NOS Tubes--Are they worth it? or accurate?


After doing considerable investigation, I question whether it is worth it to undertake the quest of finding NOS tubes. Just looking at the volumes of discussion on audioasylum about Amperex 6922's and how many of them don't sound that good, the fakes out there, the difficulty in confirming how much use the tubes have seen. It just seems like way too much to deal with.

I know many will say, buy from the reputable tube dealers, but at what cost? Is their inflated pricing worth investing into something that has a limited life and can quite probably never be replaced? I think that looking into current production tubes that sound good would make a lot more sense.

The other issue is that many of the amps and preamps we are using them in are were not designed around the sound of these NOS tubes. If you substitute another tube, I think you are drastically altering the sound from the designer's attempt towards his version of reality and accuracy to something that is totally unrelated to this man's intentions and work.

It seems that we then end up with a mish-mash of sonics that are tailored to an individual's preference and may be far, far removed from any accuracy at all.
saxo

Showing 3 responses by saxo

On asylum, this very topic came up, and someone posted that the old NOS tubes had somewhat different electrical characteristics than, say Sovtek 6922s. So, yes, you are distorting the original design parameters by putting NOS tubes in. Contrary to your claim, many manufacturers state that they do strive to design for accuracy as well as sonics.
Pls 1, since you have engineeering background, do you believe that it is not possible to design an accurate tube amp or preamp? If, for example, you look at bench measurement frequency response on a Sonic Frontiers Power 2 or 3, you will find almost a dead flat response. You don't see that very often in tube amp reviews, I know. However, again, into an actual load, who knows? But doesn't that apply to transistor designs as well?

Regarding the SF amps, from my experience and everything I have read, listeners still find there are deviations from flat in these amps. Maybe I'm answering my own question here. That we don't know how to design a truly accurate piece of equipment.

Be that as it may, it still seems that pieces that show gross frequency response deviations show these dips and peaks in their sonics as well. So, what do measurements tell us? Something and nothing both.
Good point about the designer's musical tastes. Designers should really become intimately knowledgeable of the sound of a full orchestra as well as a jazz band, a jazz ensemble, vocalists, choirs, etc.

I guess those who think they have achieved 'accuracy' are fooling themselves as our technology and knowledge is far too limited to accomplish this.