Average Percentage rate on usable Ge Trannies in a batch

[greenfuzz]

Long(ish) time lurker first time caller

I was just wondering what I should be expecting when I buy a bag of Mojo fuelled, super expensive NOS Germanium Transistors? How like am I to get a full bag of magic how many do you usually bin? I am talking about those that have high leakage 500uA, low gain <25 or just plain old duff?

Also how does does high leakage affect the build ? I have readhttps://www.freestompboxes.org/viewtopic.php?f=44&t=458 Relative Importance of Gain in Fuzz Face

Thanks

[DaveKerr]

If you're buying off EBay, you run the risk of buying someone else's picked-over rejects. If your idea of mojo-fuel is Soviet-era PNPs, though, search through the related threads here for some ideas on reliable sellers and what you can expect for gain and leakage for several different models.

[Kill Switch]

I went the other way and tried some Germanium PNP TO-5 cans without any listed specs for cheap from a midwest surplus dealer. 15 and 20 cents a pop. Picked up 40. Yield was good. About 50% in fuzz face range for hfe. A few over 200. One over 300. About 90% useable overall. Tried several in a FF circuit and they sound pretty good. leakages not bad at all on most. 40ua to 120ua on most. Only 4 out of the 40 were high leakage. No idea what the specs may be for frequency but they work as fuzz makers.

[R.G.]

Back when I started with germanium transistors in effects in the 1980s, your odds were about 50-50, because all germaniums were unused and unloved, so they were whatever they were. By the time I wrote up the germanium gain/leakage tester at geofex, the odds were about 1 in 3 good based on my buys and testing before that went public. I built up quite a bone pile of leaky and low-gain devices.

Fast forward to today, when there are many thousands of genius boutiquers scouring the world for little pockets of cheap but good germanium, many of whom have been doing this scouring for years through the internet all over the world.

What are your odds of finding a glory hole that they haven't found yet? And what are the odds that the "glory hole" is actually a pile of ... um, leftovers... left by one of the professional part miners?

If you want a few to make some pedals with, go buy them from Small Bear Electronics. They're honest and do the preselection for you, having spent years doing the part-mining. Whatever their price, it will be cheaper than doing the looking for yourself.

If you want hundreds to make your own line of boutique pedals, you're going to pay for the education either in terms of prices to a knowledgeable part miner or in rejects while you learn to find, test, and sort whatever nuggets you find.

It would help to google for "geofex.com germanium".