changing a NPN to PNP FuzzFace

[carboncomp]

I would like to change this NPN to a PNP FuzzFace

http://www.beavisaudio.com/bboard/projects/bbp_FuzzFace_Rev1_1.pdf

Do I just need to switch the polarity of the Electro Caps, and the flip GND and +9V rails? (as when I do this I just get a FAAAAAAAARRRRRRRRRRRTTTTTTT sound)??

What am I missing

[pinkjimiphoton]

hey dude

yep, just reverse the 2.2u and 22u caps.

you're gonna want to also make sure you've got the transistors reversed as well for the pnp version...swap the emitters for the collectors. backwards will make t REALLY farty.

a 10k pot instead of the 8.2k resistor will help ...  most folks seemto think 4.5v is good, i wouldset it so you can control the distortion smoothly from the guitar.

[LucifersTrip]

I would like to change this NPN to a PNP FuzzFace

Do I just need to switch the polarity of the Electro Caps, and the flip GND and +9V rails? (as when I do this I just get a FAAAAAAAARRRRRRRRRRRTTTTTTT sound)??

yes, flip the polarity of the electro caps and flip the battery


@pinkjimiphoton

you're gonna want to also make sure you've got the transistors reversed as well

make sure you've got the transistors reversed

[pinkjimiphoton]

yah, i mean make sure the trannys aren't backwards...like with the emitter on the bottom when it should be on the top....



the pinout between an npn and pnp are opposite. if you put pnp's (especially if ge) backwards, all ya get is farty blatty noise (if that, even)

don't ask me why i know this...   

[LucifersTrip]

yah, i mean make sure the trannys aren't backwards..

had me scared there for a minute...

the pinout between an npn and pnp are opposite.

opposite???  starting to get me scared again...

When you change from NPN to PNP, the EBC of the PNP goes exactly where the EBC of the NPN was.

[carboncomp]

Thanks guys, dont know what the farting sound was about, hooked up jacks so it was not going though my Beavis Board and it works fine flipping the caps

[Barcode80]

yah, i mean make sure the trannys aren't backwards..

had me scared there for a minute...

the pinout between an npn and pnp are opposite.

opposite???  starting to get me scared again...

When you change from NPN to PNP, the EBC of the PNP goes exactly where the EBC of the NPN was.

what he is saying is that yes, EBC all go in the same place circuit-wise, but most germanium pnp transistors have their pinouts flipped from modern NPN transistors. so you usually have to flip the transistor 180 degrees from whatever layout you are using.

[LucifersTrip]

yah, i mean make sure the trannys aren't backwards..

had me scared there for a minute...

the pinout between an npn and pnp are opposite.

opposite???  starting to get me scared again...

When you change from NPN to PNP, the EBC of the PNP goes exactly where the EBC of the NPN was.

what he is saying is that yes, EBC all go in the same place circuit-wise, but most germanium pnp transistors have their pinouts flipped from modern NPN transistors. so you usually have to flip the transistor 180 degrees from whatever layout you are using.

i can't see how that makes any sense...flipped from what?    there is no difference between  ebc and cbe. it just depends on which side you look at it from.  the only thing you have to worry about is with some transistors the pinout is bce or ecb...again, same thing

further, this had nothing to do with germanium vs silicon or modern vs vintage...just npn vs pnp

[pinkjimiphoton]

Thanks guys, dont know what the farting sound was about, hooked up jacks so it was not going though my Beavis Board and it works fine flipping the caps

ummmm....you said:

I would like to change this NPN to a PNP FuzzFace

http://www.beavisaudio.com/bboard/projects/bbp_FuzzFace_Rev1_1.pdf

Do I just need to switch the polarity of the Electro Caps, and the flip GND and +9V rails? (as when I do this I just get a FAAAAAAAARRRRRRRRRRRTTTTTTT sound)??

What am I missing

lol...

[pinkjimiphoton]

yah, i mean make sure the trannys aren't backwards..

had me scared there for a minute...

the pinout between an npn and pnp are opposite.

opposite???  starting to get me scared again...

When you change from NPN to PNP, the EBC of the PNP goes exactly where the EBC of the NPN was.

what he is saying is that yes, EBC all go in the same place circuit-wise, but most germanium pnp transistors have their pinouts flipped from modern NPN transistors. so you usually have to flip the transistor 180 degrees from whatever layout you are using.

i can't see how that makes any sense...flipped from what?    there is no difference between  ebc and cbe. it just depends on which side you look at it from.  the only thing you have to worry about is with some transistors the pinout is bce or ecb...again, same thing

further, this had nothing to do with germanium vs silicon or modern vs vintage...just npn vs pnp

yah, it does matter imho.... the pins are opposite, and sometimes peeps don't notice that. an npn, like in the picture, is ebc from bottom to top...a pnp  would be cbe.

if you follow a layout for an npn transistor, and put a pnp in it the exact same way the pnp will be backwards and won't work.

however, if it's a ge tranny that leaks a lot, it can pass signal, and sound real blatty/farty.

i took a gambit the op knew as little or less than me. that's why i said that. remember when you were new at this, and didn't know which side of a transistor was what?

i mean, and i apologize if i'm unclear, that if ya plug an emitter where a collector is supposed to be, it plain don't work!

