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I had the exact same problem with a Tayda MK3 build. With the help on this forum I got it going.
https://www.madbeanpedals.com/forum/index.php?topic=33542.msg322007#msg322007
What's the volts at collector of Q1? needs to be 4.5v +-

That's I wanted to attach now :@(  Another version.

Google search answered my question

When building say a fuzz face using SI transistors does the hfe of Q1 and Q2 matter like when using germanium? When using germanium I've read Q1 hfe should be + - 75 % of Q2 but does that matter when using SI transistors ? Or is that why there are trimmer pots in most SI fuzz faces to get collector of Q2 to proper voltage ?

Thanks for the info

"Silicon transistors aren't "lossy" like germanium ones, so you just have to simulate the leakage in some way"
I've seen this kind of wordage on many sites when talking about using SI in circuits designed for germanium. I've put together a few PCBs RM, FF and TB from tayda and used SI in all w/out issue except the TB, with help on this forum got it going. In simple terms what does the above statement mean? Do the PCBs I've mentioned above have some kind of simulated leakage in the circuit ? How do you simulate leakage in a circuit?

Great work! Now only tuning: Try biasing Q2 and especially Q3 too. But now set that 4,5 or better 4,8 V only at Q3 collector. Trimmer Q3 bias try at half setting, and play with Q2 bias trimmer - gating. (In tonebender III that I attached you can see even another resitors around Q2 and Q3. You can try them in your device.)

For a better fun I attached schemas of Suck fuzz - improved Tonebender, where you can play with many settings at breadbord. One for npn and one for pnp transistors. You can rebuild that your machine in to a Hell of fuzz :@)
Confused again. I've got Q2 biased at 1.23v per tayda instructions and Q3 is at 4.51v. Are you saying to bias Q2 to 4.5v as well ?

Thanks for all the help. 400k is the resistance I needed to bring collector of Q1 to 4.5v. Don't have that so I ran a 330k + 62k in series and tacked onto the back of the board. sitting at 4.32v on collector of Q1 now and now have a useable circuit !!
new issue the 1kb fuzz pot does very little in the way of changing the amount of fuzz, is the 1kb the wrong value here or maybe change it out. its already attached to the board or i would just try something else

Ub/2 is one half of power supply. Sorry not to be clear. Picture in first post is one solution, and another picture Tonebender III is another. Try both of them and you will see what you get. Both of them will work. Here is another kind of bias setting:

http://www.hawestv.com/transistorize/germanium1.htm

All will work with proper resistors, you must find. Use trimmer and try to set cca 4,5V at collector of Q1 (for 9V power.) Then substitute with resistor with closest value.

That is great, thank you for the help, and now I know what Ub/2 means. I will save link and read through when I have time.
I guess that Tayda build doc should be updated for when people use SI transistors. I can't be the only 1 that has had troubles

First transistor hasn't bias from plus pole to basis! I would put here cca 680-820k resistor. Set with this resistor cca Ub/2 at collector of Q1. That's for a start.

Sorry I'm not sure what Hb/2 is.
I think what you're saying is run a 680-820k resistor between collector and base of Q1 ??

I've attached a screen shot of schematic, its a Tayda board and I didn't mention I am doing an NPN version. I have electrolytic caps reversed as per instructions on site
Still curious about the hfe values. If building SI version is measuring the hfe needed for each position?
https://www.taydakits.com/instructions/tone-bender/pages/designators-and-components--35

Sorry if this is a dumb question but having trouble with a tonebender build. I'm putting together a TB on a PCB and have socketed the transistors and using 2n3904 and can't get more than farty noises out of it. The question I have is they recommend hfe for Q1, Q2 and Q3 when using germanium transistor's but is that still the case when using SI transistors? I can get it to bias to the correct voltages but no sound unless strum real hard and it sounds farty and fades out real quick.

If you're going to breadboard it, I'd suggest you try it with a 10uf and see if you like it.  It won't explode, so experiment. 

Put two 10uf in series to get 5uf, see if that makes a difference to the sound.  That might help you decide if you need the 2.2

The other thing you could do is read up on the fuzz face... geofex has a really detailed article here http://www.geofex.com/article_folders/fuzzface/fftech.htm

That is a lot of info  Thanks for the link

You'll see in the above link that the original circuits used up to 20uf, so I don't think it will matter much anyway!

Thank you for the response  will read the article

Thank you for responding. its a SI fuzz face I found on the web with step by step instructions that I want to give a try on a breadboard. I'm new to breed boarding. I've always just put together MB boards or Tayda boards. I have a bunch of caps and resistors pots and diodes just no 2.2 or 1 uf electrolytic caps though

As above, can I use a 10 uf in place of 2.2 the schematic calls for ? will be same 16v.
If not how come?