Look what happened to my NOS 12AT7

[Franz 1997]

I think it's generally agreed that NOS tubes were better built with better QC, I think the issue may be - if you've had them fail - that they would have been rattling around for decades, possibly tossed around in transit, maybe passed around amongst dealers during trades, and may have developed mechanical problems. I've never had an NOS tube fail electrically, it's always been mechanically; glass breaking, heater winding fracturing etc. Also it's in the nature of things that todays's NOS tubes could well have been at the bottom of the QC pile when they were originally made 50/ 60 years ago, who knows. In the 80s NOS tubes were very cheap, in the 'military surplus' category, so they hardly got feather-bedded treatment.

[Gitfiddler]

i didn't burn through ten of them with a single amp. This was through several different fender style amps and ten was an exaggeration. I bought ten and still have a few left. It's probably more like 5 of them and 3 with this amp. And honestly, the issue with NOS tubes has always been that:

1. You have no idea whether it's really NOS
   
2. You don't know what physical or electrical abuse it's been through
3. It got to my hands being 40+ years old

People on the forums always wax poetic about the original tubes but reliability-wise, JJs have been the most reliable.

See #1, #2 and #3 above.

[Franz 1997]

This is a forum, no point in saying things just once

[jzucker]

NOS tubes are the best, the newer ones just aren't built as well. you'll pay more but in the end they'll outlast new ones by a mile.
I think I've had maybe a 1/2 dozen preamp tubes fail on me ever, and that's gigging a few times a week w several amps for many yrs, plus home use. not to mention they were already in the amps when I bought them and they're from the 1960's. I tried some newer tubes and maybe got a year or less out of them.
right back to old RCA's, Mullards, GE's etc and no problems since.

That has not been my experience and I think franz is right. When they were new, they were way better made for the most part than their modern counterparts. But the NOS Jan Phillips AT7s are junk IMO. I just bought 10 more of them but I wish I hadn't. Another one started squealing last week in the PI position where voltage and current aren't a concern. When I first got the 10 that I bought a year ago, I rotated them through several days worth of playing in either the PI or reverb driver positions and they all checked out ok but as time went on, most of them have gone belly up in a relatively short period of time in several different amps. A lower voltage vibrolux, a fargen, a morgan rca35r and a vintage sound 35.

Conclusion, electrically they check out ok, but mechanically they have been jostled around for 40+ years and you cannot depend on them. I think I will probably go with JJs from here on in. I just got a pair of NOS rca AT7s which sound great in the vintage sound but who knows how long they will last?

[Wildcat]

Amend!!!

People on the forums always wax poetic about the original tubes but reliability-wise, JJs have been the most reliable.

[John A.]

fail mechanism is them getting squeally and microphonic. Not sold on the NOS tubes. I also have been having problems with the expensive tung-sol reissues. I think I'm going to go with JJs for preamp tubes from now on.

A tech recently told me that he sees a lot of problems with the JAN Philips tubes. His theory is that the ones that are around now were made when production was winding down and QC was less rigorous. But they do sound good.

John

[wintermoon]

yeah, I never liked the JAN Phillips preamp tubes.
But I love the Phillips STR-387 and 415 double getter 6L6 power tubes, they're all I use and sound superb.
Those RCA's should last forever Jack and if they don't it's probably because you play too hard

[jzucker]

yeah, I never liked the JAN Phillips preamp tubes.
But I love the Phillips STR-387 and 415 double getter 6L6 power tubes, they're all I use and sound superb.
Those RCA's should last forever Jack and if they don't it's probably because you play too hard

They sound better than anything else I've had in there. I'll probably buy some more if I can find them. The guy only had 2. There's another guy who sells pairs of NOS Mullard 4024s for $75. I got a good deal on the RCAs though. It was about 1/2 that.