Re: Valuable 12AX7!


Ahhh, a topic that I'm well versed in. I'm an "audio nut", but am totally not into $100 cable, stones, magic dots, etc. I'm into the DIY tubes and speakers end of it. While there IS a lot of hype, bullsh*t, and stupidity in high end audio, there is also a lot of truth.

Capacitors, wire, resistors, tubes, transformers, ALL of it makes a difference beyond what one can measure with a scope or distortion meter. I am a skeptic, but personally witnessed the differences between half a dozen .1uF/630V coupling caps in an amp. It is subtle, but there. Ditto for tubes and wire. Speaker cables have a lot more going on than just resistance per foot. There are interactions between the wire strands, the insulation, the braid geometry (if any). Inductance and capacitance come into play and how that interacts with the output impedance of the amp.

However, I STILL won't pay these ridiculous sums for stuff making seemingly amazing claims. My speaker cable is made from CAT 5 network cable, costing me a total of $40 for the pair. They smoke some $250 cables I had (I didn't pay that for them).

Anyway, regarding Telefunken. Telefunken tubes command a high price simply because they were the finest quality tubes produced by anyone, ever. Truly the Mercedes of the tube world. Tele 12AX7's were the quietest, lowest distortion, and longest lasting tube out there (100,000 hours is a typical lifetime). I've got several pairs of smoothplates (borrowed out of my Tek 535A) and some from an old Dynaco amp, and they do indeed sound very nice. I've compared them with current production JJ/Tesla 12AX7's and find them better, but not enough to spend $100 each. I'll use the JJ's at $7 each and be happy.

I get the biggest kick out of homebrew audio by building something that uses a forgotten $5 tube (the 1625) that will smoke most commercial gear costing 10x as much.

Come see:

Chris wrote:

The vacuum tube audio guys have gone absolutely "stupid" over this sort of
thing. �This is the same group that will pay $100 per foot for special
oxygen-free speaker cable, $50 for special medical grade 120V wall
receptacles, $75 for a bloody "rock" that sits on top of their amplifier to
stop electromagnetic radiation from "interfering with the music flow in
their cables" (that one is called a Shakti Stone - it should be Shaft-ye
Stone). You or I will pay 50 cents or a buck for good quality cap for use
in an RF circuit - these guys have been duped into paying 5 and 10 bucks
for the same thing because the cap has special musical qualities.

I agree that you can make some pretty good money from these guys by selling
Tek quality tubes (Telefunkens especially, but also Philips and Mullards
too). �Bear in mind that you'll be competing with this same crowd when you
discover that you need a good quality 12AX7 to make something work well,
and that you previously sold all yours to them. �I'd hang-on to a few.

Having said all that - I admit that I sold a pair of used VT-52's (military
type 45's) for $300 US - $450 Canadian - to the audio guys on eBay. �The
VT-52's were in a large box containing 500 used tubes and I paid $15 for
the whole box. �I'm ashamed - but happy.


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