Avoid Tubes.RS

[SpiderWars]

I've pretty much given up on NOS. It seems so many times you're not getting NOS you're either getting UOS (used old stock) or just failed/bad tubes. Nevermind actually being matched. My last attempt was getting square getter Chinese preamp tubes from this very site. First I only got 2 out of 3 with a shitty Psvane tube thrown in "as a gift". But that Psvane was super duper micro...and it's a Psvane (i.e. garbage). And when I finally got 3 tubes one of them had so much flash between the upper spacers you know it's not just used but like 90s 5150 used.

 

[JTyson]

I would still go for certain NOS preamp tubes, but there is too much risk involved with supposedly matched NOS output tubes.
I remember when “matched” meant within
1.5 of each other and it was common, but it seems that time has long passed.
I still have a stash of well matched Winged C SED’s, my fav EL34 from that time, but I stocked up on EH 6CA7’s that are well matched, hopefully they will get me by for awhile for non critical applications

 

[FourT6and2]

I would still go for certain NOS preamp tubes, but there is too much risk involved with supposedly matched NOS output tubes.
I remember when “matched” meant within
1.5 of each other and it was common, but it seems that time has long passed.
I still have a stash of well matched Winged C SED’s, my fav EL34 from that time, but I stocked up on EH 6CA7’s that are well matched, hopefully they will get me by for awhile for non critical applications

Well the tubes that arrived that didn't immediately fail in my tester were actually matched quite well. But a matched set is worthless if one of the tubes is defective.

 

[CDawg]

I'm sorry to hear about the seller and your tube problems. I believe the CC company will pull through and it will work out for you. Soon as you mention defective or fraud the CC should side with you. Not many people talk about the bad things associated with NOS tubes...

If you don't have specific measurements then it's pennies on the dollar from me. The more information you provide the more I'm willing to pay. I'm willing to pay fair market value for high quality tubes from reputable sellers. I give preference to an Amplitrex or a Maxipreamp/Maximatcher. A recently calibrated TV-7 is my next choice but I'm paying less. Other testers get less money. Generally if a NOS tube isn't 110-120% GM or someone swearing up and down repeatedly that this is in fact a new tube I won't touch it.

Preamplifier tubes are easy to buy and I don't worry about much more than microphonics and noise. Power tubes are a whole other beast. Some of the power tubes like a GE 6550A or a Philips 7581A are built to what I would call tight tolerances where a new tube doesn't have much variation in measurements like current draw or transconductance between them and it's fairly easy to make matched sets with anything you buy. Every EL34 I've ever seen is all over the place in terms of current draw and transconductance. Buying or making matched pairs is relatively easy. Buying or making matched quads can be difficult. Sextets or more is a nightmare. The probabilities of putting together sets becomes increasingly difficult the more power tubes are involved and it can get expensive if you have to buy 15 or 20 NOS tubes to make a matched sextet.

There's so many tube companies gearing up production right now I wouldn't sweat anything. There's like 20 companies like Emission Labs, KR, Moon, etc. that are already making incredible tubes that will compete with or destroy the best of NOS and they keep launching new lines all the time. Fezz Audio just got EU grants to open a new tube factory in Poland for 3 products. Looks like we're getting a preamp, power and rectifier tube from them. I'm guessing it'll be an EL34 and not a 5U4G since everyone makes those. No clue on the preamplifier tube.