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Thought I'd pass on this info. I got the word that Ei tube factory in Serbia (former Yugoslavia) has shut down production. They've been making tubes for 50 years. They had ties with Telefunken and Dutch Philipps. While many people seemed to really like Ei tubes for thieir sonics. Ei tubes have been plagued with quality issues in recent years and factory production output became minimal. I'd venture to guess that recent skyrocketing oil prices had direct effect on this outcome. Their KT90 was a superb tube when they made it right. Unfortunately, EI KT90 started showing quality issues some time ago, but I was really hoping they would address it and start shipping this wonderful tube again. I'm really going to miss this tube.
Wow! That's huge, have you stockpiled some inventory?
I wish we could have. We do have a few hundred smaller Ei tubes left in stock but that's not nearly enough of a stockpile. Unfortunately, their production pretty much dried up for the last few months, so there has been very little to stockpile with. On a related note, Elite Golds started showing up with too much gold on their pins a while back. Their pins are simply way too thick to fit in sockets. Talk about irony, Ei is shutting down due to financial problems, and here we have Ei tubes that can't be sold because it has too much gold on it! But anyways, does anyone know of a way to safely remove at least some of the gold of off tube pins? Grinding or sanding won't work. Isn't there some electro-chemical way or some such?
A cyanide bath will disolve elemental gold. Ask a local university for help. Should be a fairly easy task.....Colin http://www.cyanidecode.org/cyanide_use.php
Wow, Cyanide? That means no DIY gold removal for me for sure! I'll ask around. Thanks, Colin!
That's why gold mines are a NASTY place to be. If you are unable to find anyone willing to help, PM me.....Colin
Would some sort of reverse electroplate set up work…John
Making an electrical connection to each pin would not be trivial. This connection would oxidize (disolve) before the gold plating. Using cyanide in a lab setting is actually pretty safe. If that scares you, look at "Aqua Regia." This scares the crap out of me.... http://jchemed.chem.wisc.edu/JCEsoft/CCA/CCA3/MAIN/AQREGIA/PAGE1.HTM
Heck, I mix concentrated HCL and HNO3 with 30% H2O2 every day to dissolve animal feed samples for mineral and metal analysis. Heat it up to 125 deg. C and cook it. It isn't that bad if you have a fume hood. H202 mixed with HCL can be nasty stuff without one. Now Hydrofluoric Acid is what makes me nervous! I triple glove with that stuff.
This is why I could not make it as an analytical chemist. I hated digestion and ash testing. I knew of one guy in grad school that had HF burns. I didn't know the full story other than he went to the hospital in much pain.....Colin