Why Purchase used tubes?


Is it the price? I don't understand. You buy a wonderful used tubes that tests out better than perfect. What is the guarantee, after you hook those babies up to your rig, that they won't start to degenerate. NOS are surely more expensive, but brand spanking new! Would this be the best way to go if money wasn't a factor? I'm tubie newbie, but getting there...thanks warren :)
warrenh
If you are certain what particular tube(s) you favor in a given application, and you wish to eliminate as much uncertainty as possible, by all means buy NOS. But those sellers you can trust to offer genuine NOS are not cheap by any means. I've gambled on many, many tubes on Ebay and seldom been burned, most are suitable for my preamp's line stage duty. I've been able to sample a dozen 6dj8/6922 flavors via Ebay for what one or two NOS tubes from a primo seller would cost. Phono application, a different story. There, it's cheaper long term to just pay a reliable seller for tested NOS I think. Which brings up the factor of how hard a given bit of kit burns through tubes. A lightly stressed application can be considered differently than a highly stressed one.
My answer applies to all types of tubes, but for the sake of clarity my examples will refer only to Mullard EL34. This is one of the most popular tubes ever made and of all I've ever owned (hundreds), only a handful were purchased new. Many of the Dynaco stereo 70 amps in operation today still have their original Mullard EL34 output tubes on board and working perfectly.

These tubes do eventually wear out but old, conservative tube biasing circuits plus the extreme quality of Mullard leaves many of these EL34's alive and testing 80% or more of brand new.

Most of the Mullard EL34's I own were bought for $55.00 to $75.00 each (in large quantity). New stock in original boxes can go for hundreds of dollars a pair. Many times the price is driven up by a collector or avid tube nut, a person not necessarily buying only for performance reasons.

So, the question comes down to: How many tubes do you require, what are you willing to invest in tubes (considering value of the piece they're going in) and how long do you intend owning this after the investment?

When it came to tubing the EL34's in the power supply of my Aesthetix Io and Callisto, I bought the most premium NOS available to insure maximum possible performance. In my Aesthetix this is justified as I have no intention of switching brands and this equipment cost multiple times my investment in these super premium tubes.

If I bought a used Wolcott Presence stereo amp for the bedroom and wanted great sounding tubes, no way would I shell out for original boxed Mullards. Good used tubes beat the stock to death and at a price I can justify.

My friend buys really extravagant tubes, used. Telefunken 12AX7 are his favorite pick. He pays a fraction of what people do for NOS. Then, he tests them using a far more elaborate method than most - using an ocilloscope as opposed to a tube tester. He ends up with piles of incredibly good sounding tubes (better than a lot of NOS in actual use), and again, at bargain basement prices.
I'm looking for a very high quality pair of 6922s for my SET pre. Doing my homework, it seems that the Amperex Pinched Waist D Getter PQ is the Holly Grail. Man, are the nos expensive. $560 was a price I was given for a pair. I really don't know if that is fair. I would love to go NOS. What tube comes in a very close second?
I like the Siemens 7308 tubes in a phono stage they are very durable. I find that the Amperex 6DJ8 Buglboy tubes sound nice in tube output CD players, and you can find them very cheap on Agon. Good Luck.
http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html#6DJ8-2

Per Joe`s tube lore.

My favorites that I picked up on ebay....

amperex 6922 PQ white label, US made (shield, gold pins).

amperex 6DJ8 orange globe logo, Holland. (shield, steel pins).

Both are excellent tubes and matched pairs can be picked up very reasonably.

Don`t be too concerned about them being NOS unless you want to spend more money. If the sellers have mega positive feed back ratings, and until I buy my own tester, I`ll take their word on their test results.

Have fun on the hunt. I certainly did.
Siemens CCa, early 60s grey plates. $300-$400/pair.

As with the Amperex 6922 Pinch Waists, be sure you get a return privilege from the seller in the event the tubes are noisy or microphonic.
When it came to tubing the EL34's in the power supply of my Aesthetix Io and Callisto, I bought the most premium NOS available to insure maximum possible performance. In my Aesthetix this is justified as I have no intention of switching brands and this equipment cost multiple times my investment in these super premium tubes.

If I bought a used Wolcott Presence stereo amp for the bedroom and wanted great sounding tubes, no way would I shell out for original boxed Mullards. Good used tubes beat the stock to death and at a price I can justify.

To clear up any confusion, Wolcott was my reference amp for many years, it is an EXCELLENT design, both in it's stereo and mono block configurations. My comment about super premium tubes in the Io and Callisto are due to the sensitive nature of both high gain preamp and/or moving coil phono stages. Plus, only two tubes are required rather than 16 in the Wolcott.

A bad tube in a Wolcott and one of the bias lights fails to light and you know to switch it. Tube fails in moving coil phono stage and things could get nasty.

In any case, I don't want it to appear that Wolcott is not worthy because I suggested used Mullards would be a smarter buy than new in box variety. My mono blocks required 16 and at $200.00 each for "NOS in new boxes" Mullards I'm out $3200.00. Used that sound as good cost me $800.00.

