What to do with PN2222

modsquad · February 23, 2007, 11:06:22 AM

I just scored a handfull (30 or so) PN2222s for about $2. I know these are generic op amps. Was just currious on what ideas you guys had on uses. Also any experience with them as far noise, performance, etc. I have to find something to do with them.

Stan

Meanderthal · February 23, 2007, 11:28:41 AM

QuoteI know these are generic op amps

Wtf? Obviously, they're not ICs let alone opamps.

They're npn transistors. Rather low gain for silicon. Use them where you need a lowish gain npn silicon transistor.

modsquad · February 23, 2007, 11:39:33 AM

Doh...

I knew that, I had OP Amp on the brain. I meant its a general purpose amplifier transister. I'm an idiot that's why I am curious on the performance of them.

Stan

Meanderthal · February 23, 2007, 11:47:01 AM

Heh... from one idiot to another, no big deal...

Try them in circuits calling for 3904, or sort them for gain and build a si npn FF...
They're known to be a bit noisy...
I don't think the plastic case ones are going to work as a negistor.

jrc4558 · February 23, 2007, 12:39:38 PM

LoFo MoFo!!! http://www.geocities.com/tpe123/folkurban/fuzz/lofomofo.gif

Steben · February 23, 2007, 01:12:34 PM

Fuzz (Face) it!

Ronsonic · February 23, 2007, 07:18:13 PM

Think "2N2222" about the most generic transistor on earth. They are as general purpose as it it possible to get.

Build anything that doesn't need anything special.

Ron

Shepherd · February 23, 2007, 08:27:27 PM

People seem to love 'em in the Maestro Filter/Sample & Hold...as the noise transistor. With 30 you should be able to find a real good one.

markm · February 23, 2007, 09:26:07 PM

There's a time and a place for everything and some circuits sound great to me with 2222's.
But then again, I like 741 op amps!

jlullo · February 23, 2007, 09:50:22 PM

Quote from: markm on February 23, 2007, 09:26:07 PM
There's a time and a place for everything and some circuits sound great to me with 2222's.
But then again, I like 741 op amps!

i second that. i have the 2n3904's in my ts replaced with the 2n2222 metal can version. i think they sound MUCH better

Gilles C · February 23, 2007, 11:27:52 PM

I always loved metal cans 2N2222... and 741s...

But I'm old abd vintage, that's why I line vintage stuff that still works well...

zachomega · February 24, 2007, 12:53:03 AM

Perhaps this is the place to ask a quick question and semi-hijack the thread. In cleaning I came across an unusual "transistor" with 8 legs and the number 741BE on it. This is indeed an IC in a metal transistor casing?
Thanks guys,
-Zach Omega

Ronsonic · February 24, 2007, 01:25:59 AM

They made a lot of ICs in that type of can with a tab on it. If it says 741, I'd believe it (unless it's part of a date code:) and use it in something. You KNOW it's got more mojo than the usual DIP package.

And, it might sound just great.

Ron

zachomega · February 24, 2007, 01:44:04 AM

Perhaps...I'll never find out though...I'm going to toss it into a loose IC lot I will be selling shortly. Just wanted to make sure it wasn't something else first.

-Zach Omega

Quote from: Ronsonic on February 24, 2007, 01:25:59 AM

They made a lot of ICs in that type of can with a tab on it. If it says 741, I'd believe it (unless it's part of a date code:) and use it in something. You KNOW it's got more mojo than the usual DIP package.

And, it might sound just great.

Ron

Dragonfly · February 24, 2007, 03:00:04 PM

People seem to be forgetting that he's asking about PN2222 transistors, not 2N2222. A bit different beasts. Sure, you can sometimes use them interchangeably, but not always. The PN2222 wont work in things like Doug Deepers "Garage Fuzz", for instance. The PN2222 is a nice general purpose tranny, but any circuit that calls "specifically" for a 2N2222 probably wont work correctly with a PN2222.

AC

Ronsonic · February 24, 2007, 06:11:15 PM

If I am mistaken, beat me with heatshrink!

Hey, that's just a figure of speach. Lemme look 'em up.....

Fairchild thinks they're the same: http://www.fairchildsemi.com/ds/PN/PN2222.pdf

And the other datasheets look enough alike to fool me: http://www.eecs.harvard.edu/cs141/resources/2N2222.pdf

I won't argue if you find them not working the same in some of the crazy crap we work with.

Ron

Dragonfly · February 24, 2007, 11:16:10 PM

Quote from: Ronsonic on February 24, 2007, 06:11:15 PM
If I am mistaken, beat me with heatshrink!

Hey, that's just a figure of speach. Lemme look 'em up.....

Fairchild thinks they're the same: http://www.fairchildsemi.com/ds/PN/PN2222.pdf

And the other datasheets look enough alike to fool me: http://www.eecs.harvard.edu/cs141/resources/2N2222.pdf

I won't argue if you find them not working the same in some of the crazy crap we work with.

Ron

Yeah, most companies think theyre the same. The 2N2222 is a metal can, the PN2222 plastic ...they sound different, and the PN wont work as a negistor. Its a common mistake...people try to build certain circuits that cal for the 2N2222, and the sub the PN and wonder why it doesnt work right.

AC

col · February 25, 2007, 02:21:02 PM

They don't look or sound the same is some circuits and neither do metal can 2N2222A transistors as I've tried them. I only managed to get 2 2N2222 trannies from my local shop and I wish I'd got some more while they had them!!
Having said that the plastic PN2222 do sound good in some circuits and are useful as a trial if you socket your stuff as they have the common CBE pinout.
No matter what people say regarding Hfe and interchangeable transistors, some DO sound different, and I can't believe it's just my ears. Some transistors seem to produce clearer bass or treble and have different switching capabilities even if the Hfe is nominally the same.
Perhaps I'm just mad? Can someone explain?

News:

What to do with PN2222