OC1074 , OC1075, OC1077, OC603, OC304 Transistors - opinions?

[Guurf2]

Hi,
So i'm getting some of these 4 types of Ge transistors today,
OC1074 , OC1075, OC1077, OC603, OC304.
I wanted to know before i actually buy if they are any good for stompboxes- fuzz/trebleboost/etc. I mean, are they consistent in Hfe/Iceo? Usaly high or low gain? Usualy high or low leakage?
Sound good or not?
I know it's a general question and not an easy to answer but for example i've got 30 AC127s and theyr'e all pieces of crap... and out of my AC125s for example- some manufacturers are more leaky than the others usualy.
So, have you had any experience with these OC1074\OC1075\OC1077\OC603\OC304 (most tungsram or telefunken) ?
How do they work for you?
Thanks!

Guy.

[smallbearelec]

are they consistent in Hfe/Iceo? Usaly high or low gain? Usualy high or low leakage?
Sound good or not?
it's a general question and not an easy to answer...

I had not seen any of these numbers, and I have been buying obsolete germanium for a long time. That said, they do show up as general purpose audio devices in radiomuseum.org, so they could be possibilities.

However, the market for obsolete germanium being the opaque creature that it is, your questions are impossible to answer. The variations in gain, leakage and junction capacitance in lots of the same part are too great for any general comment to make sense. I have done my best to provide some transparency by offering a range of lots whose provenance I know and that I have sampled. Spending a bit more money to buy from me or one of my several competitors (as opposed to eBay) is your best bet for getting parts that you can be sure you will be pleased with.

i've got 30 AC127s and theyr'e all pieces of crap

If your "crappy" AC127 are low-gain/low leakage, they might well work in Darlington pairs:

http://diy.smallbearelec.com/HowTos/BreadboardRMs/BreadboardRMs.htm
http://diy.smallbearelec.com/HowTos/BreadboardGeDarlingtonFFs/BreadboardGeDarlingtonFFs.htm

Material that's high-gain but somewhat leaky can often be put to good use in Fuzzrites, FZ-1As, etc. Time to crank up the breadboard...

[anotherjim]

Bad Ge transistors can make good sounding clipping diodes. Don't throw them out.
I haven't seen OC series with those numbers, they could well be the way selected/graded parts were marked for a particular customer.

[duck_arse]

this page shows the OC603 as "AF low noise pre-amplifier", with plenty other history, but none of the other parts are mentioned. interesting, nonetheless.

https://sites.google.com/site/transistorhistory/Home/european-semiconductor-manufacturers/history-of-telefunken

the OC1077 is mentioned on this page, saying "Tungsram made germanium transistors in the Mullard OC series, but for many of them they added 1000 to the part number".

http://www.wylie.org.uk/technology/semics/Hungary/Hungary.htm

[Guurf2]

OK cool thanks,

well i couldn't avoid the thought that if these "weird" variations of Ge's only started showing up for sale now, maybe most of the good obsolete ones are just gone and the "defected" series's are starting to pop out. just an opinion i don't know really.
also - AC150? ever got to try these?