Rolled some 12ax7's recently...


Hi All,
I went through my supply of 12ax7's recently and found some goodies.
I recently compared Bugle Boys to Telefunkens in the phono stage of my pre-amp. Interesting (to me, at least). I found the Telefunkens to be nice sounding; very clean and clear, very nice detail, over all a very nice sounding tube. The Bugle Boys, however, were magical! WOW! Timbre was so much more apparent. The soundstage depth and width increased; especially the depth. The music seemed to come alive and glow. It was much more captivating.
I found such a dramatic difference between two high quality tubes very interesting.
I have yet to try 10m's, and 70's Mullards that I found. I will report when I do...
By the way, NOS Sylvania's sound nice in the line-level stage. All tubes reported are vintage NOS. I match them with my tube tester. And, I do not change the volume setting between tube brands tested.
Any comments are more than welcomed! I appreciate any information on your experiences with 12ax7's. The price of some of these NOS is incredible; I am glad to have these nice examples in my collection!
Cheers.
bicycle_man
Thanks Nsgarch for watching out for me. I should have put a "just kidding" type statement after my first paragraph above. Sorry, my sense of humor can be pretty bad or twisted.

I have read articles on the Internet in my research about the counterfeits of the highly valued "NOS" tubes, and one of the first things they mention to look out for is labels that are tenacious and don't wash off.

Actually, as an aside, the counterfeits make me wonder about re-issues. Are they really built to spec of the original tubes, and with the same quality of workmanship? The burning question is, do they sound as good? Anyone have experience with them in comparison to the originals?

From the very first moment that I started cleaning my NOS tubes, I noticed how easily the labels came off. The labels were practically rubbing off in my latex-gloved fingers. And with isopropanol, they came off immediately (the labels, not my fingers). I immediately broke out my tube tester and Sharpie-brand marker, and numbered, tested and cataloged my tubes before cleaning the rest. I matched the tube number to the tube brand and measured specs. I am so happy I did that because now, years later, I can still identify tubes and match them.

Thanks for the tip about Herleen Holland, too. I will look out for them. I like the BB's so much that I am very curious to see if the other Amperex's sound as nice.

Thanks again for watching out for me so that I don't get ripped off -- there are many things I am naive about and it is great when decent people speak up!
B-man, we were all beginners once, and although people have to have their own learning experiences, it doesn't hurt to ive folks a little heads up.

As for current ('reissues') vs. NOS (honest people now call them ANOS = almost new old stock = slightly used old stock ;-) Honestly, slightly used is a better bet than brand new old stock because at least the slightly used are proven working. If I were buying expensive BRAND NEW old stock tubes, I'd make a deposit but then insist the seller
test and burn-in the tubes for a few hours before shipping them to me ;-)

As for their sound, the current issues aren't bad, and I'm sure they will slowly get better. The brands bought by the American fellow who owns New Sensor in russia are: Sovetek, Genalex Gold Lion, Electro Harmonix, Svetlana, Mullard, Tung Sol, and a few other I forgot. None of them are like the originals (internally) although some are built very substantially.

The real difference between the old and new is metalurgy. The old-timers who experimented for years and years cooking up new (secret and jealously guarded) plate coatings had no one to pass the secrets to when ss came along. So the craft died with them. They succeeded in achieving very high plate current at rated voltages that tubemakers today can only hope they'll get to one day.

As an example, a typical NOS Genalex GEC or Gold Lion had transconductance values (when new) of 10,000 umhos or more (that's the measure of a tube's gain). Today's best KT-88's, the Genalex or the Shuguang/Penta-Labs (the Penta is an exact copy of NOS tube) when they are brand new are 7000 to 7500. I have some USED NOS Genalex theat are 9000! So it's not so stupid to buy he older tubes and some of them have a sparkle to them than so far no current tubes can duplicate. Anyway that's the basic story. There's tons of history and lore available today at the click of a mouse.
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Yes, it does appear that many older tube varieties have very fragile printing on them. My telefunken ECC83/12AX7s barely have any markings left, just from handling. I am fairly careful handling the ECC803S which were never used (cam in very nice looking boxes, though the cardboard has become somewhat fragile). My Bugle Boys also have somewhat fragile printing.

Because of all of this discussion, I did something I rarely do (being quite lazy), which is to switch out the ECC803S and replace them with the ECC83. Where my memory was that the ECC83 was more "muddled" sounding, that turned out to not exactly be the case. The ECC83 is not really more muddled or lacking in clarity, it is more the case of transients (initial attack of the note) being softened, as compared to the ECC803S. I still prefer the ECC803S, but again, the price differential is striking.

I should also mention that, in another friend's system, the Bugle Boys sounded terrific in the phono stage of a Hovland preamp -- so much more lively than the stock tube that came with the preamp.
Larry, one day I just said, "this really sucks!" and I got some Q-Tips, gathered a few old European tubes that had almost no printing left, and set out to try every solvent I could think of to see if anything would spare the printing. Naphtha was IT. And no surprise really -- that's the only solvent dry cleaners will use on your clothes!

I should have noted that even the moisture in some peoples' skin can take off the printing, so it's best to handle those with really fragile (almost gone) labels with a clean cotton cloth or latex gloves before and after cleaning.
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