why the heck is it...

[pinkjimiphoton]

that in some circuits, it doesn't seem to matter which way a transistor is oriented?
i've built things where you can swap the e's for the c's, and it makes almost no difference whatsoever!!

i KNOW the acid wore off a long time ago, so....why does this work like that? seems to happen in a lot of fuzzes...is it because in some circuits the transistors are being
used more as diodes to add distortion?

clueless here... i realize sometimes pinouts are different on some transistors, which is what led to this "discovery"...it shouldn't work at all, i would think.

in my fuzzface in particular, it can get REAL confusing ...i use different transistors in the winter and the summer in my fav face...
but i've noticed it seems to like upside-down trannys in some cases.

wtf?

any ideas? i've been meaning to ask about this!!

[iccaros]

if you read the data sheet a lot of transistors say you can swap them.. See J201 (NOTE: Source & Drain
are interchangeable) .. --> javascript:openreq('http://www.datasheetcatalog.org/datasheet/fairchild/J201.pdf')

if you think about it, this make sense, the transistor is made up of two types of material one sandwiched between the other.   P-N-P or N-P-N.   so the P's on either side work the same, and the N's on the other side work the same, its the Polarity on each side the determines current flow (negative to positive)

of course others can explain this better, but I will give it a good collage try..

when you apply a voltage to the P material of a NPN (not pointing in.. no negative Positive negative) transistor, and the voltage is more positive than the emitter, current flows between them, but this is a limited gate, but if the voltage on the collator is more positive than the base now and the base is more positive than the emitter current flows all the way through ?? no.. I could be wrong.. but in any case it dose not matter what side we call collector and what side we call emitter, its the same rules.

try connecting back to back diodes and place using the center as a gate..  I believe this would work.. if not someone smart will reply..

[pinkjimiphoton]

thanks for the reply!!

i thought i was crazy for a moment or three... 

i remember saying to someone to switch the orientation of a transistor and getting my head ripped off a while back.

your explanation makes sense. i didn't know you can switch 'em around, but now i think i understand in my limited way why it works out.

thanks!

[The Tone God]

And while we are at it "why the heck is it..." we cannot use more descriptive and/or accurate topic titles ? hint hint

Andrew

[CynicalMan]

Most of the JFETs we use can have their source and drain interchanged without any change in operation.

As for bipolar transistors, they do operate like a transistor with collector and emitter interchanged. However, most act with a far lower beta (current gain) than with the normal orientation. This property is called the reverse beta or reverse hfe. Modern transistors usually have very low reverse betas, but old germanium transistors usually have a fairly high reverse beta, not that much less than their forward beta. So that's why it works in the fuzz face, the transistors just act as if they have a lower current gain.

[pinkjimiphoton]

sorry andrew... 

so cynical man...you could use higher gain si trannys backwards in fuzz circuits to emulate low gain ge devices i'd imagine?

this is cool...thanks for the info.

[CynicalMan]

Not with a modern silicon transistor, the reverse beta is far too low. For most silicon transistors, the reverse beta is below 10, and it's often even below 1. You can read about the manufacturing differences here:
http://www.muzique.com/lab/reverse.htm

[pinkjimiphoton]

diggit, that would explain why ge ones work and si ones don't..

thanks for the link, going there now! 

[pinkjimiphoton]

wow...that explained it in a way even I could understand!!

printed it.

[Earthscum]

Not with a modern silicon transistor, the reverse beta is far too low. For most silicon transistors, the reverse beta is below 10, and it's often even below 1. You can read about the manufacturing differences here:
http://www.muzique.com/lab/reverse.htm

I think that's the trick for the Gemini III... gonna go pop that up for Dino. Nice read!

[pinkjimiphoton]

i just noticed your tagline, dave...

no fooling....i lost count of builds, but i have 4 milk crates full of pedals in the other room, not counting my pedalboards...

i usually try and build up at least 2-3 a week....

jimi photon: "hello, DIYstompboxes, my name is jimi, and i am cross-addicted...i am addicted to fuzz, addicted to 60/40 solder, and have PAS...pedal aquisition syndrome..."

DIYstompboxes: "welcome, jimi!"

[R O Tiree]

Much better, it sez 'ere, to get addicted to 63/37 solder

Shiny...