Vintage 12AU7 + other direct drop in variant/equivalents Introduction
On-line sales only please
No cash sales or pick ups
Orders are pre-payable by emt to:
[email protected]
For local GTA Finch+Dufferin area pre-paid emt pick ups orders
Due to Covid we cannot safely accept any cash nor should you....!
Currently we can only offer pre paid safe distance pick ups
We'll arrange to safely meet you at your car when parked here
Then we'll safe distance extend dropping off at your passenger side window!
Thank you
Many 12AU7 + other direct drop in mil. spec. equivalents and variants:
12AU7 / 5814 / 5963 / 6189 / 6680
from
$20.00/single tube
$50.00/matched pairs
You don't spend huge on a 12AU7...
Even a $20.00 vintage NOS tube in can be a really great improvement
I'm going to tell you a few secrets about tube rolling. They'll save some of you a heap of money, let you have a lot more fun (without missing any meals), and undoubtedly piss off a few people. What I'm going to tell you are really simple historical and technical facts about tubes. (They aren't really secrets - it's just that your average discussion about tube rolling these days has an eery resemblance to listening to a couple of kindergarten kids discussing what brand of chickens work better for voodoo spells. And, yes, all the smarmy insinuations you can read into that metaphor were intentional.
If you want to check any or all of what I'm telling you, then go on eBay and buy some actual technical information manuals about tubes. You can buy a vintage copy of the RCA Receiving Tube Manual, or the Sylvania equivalent. That's the book, written by the folks who invented and manufactured most of those tubes, which explains how they work, and what parameters are really important, and shows engineers how to design products that use them. Odds are the guys who wrote it know way more about their tubes than the guy trying to get you to pay $100 for a NOS specimen of one that sold for $2.29 at your local hardware store some fifty years ago. If you search carefully, you can find all sorts of cool resources, including design and production manuals, which contain real information about tubes - instead of folklore.
Fact #1: Tubes were intended to be identical and interchangeable. The reason you have designations like "12AU7" is because you are supposed to be able to plug any 12AU7 into any socket labelled "12AU7". Back when tubes were current technology they really were considered interchangeable - sort of like 60 watt light bulbs. You asked for "a 12AU7" and the guy gave you whichever brand he happened to have. It you asked for a particular brand, it was probably because you wanted the color of the writing, and the cute little picture, to match the other ones in your unit - nobody much imagined that they sounded different. There were some differences, and some manufacturers claimed slightly better specs, but the differences were pretty slight - and maybe not even true. The main specifications are spelled out by that designation number. A 12AU7 has a certain gain in a given circuit; if you want more gain you don't look for a 12AU7 that's out of spec - you use a 12AX7; if you want less gain, then you go to a 12AT7. Just like anything else, each manufacturer had some claim to being better - brand xx said they were a dB quieter; brand yy said they were less sensitive to vibration - but most of the differences were very small, and had very little to do with sound quality. (For example, by fiddling with the shape and size of the coating particles on the cathode, you can slightly alter the character of the hiss that the tube produces as background noise - which you shouldn't be able to hear anyway. Whole white papers have been written about which shape of particle can reduce the hiss by one or two dB.... but we are talking one or two dB here....) And, yes, some premium brands cost more - for real or perceived improvements. A cheap RCA 12AU7 was probably $25.00, while an "expensive premium import" Telefunken cost double or more!
Fact #2: The actual differences between tubes, where they actually exist at all, are limited to a few simple electrical characteristics. And, while a really good design would be totally immune to these slight variations, different tubes may indeed sound noticeably different in certain circuits. The characteristics of the cathode coating can affect life expectancy, and have some slight effect on how much hiss there is and precisely what it sounds like. The spacing between the electrodes inside the tube affects the capacitance between them, which can affect the frequency response of that tube - in some circuits. The geometry of the electrodes could result in slightly better linearity - which means better distortion numbers (although very few manufacturers claimed anything significant there). Better support for the electrodes can reduce microphonics (so you're less likely to hear a twanging noise in your speakers if you tap on your preamp tubes). Remember, though, that the important electrical characteristics are pretty well spelled out for a 12AU7, so no 12AU7 can be very far from the spec and still work in 12AU7 circuits. if it was too different - even better - then it wouldn't be a 12AU7 any more.
Fact #3: Most if not all of the differences you hear between tubes are caused by slight differences in interelectrode capacitance and gain interacting with elements of the specific circuit in which the tube is used to produce slight variations in frequency response. The gain and capacitance interact with the rest of the circuit to produce slight variations in frequency response and distortion - and the variations in frequency response are most of what you hear as "warmer" of "smoother".
Now... HERE'S THE BIG SECRET.....
In general, there are almost always no such things as "better sounding tubes". HOWEVER, THERE MAY BE CERTAIN BRANDS OR STYLES OF A GIVEN TUBE THAT SOUND BETTER - TO YOUR PERSONAL TASTES - IN A CERTAIN SPECIFIC PIECE OF EQUIPMENT.
Now, think about that one for a while......
That tube they're trying to get you to pay $150 for isn't any better than one you can buy on eBay for $15.00 (But it might sound better to certain people, when you use it in a specific model of preamp or headphone amp.) My point here is that it ISN'T the tube that's better; it just happens to work a tiny bit better in a certain product. Now, here's where you can save that money I promised. THAT $150 TUBE THAT SUPPOSEDLY SOUNDS WONDERFUL IN THE REVIEWER'S MODEL 1 HEADPHONE AMP JUST MIGHT SOUND LIKE CRAP IN YOUR MODEL 2 AMP, AND THE $5 ONE THAT SOUNDS LIKE CRAP IN HIS MIGHT SOUND WONDERFUL IN YOURS. This is because the whole idea that certain tubes are wondrously better sounding than others is a silly myth. The reality is that the slight differences between different brands and styles of tubes interact with the slight differences in tube circuits to produce slightly different results. Whether a certain brand or style of tube sounds better in a certain amp or preamp is actually pure dumb luck.
So, unless your equipment is exactly the same as the reviewer owns, and you know for a fact that you personally like the same things he does - or you really trust his judgment - save your money. Instead of spending $50 or $100 for a tube that cost an extra buck when it was new, go on eBay (or to your local tube supplier) and buy a whole handful of different tubes... and listen to them in YOUR equipment... and decide for yourself which one sounds best with YOUR equipment. (The one he's selling for $150 is NOT "better" than the $25.00 one; it just sounds better TO HIM - IN HIS PARTICULAR EQUIPMENT.) If you really like tubes, then finding out for yourself should be half the fun. If not, then, by all means, pay someone else a lot of money to do it for you.
Odds are finding a treasure for yourself will make you a lot happier than finding a $150 lump of coal the hard way.
In fact, even if you trust that seller, and he does have the same amp you do, and you're pretty sure that his $150 tube will actually sound good in your amp, wouldn't it still be more fun to find a real treasure in a $25.00 - $50.00 range of tubes than it would be to pay full price? Anybody can find a really nice diamond at Tiffany's for $50,000 - but where's the fun in that - even if you can afford it?
Incidentally, 12AU7 was one of the most common and most popular tubes EVER. (They also happen to perform very well.) You can find a huge selection of NOS ones for sale. You can also buy new ones, if you avoid falling into the "ridiculously overpriced rare vintage variations trap, you can have a lot of fun with them for a not unreasonable amount of cash. (In fact, if you have a few friends who can also use them, buy a dozen sets cheap and trade/pass 'em around... and don't be too surprised if everyone finds a different treasure in the pile!
