My Newest Fuzz Project

[italianguy63]

Probably ho-hum to a lot of you guys but pretty cool to me..

Finally got around to ordering some new boards for me to play with.  Basic PNP Fuzz Face.

With charge-pumped power (to daisy chain), ring noise isolation circuit, LED power, & ground pads for using shielded signal wires.
Options for:  Power sag, treble bleed, onboard or user controlled transistor bias.  (in any combination)




MC

[lungdart]

Did you design these boards, or are they part of kit? Also would love to see the schematic.

[italianguy63]

Designed it with help from folks around here.  Learned to use "Eagle" to design it, and I use EleCrow for my PCBs.  Schematic is kind of funny because I had to draw it psycho to get the multi-options.. so several things in duplicate depending on which pieces you use!  MC  p.s.  it has a pretty small footprint too...

[mmlee]

If you have any spare PCBs I'd be interested. Looks like a nice tidy board.

[italianguy63]

No problem-- I will have some extra.  When they come in and I know they work-- just cover my cost...

Thanks, BTW-- A lot of time, thought and effort here.

 MC

[italianguy63]

Manufactured, and on the boat from China.  Should see the finished product in about a week.   

[haveyouseenhim]

Looks like a fun project. I have had a set of fuzz face germs for a year and haven't used em.

[italianguy63]

I'll toss you one when I know they work as designed... 

[italianguy63]

OMG... Waiting on the worms.  Feels like forever....

Still not here.  I know they exist.  I saw pictures.

MC

[Tony Forestiere]

OMG... Waiting on the worms.  Feels like forever....

Still not here.  I know they exist.  I saw pictures.

MC

Just keep humming a certain Tom Petty song in your head. 

[italianguy63]

Looks like tomorrow night if I can make it to USPS before the close on the way home from work!   

[Mbas974]

you mean this service  ?

http://www.elecrow.com/services-c-73/pcb-fabricate-service-c-73_116/

[italianguy63]

Yes-- that is who I use.

[IsaacMoth]

Looks really good man. i always forget mounting holes!

[italianguy63]

Thanks!!  The boards came out awesome.  I found an error in it last night; luckily it is minor-- I created it trying to be too clever aesthetically.  Ran a short trace to the wrong side of the paralleled bias circuits.  Luckily, an easy fix by altering the bias pot wiring slightly.  So, no biggie, and I will fix it in the build document for now.  I'll fix it on "Rev. B" (if I need a Rev. B).

Give me a couple days to build one out, and then I will send out the handful of promised boards to my guinea pig builders...  

Just report back to me what you think.

I'll post some pictures soon.  This thing is awesome small and tight.

MC

[italianguy63]

Coming Soon!

Prototype is going to be a 5-knob to check out all the bells and whistles:  Level, Fuzz, Bias, Sag, and Treble Bleed.

[artemijs]

Cool! Do you have demo?

[italianguy63]

Not yet.  But I will be working on that.  I have a buddy working on one for another Fuzz I did.  Still waiting on that video.   

[italianguy63]

Semi-update.

I have been out of town for a few days, so I really haven't been able to work through things.  But I built a proto, and it has some issues.  Nothing horrible I suppose, but will take some time to work through.  Seems this proposed build has been cursed!  Nothing has been easy.  Issues listed:

1.  RG's signal switching jack trick acting funky... not letting power through.  Sounds like a quiet jet engine starting-- capacitor filling.  Eventually it will let power in.  And, shorting the base to the collector of the 2N3906 will instantly "jump start" it.  Makes me wonder if the filter cap behind may be too large?  100uF.  What would cause this?

2.  Sag control not acting like it is working.  Checked it.  It is wired right, but the pot is not limiting voltage like it should.  I took the pot out of the circuit and checked the resistance, and it checks out OK.  Makes me think the pot is faulty.  I'll have to take it off the PCB again.  (update, seems fine.. maybe I was just too tired).

3.  Was not getting adequate signal (fuzz).  I have been experimenting with some Russian GT trannies.  I did one pedal and it is fine, but 3 after have not worked.  The common denominater is the trannies.  I think they just don't have enough gain to get it done.  I took the GT's out, and threw in some GE's (2N's) and they worked.  More testing required.

4.  Had problems with the Treble Bleed and Bias pots.  Scrapped it and built a simplied version.  It is working other than the listed issues.  I think my problems may be related to #3 above.  The onboard bias works.  But the pot on the other wasn't.  Yep, more troubleshooting needed.  The treble bleed just didn't seem to do anything, but with all the other issues, it just needs another look.

No rest for the wicked.

MC

[italianguy63]

Hey R.G.!  Per #1 above-- Any idea why the 2N3906 is having trouble engaging in this circuit?:



I am considering lowering the value of C1.  I can hear a faint sound of a cap "filling"  (long rising tone)....