lesson learned!!!!!!!!! different orientations of 5089 from same bag!!!

Started by pinkjimiphoton, January 28, 2019, 02:44:41 PM

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pinkjimiphoton

guys,
always check the pinouts on your transistors before installing them.

i built a new fuzz. uses 5089's. i pulled two out of the bag, stuffed 'em in, and spent 2 hours debugging the damn circuit. couldn't figure out what was wrong. i had soldered in the transistors, as i had breadboarded it and new the circuit was good, right?

well, turns out that 5089's have TWO different pinouts possible... ebc or cbe.
as it turned out, both types were in the same damn bag. i dunno if tayda did it, or if i did it combining "leftovers"...

but the whole time i didn't realize the pinout was wrong. i pulled the q's and reinstalled them, after flipping 180 degrees i dunno how many times chasing the damn dragon to the point they opened up and got hissy and ugly in a really bad way.

so i said screw it, and added sockets <i hate sockets cuz they fail too easy in live environments.... the first fuzz i sent dick wagner arrived DOA cuz the damn q fell out in transit> and started plugging in random q's before deciding to use the ones on the breadboard, which is when i noticed they were clocked opposite <the breadboarded version had a separate board the first stage was already built, and the second stage was added on the bb>
i was like... aww, @#$%, did i just waste all this time for nothing???

checked with my little tester... sure enough, opposite pinouts. plugged 'em back in and the fuzz came to life.

so... IF you're having problems with transistors that just won't make sense, and won't bias correctly or seem like they're in backwards, even from the same damn sack, odds are the same may have happened to you.
i'm gonna revisit some earlier "doa" builds with more than one q and see if this is indeed what happened.

maybe it was a mistake on tayda's part, maybe on mine, but man, i am gonna check every freekin transistor FIRST from now on before i solder it in.

anybody else ever have this happen to them?

btw... the "noisy" transistors were fine, once they were alligned opposite each other.

made my head hurt. a quick 1 hour build turned into another 4 am thing.

RG and Mark and so many others have said it for years... look up your pinouts!!
but....

make sure that all the transistors in your bag of parts use the same orientation, never "assume" they'll all be the same.

thanks for listening to me vent ;)
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Paul Marossy

That sounds suspicious.... I've never seen a 2N5089 data sheet that shows two different pin outs.

pinkjimiphoton

me either. but both transistors were from the same bag, have the same markings, and came from the same vendor.
in fact, the bag is a mix of the two.
perhaps rebranded counterfeit?
beats me, all i know is that the pinouts are opposite.
i usually am a germanium guy, and when i build circuits, i use specific si's in most of them, so i don't buy a lot of 5089's cuz the gain is higher than i like to work with with fuzzes.
its weird, but it happened. i'll take pics of the meter and post them. my tester and my multimeter both read the same pinouts, so i don't think either is likely broken... and the ONLY way to get the circuit to fire is with one in backwards.
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"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
~Jack Darr

Mark Hammer

Like I keep saying, you would think that there aren't that many different pinouts for three little pins.  Somehow, there are over 800 of them  I can't explain how it happens, it just does.

pinkjimiphoton

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"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
~Jack Darr

tekhna

I had some (seemingly) wretchedly out of spec 2n5088s from Tayda recently, wonder if it's related. Couldn't get 'em to bias for the life of me.

Paul Marossy

Quote from: pinkjimiphoton on January 28, 2019, 02:57:04 PM
but from the same part #, bag, and batch?

how wack is that????

I'm thinking fakes... like a re-labeled something else with a different pin out.

Rob Strand

I'm with Paul, sounds sus.   Especially if they are marked the same.

As a cross-check there's another way to check E and C is:  The voltage VBE  is higher than VBC so the higher measurement will identify the emitter.   You need to do the measurement accurately because the numbers are close so don't touch the probes or transistor leads with your fingers.  (That assumes the part isn't fried of course.)

[There's another way where you measure the VBE breakdown (5 to 10V) using a 15V supply and a 1M or so resistor.  I don't recommend it if you are going to use the transistor afterwards for audio.  OK if you are going to bin it.]
Send:     . .- .-. - .... / - --- / --. --- .-. -
According to the water analogy of electricity, transistor leakage is caused by holes.

pinkjimiphoton

ok moron alert here. just had a chance to check, 4 am i do some dumb things.
turns out the orientation is the same, BUT in this particular circuit the transistor is reverse beta'd. i see ya rolling your eyes, but in this circuit it works, and sounds great.
i didn't realize i'd built the circuit around that being backwards, when i couldn't get it to bias i flipped it and it worked great so i assumed i had the pinout wrong.
my sincere apologies!
i've played with reverse leaky ge, but a 5089?
circuit here if ya wanna see it, just remember til i fix it q2 is shown backwards

https://www.diystompboxes.com/smfforum/index.php?topic=121816.0
  • SUPPORTER
"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!
"try whacking the bejesus outta it and see if it works again"....
~Jack Darr