Large collection of NOS NIB tubes

[Gasman]

I have an interesting problem - hopefully a welcome one - that I need some advice on. I joined diytube.com precisely to solicit advice from members of this forum. Let me begin.

I am a professional musician and a guitarist who plays tube amps. In the late 80’s and early 90’s, I worked as a graduate assistant in the electronic music department while doing graduate studies in composition at the University of North Texas. During my time there they were effectively purging the old analog gear in favor of digital stuff that was then becoming available. I was tasked with cleaning out their old parts storeroom. My supervisor instructed me to throw away a sizable box of tubes. I glanced in and realized that they were all NOS NIB tubes of all sorts, and there were maybe at least a dozen or more 12AX7 preamp tubes - just what my Mesa Boogie Mark II-C+ used. I did NOT throw out the tubes.

In nearly 20 years, I have had to buy but a few 12AX7s. My Boogie is very easy on output tubes, so until about a month ago, I have not needed to replace them (26 years on a quad set of 6L6GCs; not bad). However, I recently suffered a huge loss of power in my Boogie, so I reasoned it was time to replace the output tubes and decided that it might be good to do a retube of the entire amp. I began researching tube manufacturers and retailers and it began to dawn on me that I very well might be in possession of a small gold mine worth of NOS NIB tubes.

I really had basically forgotten about the box of tubes. A few years ago, I had a friend who builds hi-fi tube amps who traded me some high end bicycle parts for a handful of tubes, but after the 12AX7s ran out, I lost interest. I do have some 12AT7s which work well in one of my preamp slots, but I prefer the 12AX7s. So, there the box sat, forgotten.

However, as I began doing my research, I came to realize that I am in possession of Mullard 6CA7/EL34s, Sylvania “big bottle” 6CA7/ EL34s, Sylvania “big bottle” 5AR4/GZ34s, and other Amperex, DuMont, and GE tubes. I’m guessing that I have maybe 150 tubes, mostly labeled GE, but about 90-95% are NOS NIB. Whoever had been in charge of UNT’s tube stock had all of the used tubes clearly labeled and boxed as such. The rest of the boxes are pristine and most look like they could have been manufactured in the last couple of years. Aside from a light coating of dust on some of the boxes, they look brand new.

I am painstakingly inventorying the entire lot to make sure that all of the tubes match their boxes, that I note the country of manufacture, that I note any additional markings on either the glass or the base, that I note the color of the ink, that I note any other distinguishing features, and that I research high prices on the web for tubes which are identical.

So far, after several hours of work, I have logged only 23 tubes and I have come up with an approximate retail value of $2,850. I do not have testing equipment, but based upon my experience with the 12AX7s that I have used from this collection, I would be absolutely confident in asserting that all of the tubes which are not marked USED are indeed NOS NIB. I suspect that because of their vintage, most of the USED tubes are still of some value. Given how the supply of tubes was kept and managed, I imagine that tubes which were totally spent were disposed of.

I know that I have some 6CA7/ EL34s and 5AR4/GZ34s that are the tube amp equivalent of the Holy Grail, but my amp uses 6L6GCs. I will not have any use for the rest of these tubes either and I would like to sell them, preferably as an entire lot. Do other forum members have suggestions as to who might be interested in such a large purchase of such tubes? What would be a fair percentage of retail value to expect in such an exchange?

I will labor away on the inventory over the coming days and maybe weeks. When I am finished, I will be happy to share my findings with forum members who might be interested.

I would appreciate any advice other forum members might have to offer.

I have cross posted on the tube 101 forum as well.

[Ty_Bower]

I would like to sell them, preferably as an entire lot.

What would be a fair percentage of retail value to expect in such an exchange?

A large box full of "a hundred fifty tubes, can't tell you exactly what they all are, untested, but I promise that most of them a really really good ones" should probably sell for about $75. Maybe someone who has been to a hamfest could chime in.

If you had a photo of the box that clearly showed the ends of the tube cartons, and it had their types written on each, then the value would increase significantly. If you had individual photos of each tube, carefully set on the table beside its own carton, then you would gather the highest value for your collection. Buyers might expect to purchase less than the full lot of tubes. In short, the return you get on your sale will be directly related to the level of effort you can put into documenting exactly what you've got.

Honestly, it seems like you believe your collection has high value and you want to sell it for a large sum with minimum effort. Unfortunately, you will likely have to convince the buyers of your collections value. You can try Craigslist and hope to find a local buyer who is willing to bring his own tester. If your potential buyer can physically handle the tubes, he is most likely to be willing to pay top dollar. You might try contacting some of the better known tube resellers (Tube Depot? Tube Store? Jim McShane? Triode Electronics? Antique Electronic Supply? ESRC?) and see if any of them would want to buy them off you. Keep in mind that whatever they buy from you, they would need to resell at a profit. It is also probable that they would not be able to turn around and resell them in short order. They might be willing to pay you 10% of what they would typically ask for comparable tubes? I don't really know, I'm just guessing at this point.

Of course, the obvious solution is just to put the whole box up on eBay. Again, the better your photography skills, the more you can expect to collect.

