Input Buffer for Fuzz Face.

[Plexi]

Update
Messing around with my boosters, preamps, and buffers I discovered that the EQD Speaker Cranker, with "more" knob all the way down (gain in 0), is the best one as a "buffer" before the FF.
Doesn't change too much the tone and character; maybe with a bigger input cap in the SC get a more natural/darker response.

Why? I don't know.

[Gus]

Buffers are circuits that have a gain of about 1 and have a controlled input and output impedance.
The EQD is a gain stage that I would add two more resistors. At min gain open loop of about X2 along with the interaction of the 2.2meg feedback bias resistor and what is in front of the circuit.
Look at the BMP circuits

There are a few ways to build input stages
The one in the Rocket 3 transistor (did you look at the links I posted? did you compare the hipkitty to the rocket? ) was made back when effect parts were harder to obtain so most parts of it were available at Radio Shack
The bias is offset from 1/2 because of Vbe drop and output drive (the transistor can turn on harder than the emitter resistor can pull it back down)
I don't like darlingtons at 9VDC as buffers there is a better two transistor compound pair with one Vbe drop vs the darlingtons two Vbe drop
The input resistance was selected by the voltage divider bias, beta , emitter resistor and following loading
I am not posting this is the best buffer it was something that I liked.

Now think about what is different between what you like and other circuits

A search at this forum and the web of your questions should get a number of links to read to help you understand how different gain stages interact with the guitar and cable

[Plexi]

Thanks for your explanation Gus.
Yes, I saw every schematic...but patience please
I started 'read' schematics a few weeks ago, and english isn't my mother tongue.

Thanks again, and I'm analyzing each recommendation 

[roseblood11]

Would it be possible to build a buffered fuzz that reacts to the guitar's volume knob as the "real" fuzz face does?
Woulr require a circuit that "sees" the impedance change at its input and translates it to ann impedance change at its output. Can this be done?

[Plexi]

Would it be possible to build a buffered fuzz that reacts to the guitar's volume knob as the "real" fuzz face does?
Woulr require a circuit that "sees" the impedance change at its input and translates it to ann impedance change at its output. Can this be done?

I've tried several, and it's sonically impossible to get the natural interaction.
The most "closer", but still far, is this simple one:

[amptramp]

Would it be possible to build a buffered fuzz that reacts to the guitar's volume knob as the "real" fuzz face does?
Woulr require a circuit that "sees" the impedance change at its input and translates it to ann impedance change at its output. Can this be done?

I've tried several, and it's sonically impossible to get the natural interaction.
The most "closer", but still far, is this simple one:

A fuzz face does not really like a low source impedance, so a resistor in series with the output may be necessary.  To get the tone sucking of a real fuzz face, just use a 1 meg pot in place of R1 so you can set the buffer input impedance wherever you want with the slider connected to ground.  The control could be labelled "SUCKAGE".  When you see that control it should automatically remind you of me.

[Plexi]

Great... breaboarding that! 

EDIT: wrong schematic!
I've confused the link 

The one I've used is this one


Another very very clean, but isn't a propperly "buffer", is the Big Muff recover stage.
Almost the same schematic of the LPB1, but with fixed output (390R to 2k7 resistor emiter-ground).


Why???
I really don't know... just an empirical coincidence

[Bill Mountain]

I've given this a lot of thought recently.

What I want to experiment with is having an optional buffer on a vintage fuzz circuit  (like a FF or TB) with an active or passive bandpass filter (either fixed or adjustable somehow) to allow me to control the bass and treble response after the buffer and before the fuzz.

I'm coming at this from a bassist perspective but when I use a buffered pedal before a fuzz face there is simply too much bass and treble.

For an active approach I'm gonna experiment with the mid band from a state variable filter.

As a passive approach I think I'm just gonna try simple RC low pass and high pass filters in series between a few buffer stages.