Transistor gain of 200+ & fuzz faces?

[WoundUp]

Got a question about what I'm measuring on these 2n2222(100) & BC109C(2) transistors and what to use in a fuzz face circuit.

So far, every 2222 I've checked(out of the 100 I have) reads over 200 when I plug it into the DMM. I've only checked 5 or 6 but they all measured virtually the same. The 109's measured at over 600.

Will these be OK to use for a fuzz face? Is the gain in these too high? I read that fuzz faces like a combo of around 90? on the 1st and 120-140, IIRC, on the 2nd transistor in the circuit. If that's the case, does that make these unusable?

I still need to go through the other 90+ 2222's and measure those, too. So I'm hoping I'll find a few that measure a bit lower than the 200+ that the 2222's I checked measured. In case I don't, what do I do? Use two 200+ 2222's? Use one of those and a 109? Buy more and hope I get what I need? Pay extra for a hand-picked set?

I appreciate any and all help. I'm very new to this so I know hardly anything about this except what I've read in the last few weeks. Thanks.

[FiveseveN]

I read that fuzz faces like a combo of around 90? on the 1st and 120-140, IIRC, on the 2nd transistor in the circuit.

That's for germanium transistors, yours are silicon. Look for "Silicon Fuzz Face": http://www.home-wrecker.com/sili-face.html

I still need to go through the other 90+ 2222's and measure those, too.

Did you know the manufacturers do that for you?

[kaycee]

You can use what you have, just get sockets for the transistors so you can swap them out to taste once you have a working build. High gain transistors will just mean that you will have to turn down the guitar volume further to get it to clean up. You can mitigate the gain by putting in a pre gain pot at the start of the circuit. Low gain silicon are available, do a search through the forum for examples.

With a batch of transistors, I usually grab a half dozen, measure the gains and write an average on the bag, most will fall near that number, it's only germanium ones I'd go through the whole batch.

Build it, you'll like it or not, but at least have a starting point for refinement.

[Gus]

You can use different beta Silicon transistors if you adjust the circuit

Do a few search here for fuzz circuits

this might help
https://www.diystompboxes.com/smfforum/index.php?topic=114153.msg1059002#msg1059002

[iainpunk]

i believe both work in ''Reverse Beta'' operating mode, which nicely reduces gain. (fancy words for ''try them with the C and E swapped'')
i really like reverse beta transistors in fuzz cicuits, they make it sound more ''vintage'' in my experience.

cheers

[duck_arse]

if you've got a bag of sillicon all from the same batch, don't bother testing all, they will be very consistent. look through the parts and see if you can spot any differences in markings, date codes or 'a' suffix or PN as opposed to 2N or different manufacturer, and then test the variants. probably still won't get wildly different numbers, but a little here or there.

the C batch of all BCxxx transistors is sorted to have the highest gains, so you probably want to save those for something non-face.

[Marcos - Munky]

You do can use them. If they'll sound good to your ears, that's a different matter. Some people says ge fuzz faces are the best. Other people says si fuzz faces with low hfe transistors are the best. And other people says si fuzz faces with higher hfe transistors are the best. It's a matter of opinions.

If you want to give a try on low hfe si transistors, the PN2369A is a NPN with the hfe on the 40-120 range. I used a pair on a fuzz face I built and actually liked it more than a ge fuzz face I tried before this one. But I'd try what you already have before buying anything else.

[Gus]

If you look at the link in my other post you will see two different beta ranges for the Si transistors

you can adjust for different betas

[mac]

Some people like to add an emitter resistor at Q1 if gain is high. But the input impedance gets higher -> hfe*Re. Worth a try.

mac

[Electric Warrior]

200+ will work fine. A silicon fuzz face needs higher hfes to bias right (with stock resistor values). 600 may be a little much, though.

[WoundUp]

I guess I should've specified. I'm going by this circuit at the Smallbear website to build a silicone fuzz



http://diy.smallbearelec.com/HowTos/BreadboardSiFF/BreadboardSiFF.htm

I also didn't get far enough down the Smallbear page before I posted as I'm pretty sure it goes over what to do with higher gain and how to adjust the circuit for it. I'm completely new to this so I apologize if I leave info out or forget to post something useful. Like it mentions replacing the 8.2k resistor with a 10k trimpot and I actually have one of those I could use. I just need to sit down and take the time to build the circuit and finish reading so I fully understand what I'm doing.

if you've got a bag of sillicon all from the same batch, don't bother testing all, they will be very consistent. look through the parts and see if you can spot any differences in markings, date codes or 'a' suffix or PN as opposed to 2N or different manufacturer, and then test the variants. probably still won't get wildly different numbers, but a little here or there.

the C batch of all BCxxx transistors is sorted to have the highest gains, so you probably want to save those for something non-face.

It appears that all of the 2222's are from the same batch. I've also got maybe 10 2222a's from a different mfg/batch.

As I said I'm new to this so I didn't know that an entire bag would all probably have the same specs. It was about the same price to buy a couple as it was an entire bag so I went with the bag thinking that they would vary. Either way, I'm not out any money if I don't use them all. I paid $6 for these and it's that much for an order of a few from Smallbear.