[LucifersTrip]

yah, i mean make sure the trannys aren't backwards..

had me scared there for a minute...

the pinout between an npn and pnp are opposite.

opposite???  starting to get me scared again...

When you change from NPN to PNP, the EBC of the PNP goes exactly where the EBC of the NPN was.

what he is saying is that yes, EBC all go in the same place circuit-wise, but most germanium pnp transistors have their pinouts flipped from modern NPN transistors. so you usually have to flip the transistor 180 degrees from whatever layout you are using.

i can't see how that makes any sense...flipped from what?    there is no difference between  ebc and cbe. it just depends on which side you look at it from.  the only thing you have to worry about is with some transistors the pinout is bce or ecb...again, same thing

further, this had nothing to do with germanium vs silicon or modern vs vintage...just npn vs pnp

yah, it does matter imho.... the pins are opposite, and sometimes peeps don't notice that. an npn, like in the picture, is ebc from bottom to top...a pnp  would be cbe.

if you follow a layout for an npn transistor, and put a pnp in it the exact same way the pnp will be backwards and won't work.

  haha...sorry man, I really don't know what your sayin' and really didn't want to confuse the OP.  can you give me an example?

for instance, if I was using a common npn like 2N3904:
http://transistor-spravochnik.ru/description/2n3904/3795


and I wanted to switch to pnp, 2N3906:
http://transistor-spravochnik.ru/description/2n3906/3800


I couldn't just put the 3906 in the same way?

[pinkjimiphoton]

yah, that would work. but sometimes ge transistors from the bottom go OPPOSITE that... c b e instead of e b c.

[Scruffie]

I think I can solve this argument...

Always check the pin out of the transistor you use on a datasheet.

Done.

[LucifersTrip]

yah, that would work. but sometimes ge transistors from the bottom go OPPOSITE that... c b e instead of e b c.

that's funny....now I know you're messin with me...

[pinkjimiphoton]

I think I can solve this argument...

Always check the pin out of the transistor you use on a datasheet.

Done.

all i'm sayin. yes, all transistors have an emitter, a base and a collector...but they aren't always in the same order!!

[LucifersTrip]

I think I can solve this argument...

Always check the pin out of the transistor you use on a datasheet.

Done.

all i'm sayin. yes, all transistors have an emitter, a base and a collector...but they aren't always in the same order!!

what I thought was so funny (and why I thought you were joking) is when you wrote "sometimes ge transistors from the bottom go OPPOSITE that, c b e instead of e b c"

most ge transistors are metal can cylinders, which are CIRCULAR, so there is NO difference between ebc or cbe.
There is no front, back or side to a circle...

[pinkjimiphoton]

this is true, but they're usually obvious where the base is. but sometimes...it'll be like this from the bottom
   b
e     c


and sometimes it's

   b
c     e

if ya look at a schematic of a pnp and an npn version of the same circuit,  it's opposite.

like this example:



see what i mean now? in one, from top to bottom, it's cbe, and the other, it's ebc.

in this case, on the left is a pnp, the right npn....notice where the emitter is. if ya look at a schematic where the emitter is on top, rather than the bottom, and then install a transistor where the emitter is on the bottom, it ain't gonna work...BUT if it's a really crappy leaky ge transistor, it may work either way...well, not work, but pass signal.

i swear to god i'm not f'n with ya bro, maybe i'm misunderstanding something here that i shouldn't be. i just look to see which way the emitter's arrow is pointing to see if it's pnp or npn. but i've noticed again and again, the difference between the pinout order of transistors. yah, they may all have e b and c connections, but they aren't always in the same order or place, and if converting a circuit from npn to pnp (like my liberal komrade pedal) the transistors need to be reversed in the sockets for it to work.

peeeeeeeeeeeeeeeeeace

[LucifersTrip]

if ya look at a schematic of a pnp and an npn version of the same circuit,  it's opposite.

like this example:

The only difference between an NPN & PNP in a circuit is the direction of the arrow. They are put in the circuit in the same orientation.

[Barcode80]

if ya look at a schematic of a pnp and an npn version of the same circuit,  it's opposite.

like this example:

The only difference between an NPN & PNP in a circuit is the direction of the arrow. They are put in the circuit in the same orientation.

..can't believe this has gone on this long... It's like Abbot and Costello in here.

He wasn't referring to the schematic. All he was saying was if you use a LAYOUT, and decide to flip the electros and polarized components on a LAYOUT to switch it, that you have to be mindful of the transistor pinout, as PNP pinouts for Ge transistors vary wildly. That's all.

[LucifersTrip]

..can't believe this has gone on this long... It's like Abbot and Costello in here.

He wasn't referring to the schematic.

not correct:

pinkjimiphoton: "if ya look at a schematic of a pnp and an npn version of the same circuit,  it's opposite."