I'm building a FF geared for much higher gain than usual...Q1 will be around 120, and Q2 will be about 250. I suspect that the standard resistor values will need to change to accomodate these increased gain ranges. Anybody have suggestions about which resistors will require adjustment, or the types of adjustments that may be required?
the fuzz face was built with much higher gain transistors (BC108C) for a while. it doesn't need different resistor values, just find a pair of transistors that sounds good together.
Quote from: Electric Warrior on February 17, 2011, 04:46:57 PM
the fuzz face was built with much higher gain transistors (BC108C) for a while. it doesn't need different resistor values, just find a pair of transistors that sounds good together.
The silicon FF's did have a different value of one resistor, most likely because of the higher gain trannies. Look at the schematics for the two different versions and you'll see.
Al
There are some mods to increase gain here:
http://www.geofex.com/article_folders/fuzzface/fftech.htm#mods (http://www.geofex.com/article_folders/fuzzface/fftech.htm#mods)
Make a coloursound 1kf? (82r should be 820r)
http://fuzzcentral.ssguitar.com/schematics/oneknobfuzz.gif
Quote from: zombiwoof on February 17, 2011, 07:25:35 PM
Quote from: Electric Warrior on February 17, 2011, 04:46:57 PM
the fuzz face was built with much higher gain transistors (BC108C) for a while. it doesn't need different resistor values, just find a pair of transistors that sounds good together.
The silicon FF's did have a different value of one resistor, most likely because of the higher gain trannies. Look at the schematics for the two different versions and you'll see.
Al
I know. They swapped the 470Ω for a 330Ω to reduce the output a bit. No big deal.
Quote from: Electric Warrior on February 18, 2011, 11:55:41 AM
Quote from: zombiwoof on February 17, 2011, 07:25:35 PM
Quote from: Electric Warrior on February 17, 2011, 04:46:57 PM
the fuzz face was built with much higher gain transistors (BC108C) for a while. it doesn't need different resistor values, just find a pair of transistors that sounds good together.
The silicon FF's did have a different value of one resistor, most likely because of the higher gain trannies. Look at the schematics for the two different versions and you'll see.
Al
I know. They swapped the 470Ω for a 330Ω to reduce the output a bit. No big deal.
Maybe no big deal, but that is what the OP was asking about.
Al
Just realized the OP never stated whether silicon or germanium. If germanium, most likely more than that 1 resistor will change.
Sounds like you're trying to build a Peppermint Fuzz
I am, actually (re: the peppermint fuzz). I love the sound of the dark peppermint fuzz and am trying to go for that. I am using a germanium for both Q1 and Q2, but I am thinking about seeing how it would sound to have a silicon in the Q1 position too.
Quote from: mordechai on February 17, 2011, 02:39:17 PM
I'm building a FF geared for much higher gain than usual...Q1 will be around 120, and Q2 will be about 250. I suspect that the standard resistor values will need to change to accomodate these increased gain ranges. Anybody have suggestions about which resistors will require adjustment, or the types of adjustments that may be required?
http://www.diystompboxes.com/analogalchemy
Check the link marked "electronics math helper" - then go to "Fuzz Face"
when i want a fuzz to sound more like a high gain distortion rather than a wooly thick fuzz i always lower the input cap significantly like .01uf or at least .1uf. sometimes as low as .001 uf. depending... if youre going to raise the actual 'gain' of the circuit via transistors and resistors, and leave the input cap alone your going to be amplifying alot of bass content and the tone will probably be very 'wooly thick' type fuzz tone...maybee thats what your after tho? ??? but if you want a fuzz to be tighter and sound and feel more like 'high gain distortion' than fuzzz i'd definately recommend a smaller input cap.
maybee some other fuzzficionados :icon_cool: will back me up here...
the input cap blend mod (I go from 0.0033uf to 2.2uf) is very useful I find.
as is the pre-gain mod (pot in series with input) for getting different textures out of the FF.
I've a hybrid on the breadboard now with 2n3906 (hfe 220) and AC125 (hfe 200+), with a 1k instead of the 470R.
using small caps across the base and collectors of each one is helping keep the noise down.
Germanium fuzz can sound pretty high gain with a 2k gain pot and when the voltage on the collector of Q2 is a little higher than 4.5 volts.
This one is pretty high gain http://www.aronnelson.com/gallery/main.php/v/rousejeremy/audio/Germanium+Fuzz.mp3.html
Quote from: rousejeremy on February 19, 2011, 12:54:37 PM
Germanium fuzz can sound pretty high gain with a 2k gain pot and when the voltage on the collector of Q2 is a little higher than 4.5 volts.
This one is pretty high gain http://www.aronnelson.com/gallery/main.php/v/rousejeremy/audio/Germanium+Fuzz.mp3.html
That is a great sounding fuzz. I would like mine to have a little more gain on tap, ergo the significantly higher gain transistors (Q1 120/Q2 250, or so). But you raise a good point re: input caps. I do want a nice full range without the tone getting too buzzy and high end, and I like the idea of having some dark "wool", but then again, I want to avoid it getting muddy.
Also -- someone made mention of putting small caps between the base and emitter of the transistors to reduce noise. Is this advisable for BOTH transistors or just the Q2? And what value caps would you recommend to smooth things out, noise-wise?
if anybody could give me a link to a nice hi gain Silicon Fuzz Face.. i'd be much thankful
Quote from: vendettav on February 21, 2011, 02:43:35 PM
if anybody could give me a link to a nice hi gain Silicon Fuzz Face.. i'd be much thankful
This one is great:
(http://www.muzique.com/schem/fuzzface4.gif)
from:
http://www.muzique.com/schem/projects.htm
Jack Orman wrote:
"I took a basic Fuzzface-type circuit and modified the component values so that a mosfet transistor could be used for Q2. The result was a high gain over-the-top distortion. "
Quote from: mordechai on February 21, 2011, 01:50:21 PM
Also -- someone made mention of putting small caps between the base and emitter of the transistors to reduce noise. Is this advisable for BOTH transistors or just the Q2? And what value caps would you recommend to smooth things out, noise-wise?
I use a small cap (~47-300pf) across collector & base of Q1 to eliminate noise
oh well i guess i cant get a mosfet.. and well i have a few JFETS and NPN trannies left at my place.. if i oculd go with those i'd be really happy :)