Per request.
There are a few schematics to choose from so I decided to use the one from Fuzzdog which has an internal trimpot so you can fine tune the sweep of the Sun Dial control.
BenSpinks shared the values from his RCA Mid Gain Sun Face. They differs quite a bit so here we have an RCA layout as well.
You can verify this one. Just build the silicon version, sounds really good but it starts to crap out at 90%-100% of the potentiometer sweep (also introduces some oscillating noise). I had the same problem with the layout from the tagboardseffects website though.
ReplyDeleteGain pot that is
DeleteYeah, that is a pretty common problem with stock silicon Fuzz Faces. A small value cap across the base and the collector at Q1 usually tames some of the noise artifacts. You can try a 100pF cap (or a larger value) at J11-K11.
DeleteAnd thanks for verifying! :-)
DeleteThx Fuzzhead! I've raised the 470r to 560r for slightly more volume/punch and I liked 100pF best and it removed the issues above! It sounds way more closer to the clips I hear on youtube.
DeletePerfect!
DeleteI am a newbie builder, no background on electronics what so ever. I build this one with BC109 cuz I don't have the BC108. It sounds good, but how to increase the volume on this one? Any suggestions....... Thanks!
ReplyDeleteYou can sub the 470ohm resistor for a higher value for more overall volume output. 680 ohm up to 1k usually works fine.
DeleteThank you very much fuzzhead!
DeleteAwesome, thanks very much for this one.
ReplyDeleteCheers
Ben
I was super excited when I saw this. After such an impressive result from the if six was nine, I think it might be a disappointment! 🤔
ReplyDeleteHold on! Wait a couple of hours and I'll upload something you might like!;-)
Delete❤️❤️❤️❤️❤️
ReplyDeletePeppermint Fuzz is up!
DeleteThat looks wild! I've yet to get involved with germanium...I'm slightly put off by it's (lack of) availability...I may have to change
Deletemy ways
Re. The small value cap...is this why I found the if six was mine so well behaved?
ReplyDeleteI see there's a couple of 220pf caps near each transistor....
(Forgive my lack of knowledge... this is all quite new to me)
Exactly. A small value cap across the base and the collector helps taming noise. For a stock silicon Fuzz Face, 100pF is a good value, it reduces noise without altering the base sound. Larger values will filter the high end and make it smoother sounding. Meathead is an example which has a 470pF cap at Q1.
DeleteThank you.😊 I've made the suggested changes and put a link to the image.
DeleteI think it's well worth a shot with the changes... Fuzz faces always seem to be my favourite
Might be worth mentioning that the newest germanium Sunfaces have slightly different component choices when compared to the original schematic. My Sunface (RCA mid gain) uses 62k and 680r resistors in place of the 33k and 470r, a 20k internal bias and a 10k sundial.
ReplyDeleteThanks for the info! I think it is worth adding a "RCA" layout since it differs quite a bit. Which RCA transistors is in yours?
DeleteThe transistors read 112011, which is nothing like any RCA code I’ve been able to find online. Apparently they’re just the usual mid gain fuzz face spec, so any PNP should work fine. Will build one up later to compare.
DeleteI take it back. Just found them on Small Bear 🥳.
DeleteMade one up with some OC42’s, which are higher gain and a bit brighter than the usual FF fare, but I’d say the 10k sundial is much more useful than the 5k, which I’ve never found very useful. The 10k matches up with my original Sunface perfectly. It’s also way louder and a bit more open sounding than my previous attempts.
DeleteI can’t get any of my other transistors to bias low enough, which I think must be down to the leakage in Q1. OC 84’s with Q1 at 64 hfe 0.15ma and Q2 at 82 hfe 0.25ma wouldn’t let me get down to -4.5v. Would you expect that normaly?
