Tubes

E-Bay is risky. Even moreso for a novice.

These are reliable tube sellers:

• Brent Jesse Recording
• Vintage Tube Services - Andy Bouwman
• Upscale Audio
• Tube Audio Store

+ 1 tvad, better to be on the safe side, if you don't have a way to check the valves. Even if you do, have a way to check valves, one mans good on EBay is another mans junk.

Matched valves with ONLY 20% left in the tank are sold all the time as matched valves. They are matched for about a year if you're lucky..

Lets just call it worn evenly..  In some cases a small valve at 50% will last some people a lifetime, others maybe just a year or two..

Ask for quiet valves.. ASK, don't assume they will be.. Don't squeeze on the 6SN7 or the 12AU7. The 12AU7 is an easy one, Telefunken or Mullard Blackburn.

6SN7, is a different story, that valve is a Jekyll and Hyde history.. BE CAREFULL and choose a good pair.. 

PSVANE? How are you liking that valve OP? That's another Jekyll & Hyde manufacture, you just have to listen and adjust from their.. 
Telefunken and Mullard are going to be your friend with PVANE, I suspect. :-)

Regards

+1 @tvad 

Shout out to Jim McShane for tubes, too.

I have purchased the Melz 1578 from Svetlana_ua via ebay (100% positive feedback)(6 hole) several times out of the Ukraine. Zero Problems.
Have also purchased the cheaper Melz 1578 from markcohen-7 via ebay also from Ukraine with zero problems. Can still get "New" never used in the box NOS from these sellers and they ship immediately. Unfortunately they take a few weeks to arrive. Worth the wait. The Melz metal base are wonderful.

Ive bought a few items from Russia, solid transactions with reputable feedbacks. I haven't had the chance to test the PSVANE 845 yet. Will try tonight. 

I've never had the PS but read somewhere they take about 48 hours to open up. I like the paypal method of being able to protect your purchase also. Maybe it is my ears but the Melz sound better after a couple of days running. You probably know more about tube construction than I do.
Cheers.

Go to Brent Jesse recording ,
vintagetube services,   For the real deal there were Millions of   tubes made ,they were much better made ,far better tighter vacuum and well worth the effort ,every brand sounds a bit different ,call Brent he will guide you in the balance you are looking for and you can get a 2 year warranty for an extra reasonable fee.

Avoid eBay. 50/50 and not worth the risk to the gear. I have bought lots of vintage tubes from several sources. Those listed above are all top notch. Add Grant Fidelity - sells the spin-off brand from psvane - should be trusted. For eBay, I’ve had luck with all the rectifiers I’ve purchased but not so for input tubes or power tubes. 

I just bought from Upscale a matched pair of Gold Brand Sylvania vintage 6SN7 (GB-6SL7WGT) for about $100 apiece for my Cary phonostage.  They are excellent, especially very quiet for the phonostage.  I’m not sure that Upscale has more of these, perhaps they could be found elsewhere.

http://tubedepot.com/ TubeDepot is another good source for tubes. 

+1 @tvad!
I wouldnt trust ebay for such a purchase.....
I have used Brent Jessee, as well....pleasant to deal with, great advice and selection...in this case I believe you get what you pay for, with diminishing returns.....
Good luck

I bought several tubes from ebay, including a rare nos sylvania 5751 disc getter and a nos rca 7025 gray plate, both of which are installed and sound great. You pay your money and take your chances....it helps to look at the sellers feedback. These sellers both had thousands of 100% feedbacks. These tubes were installed into a Tavish Design classic phono preamp. The third tube, a 12au7, is a GE JAN military tube purchased from Kevin at Upscale Audio. This particular 12au7 is one of the quietest available, adding excellent detail, low noise and a blacker back ground.

I've bought lots of NOS ebay tubes from reputable dealers with return policies. The new stuff I get from Viva or other reputable dealers. Not a big deal. 

PSVANE 845 WE replica from a trusted Ebay user with a solid longstanding 100% feedback turned out to be mistake. Very noisy tubes probably at the end of their life. I requested a refund. 

How are the Shuguang 845 C from Upscale audio? Are these better than Chinese Electron 845 that come standard on many amps? What about compared to PSVANE and other brands? Anyone with experience ? 

Tube World has great carefully selected tubes. Not the lowest prices but quality is high.

Just received a pair of Linlai Elite 6sn7 tubes for my tube DAC.  Excellent sounding tubes.  I bought these after hearing some top end 300B power tubes in my nephew's amp.  Those were stunning and even beat out the Western Electric reproduction tubes that were supposed to replicate the originals.  Linlai seems to be doing a great job producing some if the great tubes of the past.

I own hundreds of vintage tubes.  It is a game of 30 to 50 percent rejects when you take into account testing and real world performance.  Just because a tube tests at 100% does not mean it will perform well.  Heaters may draw to much.  The tube may be extremely microphonic.  A quote from Tung Sol is the best way to test a tube is in the system for which it is intended.  If new tubes from EH and others are available you are best to go that route with The Tube Store, Tube Depot, or Antique Tube Supply.

Viva is generally priced somewhat lower than many other tube suppliers, ships fast, and has lots of NOS tubes available.

We have PSvane KT88 MK II in our 40 watt tube amp. After about 50 hr break in they sound sweet and full, better than the 6550 EH tubes.

I don’t understand the paranoia about eBay. There are many, many dealers of tubes who’ve thousands of feedback on eBay. I buy there exclusively because tubes are generally much less expensive than other dealers. I recently acquired new Gold Lion KT88, Tung Sol 6550’s, a set of brand new NOS original Sovtek Winged C EL34’s from a dealer in Britain, and the best Grey Psvane CV181’s from the New York eBay dealer who sells nearly every type of tube. I’ve never once had a negative experience with eBay dealers. Simply do your due diligence and purchase from reputable sellers.

I own about 200 tubes and a modern tube tester. I've bought on eBay, but I'd be very careful buying there having had both good and bad luck with sellers. This is especially true with NOS, but you can also buy substandard current production tubes. Unless you own a good tube tester, you have no idea what you are buying, so you must pick someone you trust. 

One major problem is that many eBay resellers use vintage emission type tube testers that don't test tubes for transconductance or test at a high enough voltage that the tube will see in a circuit. Even they don't really know what they are selling! 

Another problem is manufacturing tolerances are all over the lot for current production and a lot of new tubes that test below spec still get sold as "New" rather than rejected for QC.  Even the very reliable sellers mentioned above have to weed this junk out if they want to maintain their good reputation. If you pay a little more, believe me, they're worth it.  

Good luck!

Let me ask you do you leave your tube amp on all the time ,even when your not listening to it ?

No, of course not. This is class A 845 high power tube. I’m Afraid to leave amp unattended for more than 5 minutes, not to mention all the heat