OC44 values/measurements

[rangermaster]

Hi there.

I've got some old NOS original OC44 and OC71 transistors at home that i want to use to build some Rangemaster clones.

However.. i want to test them to check if they are still ok. I'm not really familiar with how to do this and what should be the right value/measurements.

Can someone please help me how to do this ?

Thanks!

[cab42]

As always, check geofex 

http://www.geofex.com/article_folders/ffselect.htm

I used this method for my germaniums (CV7112)

Edit: You can also just plug them in and try them. If they sound good, they are good! I don't have any idea of the gain of the tranny in my RM, but it sounds great. I built it before I tested my germaniums. I just tried a few and picked the one I liked best.

[rangermaster]

Thanks for the link. Did not found that already.

Do you also know if there are sound differences between the new and old OC44's ?

I have a couple of old OC44 here and got some new 'OC44K Tung' in order.

[garcho]

Transistors don't have a sound, circuits do. Old Ge transistors have attributes that are difficult to nail down by model number. That's why people have come up with tests, like RG at Geofex. Two transistors of the exact same model might end up making two very different sounding pedals. I'd worry more about who/where I'm buying germanium devices and less about specific models. Reputable sellers will sell you something useful, eBay pirates will sell you anything labeled Ge, regardless of usefulness relevant to pedal building, just to cash in on germanium mania.

[rangermaster]

Ok thanks. That clears thi gs up.

Normally u don't buy new 'old' transistors. I buy old old radio's and get them from there. That way you have the old germanium transistors.

[garcho]

That way you have the old germanium transistors.

You are safe to assume, in guitar pedal audio world, there are only old germanium transistors.

[rangermaster]

Ok little confusing. Because i got some newer metal can's oc44 here.

See pics:
https://www.dropbox.com/s/i5mxfjqfxc6qly5/20210128_173736.jpg?dl=0

https://www.dropbox.com/s/q619uxlw9jzkzlz/20210128_173532.jpg?dl=0


So there should not be a difference in Black glass vs Metal can ?

[garcho]

Ah, I get it now, by "new" you mean from the `60s? Could it be more glass = military spec, can = hope for the best? Sorry, I thought you meant new production, my bad, sorry to derail.

[Big Monk]

Ah, I get it now, by "new" you mean from the `60s? Could it be more glass = military spec, can = hope for the best? Sorry, I thought you meant new production, my bad, sorry to derail.