I've got everything except the cap kit I ordered and I can, build it without that for now so I'll probably get it out here shortly since I can't sleep. I need to solder wires to the full-size pots and see what else needs to be prepped and I think I'll be ready to go.

[WoundUp]

Got the breadboard built. That wasn't so bad. All that's left is adding the input & output jacks and the battery and testing it out. I'll wait until daylight to do that lol. Oh, I need to swap those BC109s out for some 2222s, also.



VS

[percyhornickel]

My build has a BC109 transistors.

Q1 hfe 248 /Rc1 33K /1.3Vc

Q2 hfe 255/ Rc2 Trim / 4.5Vc

I like that "Gilmour sound" I get when I put a delay after it and max fuzz.

I am thinking to change later the B1k to C1K to make it more friendly but C type pots are just an illusion where I live so I need to live with I´ve got.


PH

[WoundUp]

My build has a BC109 transistors.

Q1 hfe 248 /Rc1 33K /1.3Vc

Q2 hfe 255/ Rc2 Trim / 4.5Vc

I like that "Gilmour sound" I get when I put a delay after it and max fuzz.

I am thinking to change later the B1k to C1K to make it more friendly but C type pots are just an illusion where I live so I need to live with I´ve got.


PH

Edited to add: I GOTTA FUZZ PEDAL! WOOHOOO! IT WORKS! And it actually doesn't sound near as bad as I was expecting.



Sweet! Thanks for sharing that. Those hfe values are much closer to the values of my 2222's. Whats the spec on the trimpot? 10k?

I got mine together and checked voltage at the collector on Q2 and got 5.4V

Unfortunately, I'm getting no sound. I can hear the level going up and down as I adjust that knob. I get a little bit of static and can hear it go up or down as I adjust it. I've just got no fuzz. Probably going to pull it all off and start over with my board in the same orientation as the example so I can make sure I've got everything right. Theirs has the + and - rows opposite of what mine are so I flipped my board so POS & neg would match but the middle doesn't. Going to go back to having the middle match the example and the POS & neg flipped. Sorry if that's confusing. I tried to explain it the best that I could.

I really appreciate all of the help from you all. Thank you!

[percyhornickel]

Yes I used 10K trimmer so I can adjust Q2c easily.

Check the caps orientation, YOUR INPUT CAP IS BACKWARDS!!! 

Volume Lug 1 goes to ground, you are connecting right to 9V (the blue jumper besides 330 Ohm resistor below) 

P.H.

[WoundUp]

I got it working last night after I stripped the board and redid everything. I caught the backwards cap about that time. Thanks for pointing that out.

It actually sounds pretty good, imo. I may swap the trimpot in and see how lowering/raising the bias voltage affects it. As it is, I've already ordered a kit with 2 FF pcb's, one for a NPN silicon build and the other for a PNP germanium build, so I can mount it permanently and get it into an enclosure.

I think I might have just started myself down a loooooooong rabbit hole LOL.

EDIT: Yep. I'm officially addicted to building pedals lol

[WoundUp]

Another update:

I remembered I had a 5V breadboard power supply so I got that out and powered the fuzz face with it. Talk about fuzzy! It was starting to spit & sputter at 5V so thats obviously too low. I also replaced Q2 with a BC109c with 600+ gain and gave it 9v again and it actually didn't sound that bad. It's definitely usable.

I ordered the circuit boards yesterday and I got an, aluminum pedal housing ordered today along with some pcb-style 500k pots. In hindsight, I should've ordered the kit with like 8 different values but I didn't. I will next time. I realized this when I started looking at clean boosts and realized I needed more pots lol.

Man I like this. This kind of stuff is right up my alley. I told my family I was gonna need a loan to start up my new pedal(& amp?  ) company 

Edit: sweet! I was able to cancel my order for the 500k pots and buy the 105 pc kit for $5 more. I just went from 24 pcs to 105 for a $5 increase. Not bad. It comes with 1k, 10k, 50k, 100k, 500k pots and 5 different trim pot values, as well. Plus 25 knobs and washers & nuts for the pots(25x2).

[PRR]

....I had a 5V breadboard power supply ...powered the fuzz face with it. Talk about fuzzy! It was starting to spit & sputter at 5V so thats obviously too low....

Re-bias it. Say 3V-4V on Q2 Collector. It should go clean to fuzz as commanded. It may need some trim of the 680 to bring the output level up to nominal.

This circuit works fine down to 3V, when adjusted for the volts you have.

[WoundUp]

Thank you. I got the trimmer installed. I couldn't recall what you recommended so I set it at 4.5v for the time being and it sounds friggin great with a 9v supply! I'm quite pleased with myself lol. I've now got a fuzz face that would've cost me just a bit more to buy already assembled in a nice round enclosure lol. Also, I can, now understand why Josh @ JHS includes a bias knob on his fuzz pedals. I would too. You can reay adjust how it sounds with that.

Thank you for all of the help. It is greatly appreciated.

I also ordered myself some soldering tweezers to help pull things off of the breadboard, pick up small parts, hold stuff while I solder, etc... They stay closed automatically and you open them instead of like standard tweezers that you squeeze closed and then open up automatically. I've got some hemostats, too. Thinking about it, locksmith tweezers might work too. They have ends that are shaped to hold the pins inside of locks so it might help hold small pieces like diodes, resistors, etc...