The transistor needs to see a positive charge on the emitter and negative on the collector. As long as the guitar signal (AC) grounds on the other side of the coupling caps, it doesn't matter that it grounds negative and the DC on the transistor is grounding positive...in theory. You can run into feedback issues and motorboating on some of these. Jack Orman has published an article on his site about running a PNP fuzz face on negative ground, and some people say they've gotten it to work well. It will work for me, but I always get bad motorboating. There are some very creative uses for PNP in circuits like Roger Meyer's Axis Fuzz and the Jordan Bosstone. In particular with the Axis, I believe that it was a way to create a circuit that behaved similarly to a fuzz face, but without the impedance issues, which meant Hendrix could use his wah going into it. I personally think it's pretty clever.
I just took a look at it. It's possible that all the issues I've had are just because I'm doing it on a breadboard, but I've been reluctant to box it up when it wasn't working right. This layout has the filtering done differently, and a little more elaborately so I'm going to take a look. It's quite an area of debate on forums, because people can have vastly different experiences using the same layout.
Yeah, there are some interesting deviations from the original Fuzz Face... the most interesting is the 220 ohm resistor coupled with a total of 660uF in capacitors on the first transistor. I assume it stabilizes the transistor, but the capacitance has to be to stop oscillating (it doesn't have to, it's just the way I'm thinking.)
Awesome. Thanks for double checking. It worked the first way but the schematic I came across when looking for bias voltages was different. Thanks for everything you do buddy!
Input goes to switch 2 ;-)
ReplyDeleteDoh! Fixed.:-)
DeleteHi! Thank you so much for a lot of shemes. 1N5817, 1N4001, 1N4004 and 1N4007 is same effect?
ReplyDelete1N400X will have a slightly larger voltage drop than 1N5817 but in most cases the circuits works fine with both.
Deletenegative ground with pnp transistor, hows that work ????
ReplyDeleteThe transistor needs to see a positive charge on the emitter and negative on the collector. As long as the guitar signal (AC) grounds on the other side of the coupling caps, it doesn't matter that it grounds negative and the DC on the transistor is grounding positive...in theory. You can run into feedback issues and motorboating on some of these. Jack Orman has published an article on his site about running a PNP fuzz face on negative ground, and some people say they've gotten it to work well. It will work for me, but I always get bad motorboating. There are some very creative uses for PNP in circuits like Roger Meyer's Axis Fuzz and the Jordan Bosstone. In particular with the Axis, I believe that it was a way to create a circuit that behaved similarly to a fuzz face, but without the impedance issues, which meant Hendrix could use his wah going into it. I personally think it's pretty clever.
DeleteThe Dunlop ge Fuzz Face on this site works great.
ReplyDeleteI just took a look at it. It's possible that all the issues I've had are just because I'm doing it on a breadboard, but I've been reluctant to box it up when it wasn't working right. This layout has the filtering done differently, and a little more elaborately so I'm going to take a look. It's quite an area of debate on forums, because people can have vastly different experiences using the same layout.
DeleteYeah, there are some interesting deviations from the original Fuzz Face... the most interesting is the 220 ohm resistor coupled with a total of 660uF in capacitors on the first transistor. I assume it stabilizes the transistor, but the capacitance has to be to stop oscillating (it doesn't have to, it's just the way I'm thinking.)
Deletewell thanks for your reply michael i,ll do some research as you suggest
ReplyDeleteHey fuzzhead, interested in doing the Lovepedal Tchula Boost, looks stupid simple...
ReplyDeletehttp://3.bp.blogspot.com/-8yh0reSbQE4/WqfZvfh0SeI/AAAAAAAAF88/Sp8cHZw4cOUb0zetJFn_07vRh1_1VIzogCK4BGAYYCw/s1600/Screen%2BShot%2B2018-03-13%2Bat%2B9.57.59%2BAM.png
Superb pedal, if its not yet verified it is now. Cheers Anders
ReplyDeleteThanks Ian! I'll tag it.
DeleteShould level 3 and tone 2 connect instead?
ReplyDeleteYes, thats correct. layout is updated.
DeleteAwesome. Thanks for double checking. It worked the first way but the schematic I came across when looking for bias voltages was different. Thanks for everything you do buddy!
DeleteHere it is!
ReplyDeletehttps://youtu.be/bZzd8a63Cto
Hi!I built it and works great with an OC71 (low hfe though).How are the trimmers supposed to be set?
ReplyDeleteThis is a really nice boost. Would it be possible to have the Diaz boost up too? A simple one, but nice to have on the site.
ReplyDelete