Ok, forget that. 51K fixed it and it biassed perfectly. Interestingly CV7007's needed to go back down to 33k. Socket those resistors kids!!! :-))
DeleteHey Ben! Thanks for all the research you have done on this one.! An additional RCA layout is added to this post so anyone can build it. You don't happen to have the voltages from your original Sun Face....just for science you know?;-)
DeleteSure here you go:
DeleteQ1
c -0.75v
b -201mv
e 0.00
Q2
c -4.5v
b -0.75v
e -517mv
Sundial fully counter clockwise Q2 -1.92v
Sundial fully clockwise Q2 -7.07
Cheers
Ben
P.S. The RCA's are 112011
Well I finally got the courage to desolder the RCA transistors in my Sunface.
DeleteQ1 = 119 hfe
Q2 = 134 hfe
Leakage for both is 0!!
I'd add also that this was classed as a medium gain Sunface.
DeleteLike this???
ReplyDeletehttps://photos.app.goo.gl/nSba8P4P9qXXgqp56
Beautiful. thank you (really - I'm enjoying all these builds so much. You're keeping me sane, and giving me the distraction I need)
DeleteIn a similar vein to this....have you ever made a layout for the fulltone 70? (three knob BC 108 version)
ReplyDeleteIt wasn't on the list but it is now! Not sure when it can be done though...
DeleteIt should also be noted that carbon resistors sound best in this circuit.
ReplyDeletemaybe a stupid question but are trimmers made of metal or carbon film?
DeleteThere are no stupid questions, dude. And, after all, a trimmer (trimpot) is a variable resistor. Most of the time it is made with carbon or a ceramic stuff called cermet.
Delete😊😊😊
ReplyDeleteWould it be possible to do a mojo layout for this?
ReplyDeleteYes. Do you mean with 0,5w carbon comps and axial capacitors?
DeleteYes please.
DeleteBuilt the Silicon and PNP Germanium version. The silicon works well, sounds like a fuzz face with BC108s. I am getting some pretty obnoxious high pitch squeels when the fuzz pot is maxed, which goes away when turned down, which sucks because I can not get a dimed fuzz tone without it squeeling out on me. If anyone else is having this issue, Let me know! I am gonna build another and see if it persists.
ReplyDeleteThe PNP Germanium was a bust. It is extremely low, gated, poorly biased output no matter what transitors I use. It will not ring through the gating unless I play harsh on the Lowest 2 strings. I tried a few pairs of germanium, and 4 different sets of PNP silicon with no luck. Can not seem to get them to bias correctly. I built a second to see if the problem persists, Ill update if all goes well.
That's weird, the filter cap usually solves the squeal issue. But if you want more fuzz, just under bias Q2 a little. I always bias by ear. Just screw with the trim pots. If you don't get the sound you want then try different trans. It's hard to beat a good Fuzz Face. BC183's are my personal favs.
ReplyDeleteNaw sadly the trimpot does not make it go away some settings are better but the fuzz pot maxed squeels on every setting... I am gonna try a small pF cap from emitter to base of the Q1 and see if that helps on the next build
DeleteYou might also try a 500k pot for the Volume control. I prefer it to the 250k personally. The 1uf input and the 250k pot accent the mids a tad too much for my taste. It might tame the overall tone a little.
DeleteThe output caps on the silicium Sunfaces are 104J = 100NF
ReplyDelete10nF with 250k pot as shown of many schematics and layouts will give a very bass lacking fuzz...
Also the voltage divider resistor 470R should be in fact 390R (in the silicium version)
DeleteBuilt it and love it.... thanks.
ReplyDeleteMost of the BC108 Sun Faces I'm seeing don't have the sundial. Analogman's website says it's on there to keep the Germaniums happy in different temps. With the silicon do you need the sundail and internal bias pot?
ReplyDeleteShort answer: probably not.
DeleteHowever - if it were me building this, I'd 1) socket in order to audition a bunch of different transistors, and 2) leave in all the pots the first time around just to see what sounds I could coax out of it. You can do a lot of cool stuff to a fuzz face with just a little variation.
You don't "need" the bias pot, but I always want one. It's part gain control and part tone control. I might even hard set the fuzz control and use the pre gain as the fuzz control and then use the bias to get anything from high gain fuzz to dying battery fun.
DeleteI'd like to build one of these without the sundial pot. Would I just need to jumper from E1 to G1?
ReplyDeleteYes
DeleteThanks, Ian
Delete