OC-Series Ge's

aziltz · July 30, 2009, 09:30:17 PM

I found some OC141s at work and went a-google'ing... I came up with this datasheet.

It lists HFE rages for the entire OC range but it also has intended usage, and I'm not sure what to make of it.

For example the "legendary" OC44 is listed as "Mixer/Oscillator", and the '71 says "Audio Amplifier". The '141s I found say "High Current, High Speed Switching", but I was hoping to use them for gain stages.

I was gonna try to use them anyway, an HFE range of 80-200.

Anyway I figured this page might be useful to some.

Scruffie · July 30, 2009, 09:36:25 PM

Yea i've also wondered about this too, I've got quite a few OC's lying around from old radios that are switching etc.

SonicVI · July 31, 2009, 01:43:52 AM

The OC139, 140, and 141 work great in fuzzes and boosters. Remember that they are NPN though.

slim_blues_boy · July 31, 2009, 06:38:30 AM

try all germanium transistors as long as they are in 'right' gain range.
but I would try all germanium transistors, even if they don't have 'right' gain just to know how they sounding.

Meanderthal · July 31, 2009, 07:54:45 AM

None of them will list fuzz pedals as their purpose, their reason for being manufactured. Not even ac128. So, don't worry about misusing them, even ones intended for switching sound great.

Scruffie · July 31, 2009, 09:18:00 AM

Quote from: Meanderthal on July 31, 2009, 07:54:45 AM
None of them will list fuzz pedals as their purpose, their reason for being manufactured. Not even ac128. So, don't worry about misusing them, even ones intended for switching sound great.

Oh yea, I doubt any transistor to have been made for an guitar pedal (except maybe re productions) I just wondered what the meanings were and if some where more suited than others, i've tried them all and they seem to each work better in different things and an explanation might get me closer to knowing why... then again, it could just be cause there germaniums and too unpredictable.

aziltz · July 31, 2009, 10:16:29 AM

Quote from: Scruffie on July 31, 2009, 09:18:00 AM
Quote from: Meanderthal on July 31, 2009, 07:54:45 AM
None of them will list fuzz pedals as their purpose, their reason for being manufactured. Not even ac128. So, don't worry about misusing them, even ones intended for switching sound great.

Oh yea, I doubt any transistor to have been made for an guitar pedal (except maybe re productions) I just wondered what the meanings were and if some where more suited than others, i've tried them all and they seem to each work better in different things and an explanation might get me closer to knowing why...

exactly... I was wondering if "Switching" would make it automatically not good for "audio" uses.

I can't wait to take these home!

petemoore · July 31, 2009, 11:08:32 AM

Gain and Leakage determine whether you have something that will be easy to work with and make Fuzz/boost Ge effects with.
Some Ge's may even treat the HF's differently than others, so it's a matter of taste or tweeks, I'm convinced one is better than the other when I've learned how to stick with a tuned Fuzz long enough to learn how to use it.
2n3904 is also a switching transistor, 'switching' is a very common term/expectation for a transistor.

aziltz · July 31, 2009, 12:33:40 PM

Going through the closet of things no one will ever use again, here's what I came away with,

10 - OC141s
10 - OC75Ns
10 - 2n280s (equivalent to OC71 I've heard)
5 - 2n281s
5 - 2n218s

looky looky

Also I found thousands of carbon comp resistors.

Toney · July 31, 2009, 12:36:17 PM

Use the force, luke...

Or in this case your ears.
If it sounds good, it's good. That's all. No rules.

SonicVI · July 31, 2009, 12:50:45 PM

I think switching just means they're desinged to be able to make a fast transistion from cut-off to saturation (full off/ full on), but you can still bias them in-between just like any transistor.

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OC-Series Ge's