Gold pin tube : does it really matters ?

[i2k92]

I'm plan to build my first tube project (BCF buffer). So I decided between 12BH7 or 6CG7. I will use EHX brand as they're easy to get. Now i have to decide between standard and gold pin (about 50% more expensive).

I know that the price different is not significant if I only use 2 tubes, but could somebody enlight me what kind of difference the gold pins bring ?

thanks in advance..

[SY]

About 50% more markup for the seller.

[Speedskater]

Are the socket connectors gold plated?
A decade ago, PC computers had a lot of problems with gold plated memory cards in un-plated sockets.

[Johnny2Bad]

Does it really harm?

I can't remember the details about the gold/non-gold computer card thingy, but I seem to recall the non-gold connectors were substandard to begin with, but (of course) cheap. I also remember the short answer ... use gold on both, which is what they do now.

I don't expect your pin sockets for tubes to be so bad that you would find an incompatibility.

Glossing over a few details, in the interest of brevity, gold doesn't oxidize, so it's like having bare metal in perfect condition, forever, as your conducting surface. Works best if both contacts are the same material, though.

Silver, which does oxidize, is also used because the silver oxide is still a decent conductor, so it's not absolutely necessary to avoid oxidization. Copper oxide is a poor conductor, while soldering covers the conducting elements so it won't oxidize; oxidization generally happens in electronics with exposure to oxygen in air.

Having said all that, on principle, I would probably not buy the gold pin tubes, since they are quite obviously ... somewhere along the line ... ripping you or the supplier off. Gold plating is so thin there isn't much actual gold there (a property of gold is it can be reduced to vanishingly low thicknesses because it is so malleable and doesn't work-harden; with electro-plating, which is what is on that tube's pins, you can go an order of magnitude thinner yet).

So, although it's not perfectly correct to say there's no gold on those gold pins, it would be correct if you ignored any amount of gold that was worth, by weight, less than 1 red copper cent.

A factory could churn out a whole lotta tubes ... not sure of the number without doing some checking but it might even be a million of 'em, or multiple millions even ... with one ounce of gold (about $2000 worth).

Electroplating is not a difficult process and pretty much every electronics part is plated with something, typically multiple passes of differing materials. So, it's a routine process for the factory.

Reality check: a booklet of gold leaf, which is real gold hammered thin, but definitely much thicker than what's on these pins, 25 sheets 5.5x5.5" a sheet (or enough to cover an area roughly 5" wide and 10 feet long) is about $5. Today. Retail.

You could probably set up a quick and easy electroplating setup in your home, and gold coat the pins yourself, at very little cost. Back in the day, when I was doing photography, I had a thingy that recovered silver from developing chemicals, battery powered, cost me like $10. Same principle.

[Johnny2Bad]

Sorry, the Gold Leaf info is wrong (seems that is fake gold leaf for $5).
24K Gold Leaf 3.125x3.125" 25 sheets is actually $45 retail. Covers an area roughly 3 inches wide and 6 feet long. Doesn't really change anything in my post but in the interest of accuracy there you go.

Also:
" ... Soldering requirements are best achieved when gold electroplating coatings range between 0.00005 and 0.0001 inch (50 and 100 micro inches) thickness. ..."

[indianajo]

I've got a reverb application where the signal that comes back from the spring is about 20 mv. Most of the time never makes it into the tube to get amped. Right after you shake it it does- for about twenty minutes. I've erased the tube pins, I've poked around in the socket with a pick, no help. Received a lot of scorn for not replacing the tube socket, but Hammond had a really sophisticated star grounding arrangement connected to a tube socket ring, and I destroyed that pulling it off. Tried to make another ring, so I could install the gold socket I bought, the punch came in .895" instead of .875" (non-greenlea punch, greenleas 7/8 punch are all .895" advertised). So, it is just easier to solder in an op amp- have one I am playing with now.
Someone suggested a 100V plate max solder pin tube, but it was $29 each last time anybody in this country had any. Wouldn't be as linear as a real UK EF86 anyway. Neither are the substitute "EF86"'s. Which are not gold anyway.
Dry circuits require gold- that is why old "LSI" organs are such a waste of time. LSI circuits are dry, (low current and low voltage) so the keys & tabs stop working eventually if not precious metal plated. Hammond organs wail on after 50-80 years because the coil pickups produce a medium sized oxide burning current. Don't know how radio circuits ever worked at the front end, radios were all tin plated.

[i2k92]

Thank you guys. It seems that gold pin is not necessary other than increased price. If that is so important why don't somebody come out with gold pin opamps/mosfet, etc. And I haven't seen any NOS tubes with gold pins. So I'll go with normal tubes.

[DF96]

A few NOS special quality valves did have gold pins, but this was probably thicker than modern gold ones. E88CC is one example? Nowadays it is mainly cosmetic, and will probably be scraped off by the valve socket.

[djQUAN]

Originally Posted by i2k92

If that is so important why don't somebody come out with gold pin opamps/mosfet, etc.

There are semiconductors in ceramic/hermetic package with pins (or even entire packages) gold plated. Used for high reliability applications. Definitely not cheap.

http://www.electricstuff.co.uk/milboards.html

[yangbaibing]

I think gold pin is not necessary.Because the tube has more distortion than the pins.In addition,gold pin was used in computer card just because it's reliability.