Posted by
rocket88 on
May 27, 2016; 5:34am
URL: http://guitar-fx-layouts.238.s1.nabble.com/1n34a-diodes-tp30980p31033.html
there were other markings for them, depended on who produced them. two examples i've got some with 2 black bands on one side (like 1n270s), and ones with a single green band. different production times, and different manufacturers.
even though travis already pointed out that looks can be deceiving, but a good rule of thumb is that germanium diodes will never be in DO-35 packages, small Si size. those that are and sold as Ge are always schottky diodes that are work-a-likes. those do sound very good and very similar to the Ge ones, and they're cheap as chips, but they're not Ge.
i've bought the Ge diodes from tayda before, and had some that are good and some that are way out of spec. the price is also
TOO cheap to take the risk. i do have a stock of about 1000 1n34a, 1000 1n60, and 500 1n270 diodes, the price was low because I bought them from a distributor for the manufacturer of them, and you know what some are spot on and some are out of spec with a forward voltage as high as ~0.70V. i'll bet that the ones i have are made by the same company tayda gets theirs from, but mine are more in spec then the ones that seem to be floating around. the NOS 1n34a diodes i've got have a forward voltage of ~0.50V, all of the schottky ones i've got have a forward voltage ~0.25V.
the big picture is, just like buying a Ge transistors unsorted, you have an equal chance of them all being spot on or off. just because the part number is right, doesn't mean they will fit the specs. case in point, MP38a IMHO is one of the best and most reliable gain NPN Ge transistor out there. from one seller my last batch of 200 had gains as low as 20hfe and high as 90hfe with a wide spread, and from another that i've dealt with that i just ordered 250 from the gains were all between 60hfe and 160hfe, with the bulk in the 90's. you have to know who you're dealing, what a fair price (ie not too low), which on average is $0.70 each, and someone who is reliable. i only buy from Ge parts from
RELIABLE sellers for rare obsolete parts. part of the problem is that with these, since there's a demand by a large group, the prices go up, stock goes down, so the number of fakes go up, and what's left isn't always the best parts as far as stock goes.
like beaker, i highly suggest the same diodes he does, and from the same seller on ebay. for some of the parts we use it's not really worth the hassle of wading through parts that may or may not be in spec, especially to save a buck when there are parts that available for really good prices still, that do as good a job if not better. with the D9 diodes each model has a slightly different tone and are cheap as chips, so you can get a nice stock of each for way less then trying to get the same amount of the the big 3 Ge diodes (1n34a, 1n270, 1n60). shit i usually get D9's, D310/D311/D312, and D18 diodes in packages of 500 or more of each kind and spend ~$100 for all for it all. also, there's a discussion about the topic of real and fake Ge diodes and testing,
here. i forgot about the thread so i didn't post the testing results of diodes since the last post.
side note about FETs from tayda. i've bought a bunch over the years from them and so far so good. i've yet to get any that had been out of spec. but, due to what's happened with the FETs that are circulating, once i run out i'm going SMD with adapter boards. much more reliable, and basically the same cost that i paid for all the through-hole FETs i have.