Leaves more money for other things, same sound quality on both sets of tubes.
Warrenh, looks like you've been spending time reading Joes Tube Lore. If so, remember that his picks are based on HIS equipment. His greatest enthusiasm is reserved for Amperex offerings. In my system, I find that some of Joe's favorite Amperexes appeal to me less than Siemens 6dj8's from the 60's. Before I'd ever blow $560 on a pair of tubes, I'd be sure I liked the "house" sound. You can pick up Orange Globe Amperex 6DJ8's (assuming you can use 6dj8's) for a song compared to the most coveted Amperexes. I agree with Joe on those tubes, I think they're great. As to the price of pinchwaist d-getters, "fair" doesn't mean anything, we live in a free market economy. There's a very finite quantity of a highly coveted commodity and if people will pay the asking price, it's unrealistic to expect altruistic pricing. It's all a matter of perspective on the worth I suppose. To me, I don't think the difference between the "best" tube and close contenders is worth hundreds of dollars per tube. Others obviously feel differently.
My experience:
Bought new 6CA7 power tubz directly from ebay seller new matched quads turned out $<8/piece over 3 yrs ago.
Often run amps 24hrs during weekends and once-in-a-while check the bias...
Still hasn't change a notch!
Still noise-free!
Still have extra set for the amp... How's that?
Hey Photon46, I use the same tubes (Amperex Orange Globes) and agree with you that they are a good bang for the buck tube. I bought a quad for my Lamm's and since I only use 2 at a time, I figure I am set for life. They sound more refined than the stock Sovteks.
(I have heard the legendary pinched waist PQ's, in my system, and they did sound great, but not much better than the Orange Globes, IMHO. And at one tenth the cost, I'll stick with the Orange Globes.)
Warren,

No guarantee, thus buy from reputable sellers. NOS can test new but can be used. Also, tubes I believe don't have a linear curve when it comes to life span. More like dropping off a table.

I buy used to try out tubes to see how they sound in my system. The ones I like, then I buy NOS. It makes no sense to pay hundreds on NOS tubes that end up not sounding good in your system.

Matty
My tube mentor happens to agree with Tvad on the Siemens Cca. Tvad, what type of tubes did you use in your Exemplar Denon 3910?
I only like used tubes to play with. If used ones make a "difference" in my system, then I'll go buy NOS ones. However, some of the best dealers will computer match the used tubes. These will be virtually identical and should sound and wear that way. Try upscaleaudio.com
Warren:
Like you, I have been, comparatively, a late arriver to the 'tube party'. However, once there, I chose to get involved. It is good that you have a mentor that you trust...it will save some headaches. With that said, there is a wealth of info on various tubes if one does his homework. With all of that said, IMNSHO, as the old saying goes "in your system, in your environment......". What one person loves and raves about may just as well NOT be so good in your system. Experience, and adequate tube rolling and listening is the REAL teacher.

In my experience, I agree with Matty that the wear curve is NOT linear. I also strongly agree with Kurt_Tank about being sensitive to the 'bang for the buck' realities.

As regards your first question, about buying truly NOS, in my experience, some of the REALLY desireable tubes are getting the point of being SO picked over that sourcing TRULY 'New Old Stock' tubes is becoming questionable at best. Does anyone REALLY know the history of the tubes that are landing in their hands? It would seem that the best that anyone can do is test and quantify.
After reading Joe's Tube Lore on AA, the Amperex 6922 PQ, US (shield, gold pins) sound excellent. The Holy Grail Amperex (same with the pinched waist) are out of my league. Joe says the sonic qualities are very close, however. Also, another interesting thing is going for the 5751 as a substitute for the 12AX7 Telefunkens and Seimens. Anybody with listening experience comparing the two? He absolutely, resolutely says the best of the 5751 kills the Seimens.
12-07-06: Warrenh
My tube mentor happens to agree with Tvad on the Siemens Cca. Tvad, what type of tubes did you use in your Exemplar Denon 3910?
Stock. I bought a Western Electric 396A to try, but I sold the Exemplar before I tried it. Keep in mind my Exemplar was a balanced version and the tube compliment is different than your Exemplar Denon 3910 (unless you too have the balanced outputs).

12-07-06: Warrenh
After reading Joe's Tube Lore on AA, the Amperex 6922 PQ, US (shield, gold pins) sound excellent. The Holy Grail Amperex (same with the pinched waist) are out of my league. Joe says the sonic qualities are very close, however.
I did this same comparison. I found the Amperex 6922 PQ White Label USA to have a similar sonic signature to the pinch waists. Close enough to prevent me from spending the extra on the pinch waists. However, the pinch waists did sound better...much larger image and extension without being etched. The extra cost wasn't worth it to me, though. Many others disagree.
Joe's Tube Lore is an excellent guide, though I have found quite a few tubes to vary from his descriptions, depending upon the component used. In two different amps, for example, the Mullard 2493 (6922 equivalent) sounded much more balanced and tonally pure than either the Amperex Pinched Waist or the Telefunken CCa. A friend and I also heard the Pinched Waist in his DAC, and they sounded more etched than his stock tubes. Go figure. I have yet to find an Amperex (save for a 6X4 rectifier) that didn't sound too bass heavy...could be the room, who knows?

The guides are useful, for sure, but your own ears will be the final judge.

Now, the Siemens 1960s (not 1970s) CCa's...yeah, those are sweeeeeet! Definitely get the MBG, however, in case they are microphonic.