DK Design VS- Reference vs Signature

NOS means exactly that...New, Old Stock. These are unused vintage tubes. Used tubes cannot be called NOS, but NOS is a term commonly misused by tube sellers to describe any vintage tube. That's why a buyer of NOS tubes should always ask the seller if the tubes have ever been used.

Dabarrie,
Please be careful.
First bleed the amp down, (playing it softly, turning it off, to drain the power from the output).
Then turn off the rear rocker unplug it--remove the top plate--in the rear you will see two tubes, surrounded by 'rings'. Try to not touch anything but the tube itself!!!
Wearing gloves or using something to keep the oil from your hands from transferring to the tubes, gently, gently rock the tubes front to back, while pulling up gently. It will seem stuck, but will pull lose. Note the bottom pattern of the tube.
Take both tubes out--then put the tubes back in matching the patterns. Be careful, as the tubes are somewhat delicate-if you misalign the bottom you can bend them-worst case, break the tube.
This shouldn't happen though, just be gentle.
Plug the amp back in--let it stablize, by turning on the rear rocker switch, then wait about a minute.
Hit the front 'on' switch, and the tubes will cycle to power in about 30 seconds.
Don't make any evalutations for 24 hours--and I would leave the amp on constantly for the first day.
With our circuit, we feel that the tubes should have a life of about 10,000 hours playing hours.
Let me know if I can be of any further service.

As to the question of "how can they be called new".
I suppose that it depends on which 'expert' you wish to believe.
Recently, I have spoken to several 'experts' and each time was given different information about this.
The most compelling of the experts, meaning the one who appeared to know the most, (how can I know for sure)--told me that the definition of NOS was not that New Old Stock means New in the classic sense, but New as it relates to measured performance. He indicated that, if the tube,(regardless of ownership or use) measures at least 65, and it's old stock it can be considered to be NOS. This sounds counterintuitive to me also, but that was his explanation.
I welcome any 'experts' who sell or trade in tubes to give their definitions, as I don't pretend to know the right answer. Heck, I'm the guy who said that Amperex circa 8/62 NOS tubes retail for about $250. because that is what another 'expert' told me--and he's a tube dealer.
TVAD says they can be had for less than half that at virtually any time on ebay. While I would personally feel more comfortable buying from a tube dealer, (maybe that's who is selling on ebay), that's a choice for everyone to make on their own.

Caveat Emptor, as always.

Best,
Larry R. Staples
LSA Group
President/Designer

Tube dealers sell on E-Bay just like they do on Audiogon or their own websites or over the telephone. E-Bay, Audiogon and personal websites are simply marketing opportunities...virtual storefronts. One should not make the mistake of assuming legitimacy comes by way of one venue and not another.

Legitimacy and trust comes via an established history of positive feedback, either here, on E-Bay or by word of mouth, regardless of the product being sold.

LARRY YOU ARE THE MAN!!! This is excellent service for an excellent product.

Thanks

Larry,
When I took the older pair out and replace it with the new pair. Every thing was fine. But when I put the older pair back in, the right channel tube lost its vacuum. It stop lighting up. I really don't understand how this could have happened. Can you explain to me what happen and How can I prevent this from happening?
Ron