Tonights Fuzz Experiment (includes sound clip and schematic !)

[PurpleStrat]

This just might be my second Fuzz build here!

[jayp5150]

That's a killer sounding pedal!

Now you have me blushing....

You should build this one...it's pretty cool...I'm DEFINITELY going to refine and box it up !

The diode in the feedback loop I thought was interesting....I hadnt seen anyone doing that before. Ive run diodes of Q1's emitter, and the old Joe Davisson "Antiquity Fuzz" setup...but never in place of the resistor in the loop.

Actually, I came across that in Tim Escobedo's Many Faces of the Fuzz article a while back. I used a DPDT that has the 100k on one side, and a diode loop on the other. It's an amazing tone.

Here's mine: http://www.freewebs.com/jayp5150/pedalsschemssoundclips.htm

There are two clips there, one with the resistor, and one with the diodes. Mine was more of a classic fuzz, though (oh, it's the Gypsy Beaver one). It's since been tore down and I'm in the process of trying to tweak it a bit further.

I'm not trying to be a buzz kill (I thought that I thought of it, too lol), just didn't want to leave someone out of the credit.

BTW, I'll second that King Of Fuzz thing.

[DougH]

Sounds great, Andy! Fu Manchu would be proud...

This looks like a good candidate for a 1590A.

[petemoore]

  A real Gonker you got there, very disgusting, thank you !
Try this, get it playing in WMplayer, then go to the myspace and get that playing, pause the WDM version occasionally so the two plays are in or out of sync...close your eyes or you may have depth perception problems !!

[culturejam]

Hey DXM (or anyone else):

What's the purpose of the 2n3906 you added to the schem and layout? Something to do with the power supply? And why a PNP in that position?

I've seen something similar in a few other circuits (Octavia and the Fuzz Factory) and wondered what it was for.

Thanks.

[Baktown]

I'm also curious about the PNP on the redrawn schematic.  Since I'm a rank beginner, stuff like this confuses me!

Rick

[Dragonfly]

Looks like a transistor Millenium Bypass....

[Dragonfly]

HEAVY FUZZ SOUND CLIP

[dxm1]

I'm also curious about the PNP on the redrawn schematic.  Since I'm a rank beginner, stuff like this confuses me!

It's basically a power switching scheme based loosely on RG's "Cheap (and Good) Polarity Protection" circuit:

http://www.geofex.com/Article_Folders/cheapgoodprot.htm

Power flows through the PNP transistor when it's base is grounded. This happens when a plug is inserted into the input jack. The 10K resistor keeps the transistor off when the base is not connected.

Normally, the battery ground is wired to the Input Jack ring terminal - with this circuit, the negative battery lead is wired to the normal effect ground.

I like to include the Status LED's current limiting resistor on my circuit boards to reduce the offboard wiring chores.

This circuit is so small and cheap, I use it on nearly all of my builds - so it is included in the blank "template" in my schematic capture program. If you choose not to use it and wire things up in the standard way, connect the battery negative to the Input Jack ring terminal, and the positive power wire to the board where the transistor's collector would be. You could also lose both filter caps (C1 and C2) if you wanted. The LED limiting resistor could be wired offboard as well.

That would save you about 50 cents and 1/2 square inch of board space...

[Dragonfly]

This sounded so good on the breadboard, I decided to commit it to glass.

PCB:

http://home.surewest.net/dxm1/images/vmf_pcb.pdf

Component Placement:

http://home.surewest.net/dxm1/images/vmf_comp.pdf

Schematic:

http://home.surewest.net/dxm1/images/vmf_sch.pdf

Did you get it "boxed up" yet ?
I'm curious to get your thoughts on it....

[Baktown]

Thanks for the explanation!  It makes perfect sense to me, which is kind of scary!  LOL

Rock on!

Rick

[culturejam]

Okay, cool. Thanks for the lesson, dxm!

I'll read the article you linked and see if I can get a deeper understanding.

[PurpleStrat]

I must have done something wrong, I got a clean boost?

[dxm1]

Did you get it "boxed up" yet ?

Gimme a break - I'm still trying to perfect that 'swirl paint' technique... 

I'm curious to get your thoughts on it....

I like it. I'm not a huge fan of silicon fuzzes, so I was surprised with how it reacted with humbuckers. I've never heard a fuzz that exhibited the 'volume knob roll-off' effect with humbucker pickups as well as this, and it doesn't display the typical grainy, screeching silicon sound.

With a Strat it's OK - kinda flabby bass, and not much in the cojones department. That could be tuned. Where it really shines is with P90s. I _really_ like the sound with a little hotter single coil pickup. A little tweaking, and this could be my P90/Slide sound.

I'm not sure the first board I cut will make it to box-dom. I'm currently breadboarding a variant using a GT311 for the second transistor...

[PurpleStrat]

I have gone over this many times and can not find what I did wrong. Here is a pic. The diode is on the back. I have everything wired just like the schematic.

[foxfire]

well without seeing the underside the only thing i can see is the it lloks as though your input cap is backwards. though i'm not sure that would keep it from working.

[PurpleStrat]

The input is a non polar 1uf. Here is the underneath and another pic of the top with lines to show the conections

[Focalized]

I've been trying to make a stripboard layout for this. I've never tried converting a schematic into a layout. It's hard! Can't wrap my head around it. Anyone? Stripboard layout? I want massive fuzzzzzz.

[Baktown]

How does this look?  I realize that it's a little larger than it could have been, but I like to use 4 holes for resistors when possible to I can lay them flat.

Rick

[raulgrell]

It seems you have gone over your bandwidth limit... Any chances you could send me those clips? email : raulgrell at gmail.com