[Gasman]

You misunderstand me, I am in the process of doing as detailed an inventory as is possible. I have maybe around 15-20% of the tubes cataloged in a database and will be posting the information when it is complete. I will also take detailed digital photos for each tube and its box as I get inquiries.

I am not expecting prices or even offers at this time. I am merely asking for guidance from a community of people who may be able to help me proceed in the best manner.

Here is a sampling of the tubes that I have inventoried so far, in the following format:
(type - brand - country - quantity - features)
6CA7/EL34 - Amperex - Great Britain - 2 - orange globe; Mullard relabel
6CA7/EL34 - Sylvania - USA - 2 - big bottle, v halo getters
6CA7/EL34 - Sylvania - England - 2 - single halo; Mullard relabel
5AR4/GZ34 - Sylvania - USA - 6 - big bottle

As to the country of manufacture, I list it exactly as it appears on the tube. Thus, some indicate "Great Britain" and some indicate "England." I have further details entered into the database - i.e., other markings, color of printing, etc. - to further aid in identifying and dating the tubes. All of the above tubes are NOS NIB and all appear to date from the late 60's to the early to mid 70's. I have pristine condition boxes for each of the above.

From my research, I know that the above are indeed valuable tubes, but it is exceedingly slow entering all of the information into my database. I carefully remove each tube from its box and examine them individually with a magnifying glass to verify that the printing is exactly as I describe it. The reason I haven't given you more information is because I am still in the process of compiling it. I know that diytube.com members will have detailed questions and I want to be able to answer them fully and accurately.

I am not hawking these tubes yet. I am simply trying to establish where to go once I have identified what I actually have.

I will appreciate any advice that you may offer. What other information should I be looking for when I examine the tubes and boxes?

[kevco]

I think it's very important that you not assume that ANY of your tubes are good and of value to anyone until they have been fully tested on a calibrated tube tester by someone who knows how to use it. Good "looking" tubes in original boxes are not necessarily good tubes. Many people removed tired old tubes from service and placed them into the boxes of their new replacements to be saved as spares. It sounds as if the dept who originally owned these tubes probably contract bought mostly GE tubes, so boxes are probably similar. I think there's two ways you can part with these: One, sell them in bulk, untested condition to one of the major resellers and let them sort them out and make a handsome profit on the good ones. Or two, get yourself a calibrated dynamic mutual conductance tester or acquaint yourself with somebody who has one (try Audiokarma) and find out exactly what you have and sell them as such. They're only worth serious money if they're documented as good or better yet, matched.

[ChrisAlbertson]

I have an interesting problem - hopefully a welcome one - that I need some advice on. I joined diytube.com precisely to solicit advice from members of this forum. Let me begin.

I think making a list is a good start but I also think you are going to have to test these.

Also about their value. If you were a trusted, well known company and said that you tested the tube then you can ask full price. Private party sales don't get nearly so much. If the tubes are not tested then it is just an "old tube" and has very little value.

[battradio]

I would suguest finding some one who would test the tubes for you , with a good tube testor such as a hickok .

I had 3 Sylvaina 5AR4's NOS recently that where bad when tested , i had these about 15 years , all the other tubes i got in the batch where good



I would love to have the Sylvaini 6ca7's but im cash poor at the time .

Do you need any equiptment repaired or need other parts or speakers for trade

[Gasman]

Good points, all. One of the reasons I wanted to sell the lot in bulk was because I don't have test equipment. I'm not sure whether or not it would be worth it to purchase a piece of gear such as a Hickok. After I divest myself of this cache of tubes, a lowly emission tester would probably suit my guitar amp needs.

First I must continue the slog onward with at least documenting what I have. I have some strange tubes some of which I have no idea what they were for. Some were for amplifiers, reel to reel decks, original Moog synthesizers, and whatever other tube powered audio gear they had in the old electronic music department at my alma mater. At the very least, I'd like to see someone actually use them. Every single one that I have actually used has functioned perfectly and exactly like I would expect it to, so hopefully several people will indeed get some good tubes.

Thanks for your input and keep it coming.

[Ty_Bower]

I'm not sure whether or not it would be worth it to purchase a piece of gear such as a Hickok. After I divest myself of this cache of tubes, a lowly emission tester would probably suit my guitar amp needs.

A lowly emission tester would probably suit the purpose for your sale. Assuring strong emission with little to no grid leakage and no shorts goes a long way towards making the sale. Sure, it's nice to be able to cite measured transconductance values. Regardless, you might be able to get a good emission tester like an Eico 666 or a Sencore Mighty Mite for less than a quarter the price you might have to pay to score a Hickok.

I guess it depends what you hope to get for the lot. If you've got a huge pile of tubes that aren't worth a dollar a piece, then just try to sell them in bulk at a low flat rate. It sounded like you have at least a dozen or two vintage tubes that command high prices. If you've got a tube that you think might sell for $100, it might be worth your time to test it and sell it separately (or as pair of a pair/quad).

I guess it all really boils down to the value of your time.

[DeathRex]

I have an emissions tester you could use.