Mullard OC75 Identification
How does one tell that they have an original NOS Mullard OC75 vs one from someone else? Obviously, it is easy to tell a Mullard OC75 if it has "Mullard. Great Britain" printed on it. However, at any time were Mullard OC75s produced that did not have the Mullard name on it? For example, I have seen transistors for sale that are advertised as "Mullard OC75, military version" and these do not have the word Mullard on it. So, my questions are: 1. How does one tell a real Mullard OC75 from a non-Mullard OC75? 2. Were Mullard OC75s ever produced that did not have the word Mullard on it, such as military versions? 3. The first photo below shows a Mullard OC75. However, does the second photo show a Mullard OC75, possibly a military version? I think it would be good for people tinkering with vintage pedals to know when they have a real Mullard OC75 as opposed to a "copy" so hopefully we will get some definitive answers to these questions :-)

I've been wondering this myself but i came to the conclusion that if it doesn't say mullard on it assume it's not a mullard. Another question on transistors (hopefully not hijacking your thread here). What's the general consensus on buying used transistors ie. buying old circuit boards with the transistors already soldered to them? I recently bought a couple of old circuit boards with some oc76 and oc72 transistors on them and they turned out to be really good, these look like mullards but again no name on them, they are black glass with the metal case over the top. My thoughts behind buying used transistors is that they must have been selected from a big batch at the time the board was made and so be of decent quality?

I should have been more specific, when i said 'quality' i just meant low leakage and on-spec hfe. I think even then you're not guaranteed good results.