for the military, but are manufactured to meet these requirements³⁵

^{Perhaps tighter tolerances may impact the sound, but I believe the ones labeled for the military are no different than the ones labeled for any other use, probably coming off the same line, only labeled differently.}

Well, Brent from Audio Tubes has both regular 12AU7 RCA black plates and military/industrial ones, all from 50s, not sure early or late 50s. He also calls industrial Command Series. I have regular ones installed, so I could order a set of military/industrial, burn them in for 100 hours and then compare. Return them if I hear no difference and lose 20% which would not be much, those tubes are $99 each and I would need three of them. I just don’t want to start with this and don’t want to buy more tubes right away, last week spent $450 for a matched pair of 12AX7 NOS Mullards longplates from 50s. They are excellent tubes, hard to find, so I bought a spare pair from Brent.

Russia also has their military grade tubes. The Russian Rockets Reflektor 6N23P are a popular tube still used by many especially in heaphone amps. These tubes were used by the Russian Space program back in the 70's. I still have a set in an old tube amp. I'm sure there are many others.

I've had good luck with JAN/Phillips 6922 tubes but I don't think being military is a guarantee of better sound or longer life.

Since I make no claims to be a tube guru I started trying to go through a plethora of emails I filed away from the 6SN7 guru who bestowed that cache of vintage 6SN7s (and some 6922s) upon me. I thought I remembered him telling me that the tubes that the military had contracted out for were made to better withstand vibration as many of them were going to be used in different avionic applications.

Anyway, I have a crapload of emails on those tubes and I wasn’t finding the one I was looking for, but I’ll paste a blurb from one of the first ones I found:

The W in WGTA is the designation for "ruggedized" construction. Thicker mica supports, extra support rods, smaller bottle ... all supposed to reduce the effect of physical shock/vibrations.

That was referring to a pair of 1974 Sylvania 6SN7 WGTAs that I don’t think were made for military applications as I think that (at least our) military must have been done with vacuum tubes by then.But another pair of 6sn7s he bestowed upon me when he was cleaning out his cache of tubes he no longer used, and these really are jewels, were two ’52 Sylvania "Bad Boys" and I have to think that these were military as he sent them to me in their original packing box (not tube boxes, but a heavy duty box) with a faded placard labeled "SPARE PARTS" , and also states that the contracter was "PHILCO CORP." and "MFG BY [a faded "Sylvania is typed in] "DATE INSPECTED" [9-19-52" is typed in, faded but still legible] under that "PACKED FOR OVERSEAS SHIPMENT" and in the bottom right hand of the placrad is a little picture of an anchor with "ORD" in the middle of the anchor and "U.S.. NAVY" at the bottom.

So I assume that these were made by Sylvania for the Navy, and these are tied for first place as my absolute favorite 6SN7 sonic presentation so far.

My two runner ups were a pair of black glass RCA VT 231s and a pair of Tung Soll VT231s ("probably NLT 1947"). I think maybe the reason that military tubes have the favorable reputation that they do is because a large percentage of the tubes that were made way back then were made for the military and therefore a lot of the vintage tubes that are being sold today may have been made with a military contract in mind so when we find one we really like, it’s not unusual for it to be "military surplus" of sorts.