very nice one knob fuzz

[Gus]

IMO a nice tuning of a one knob Silicon based fuzz yes around 1.6VDC and 7VDC.  Does not gate and sounds a little different because of the biasing
Built it on a 9 x16 stripboard with a board mounted volume control. Needs a good layout and short wires. Omit parts to the left of R9
Yes 100uf at the emitter I like how this seems to bring up more IM and collector voltages close to the sim voltages.
I am not a fan of C to B caps I like the lowpass at the output resistor.
Yes another FF like circuit and close to other FF like circuits. This one is about adjusting for easy to get 2222s.
I also like to use a 100k volume control



Q1 147 on a Radio Shack meter, 215 on a Centech, Q2 155 on a RS, 225 on a CenTech.  Different meters can give different beta measurement

Read LucifersTrip posts http://www.diystompboxes.com/smfforum/index.php?topic=103452.msg930078#msg930078

[Bill Mountain]

Is this lower gain to help avoid gating?

[Chris S]

Have you got a link to any audio through a fender like amp? Sorry for the specific ask - have built a couple of fuzzes which sound very different through different amps and not so good through mine. And... And link to the strip board layout? Thanks!

[Gus]

Is this lower gain to help avoid gating?

Gain is not that low it is all about the operating points of the transistors. 
The about 1.6, 7 biasing(LucifersTrip posted about Q2 collector being about 7VDC in a one knob build look at the links in my first post) changes the distortion harmonics/partials structure to my ear. I should run a FFT on the sound as confirmation.
With a FF like setup like this one, R1 and R7 are what you should adjust first
example for 2N5089s around 500 try a 8.2K and 220K

I have recently built 7 one knob FF like circuits with different adjustments.  I posted some adjustments in another thread.
With a FF like circuit set at max gain the feedback part of the R7 feedback/bias in minimized with a large enough emitter bypass cap.

The builds were done for fun and what could I do with a volume only FF like circuit. 

The 100uf is a fun thing to try.

[Cozybuilder]

I breaded it, and it sounds great, with lots of sustain. I used exactly what you listed, then tried a 1 k gain pot on Q1E with the cap on the wiper. IMHO you nailed it with the above circuit. One knob is fine, your guitar dialed back gives about the same response  as the gain pot did, so its not needed. This is the perfect candidate for someone wanting to try their skills with a small box build- this could easily be done in a 1590LB using a 16mm pot.

[Gus]

The last two I built are based on about 1.6, 7 .  Reading LucifersTrips post about this type circuit bias and other posts about people having issues biasing transistors in circuits like this I decided to sim and build some.
I noticed after sims and builds the LT spice 2222 model sims close to a build so I selected 2N2222s for the transistor hfe/beta range to adjust values.

So using the 2N2222 model I adjusted some values in LT Spice and built two like this.  First one had 100 and .22uf, 2.2K second 330 .068uf, 2K at Q2 collector. Second build is in a enclosure.

Cozybuilder thanks for the feedback.
Did it have a different "sound" than a 4.5VDC biased Si FF like?
Do you have any gating?

[Gus]

Maybe I title threads wrong

This is a very good tuning of a FF like fuzz.  It is now in a silver glitter painted enclosure.  I even gave two sets of beta readings, however most real 2222s should work fine without selection.

You can use the colorsound etc. one knob strip-board layouts as a starting point for a layout of this. Keep the wires short.

Omit things to the left of the X, R8 is a 100K a volume control.

Not much different than all the other one knobs however this was adjusted for easy to get 2222s.

A little extra information. 
I bought some new 2N3904s and 2N4401s for builds recently they do not measure like motos and other brand name older 2N3904s and 2N4401s that I have. 
Beta measures much higher. 
The parts only cost penny's each, are inexpensive transistors counterfeited?
I have old databooks that show the die dimensions and patterns.  Anyone know how to dissolve the material that covers the dies?
Maybe I will fix my curve tracer to do some more tests.

[B Tremblay]

Thanks for sharing this, Gus. I have the circuit all set on the breadboard and measured voltages, but haven't plugged in yet.

I used some NOS 2N3565 button package that have about the same hFE as yours, measured with my Radio Shack meter. I do have some old metal can 2N2222 that I sorted for good Si FF gains that I can try once I find them.

[B Tremblay]

After a brief playing session at a family friendly volume, I can certainly say that this is a fun circuit. It has nice harmonics, but without fizziness. It is certainly heavy enough! Rolling off the guitar volume provides another texture - sort of a nicely diluted version of the full fuzz. I hope to spend a bit more time with it once I find the 2222s.

[PRR]

> new 2N3904s and 2N4401s for builds recently they do not measure like motos and other brand name older 2N3904s and 2N4401s that I have. Beta measures much higher. The parts only cost pennies each, are inexpensive transistors counterfeited?

Today you can get a *billion* transistors on a CPU. (No, they are not NPNs but the basic technology baking is closely related.)
https://en.wikipedia.org/wiki/Transistor_count#/media/File:Transistor_Count_and_Moore%27s_Law_-_2011.svg

Where they used to sort '2222s into OK, low-gain-rejects, and duds; now they can make them 99% good and 98% at the very top of the gain range. Price is not quite $999/1,000,000,000 extrapolated from CPU $/transistor, but is little more than the cost of epoxy and leads and handling distribution.

If a vendor is charging more (without added service such as, one-of sales, convenient selection, or strong no-fakes policing) then maybe they are stuck with old-production bought years ago at higher prices. Like the local supermarket still charging $13 for an LED bulb, when H-D and WalMart have dropped below $3.