Steby fuzz (easy thingy) schematic

[Steben]

Simply a PNP Steby boost with direct coupled NPN steby boost.
Nice beginner project, no?
With fuzz P1 backed down, you still have a nice booster.
I guess it works with germanium as well as silicon.

[earthtonesaudio]

Very elegant.   

[Gus]

IIRC At Jack's site he had a schematic of a 60's fuzz circuit it was a EF, volume pot then a stage something like that

[Steben]

IIRC At Jack's site he had a schematic of a 60's fuzz circuit it was a EF, volume pot then a stage something like that

Dou you mean this?
http://www.muzique.com/schem/sixties.gif

Well, the big difference is the very low parts count and the input bias/fuzz combination in one pot.
The Steby fuzz can behave a lot as a typical low impedance loader (as wah's, bazz fuss and FF), while the 60ties fuzz has much higher input impedance.
The volume pot is actually a Rangemaster trick. 

[Dragonfly]

[morpha2]

Nice layout! What does the Steby sound compare to?

[liddokun]

Why not breadboard it and find out?

[Marc.yo]

correct that absolute error in the LED - ampere measurement!!!! lol

other than that it looks cool

[Steben]

correct that absolute error in the LED - ampere measurement!!!! lol
other than that it looks cool

Why?
because there is none? 
Standard info on my projects...
3300 ohms resistor on high efficient LED gives 2.5mA.

@Dragonlfy:
Dude,...
You are awesome, man... 

[liddokun]

It's almost too simple I want to cry.  I'm digging seeing circuits like this up more often, I can spend a quite weekend afternoon with my breadboard and build and test like...10 different fuzzes like this and see what they sound like.  The parts are not only low in number, but common.

[earthtonesaudio]

You know, it looks simple but it's actually pretty interesting how it seems to work... (I may be wrong though)

The 100k pot acts like a voltage divider for AC but as a fixed resistor for DC, using the "fixed bias" configuration, but adjustable. 

The PNP transistor acts as a current source for the NPN.

If I had this on the breadboard right now, I would be interested to see what happens if you connect the bottom lug of the 100k pot to the collector of the PNP instead of ground...
And also what happens if you connect the emitter of the PNP to the collector of the NPN.

[DougH]

Hey, are you copying me???

[Steben]

You know, it looks simple but it's actually pretty interesting how it seems to work... (I may be wrong though)
The 100k pot acts like a voltage divider for AC but as a fixed resistor for DC, using the "fixed bias" configuration, but adjustable. 
The PNP transistor acts as a current source for the NPN.

the 100k pot is not fixed for DC.
With the pot all down you have grounded PNP base, which is the same as supply voltage to base of a NPN.
;-)

If I had this on the breadboard right now, I would be interested to see what happens if you connect the bottom lug of the 100k pot to the collector of the PNP instead of ground...

Seems feedback bias.

And also what happens if you connect the emitter of the PNP to the collector of the NPN.

emitter of PNP is at +9V...

[earthtonesaudio]

Eh, I mean "variable resistor" not "fixed resistor."  Funny how the brain thinks one thing and the hands type another.

the 100k pot is not fixed for DC.
With the pot all down you have grounded PNP base, which is the same as supply voltage to base of a NPN.
;-)

Hm.  Might not be the best thing for device longevity.

[Steben]

the 100k pot is not fixed for DC.
With the pot all down you have grounded PNP base, which is the same as supply voltage to base of a NPN.
;-)

Hm.  Might not be the best thing for device longevity.

No, but no one plays with the gain on zero; there will always be some Kohms as bias resistor.

[earthtonesaudio]

Good point.  But I needed practice making layouts, so here's my over-engineered take on it anyway (not verified):




I didn't remember the values of the capacitors when I got home, so I just made them all 10u, oops!