First Pedal Build - BYOC ESV Fuzz

[Fresh_Start]

Just finished an ESV Fuzz - my first pedal build.  I understand tube circuits reasonably well but don't know much about solid state devices.  During this build, I forgot a couple of fundamental rules I learned long ago while building and fixing amps:

1) Plan to be wrong about something!
(big surprise - PRR is still correct)

2) If something can move while you're soldering it, it will move and you'll get a bad solder joint

3) While debugging, only try to fix one thing at a time.  Otherwise you won't know what fixed the problem and/or created a new one.

4) Just because it's a "simple" circuit inside a little box doesn't mean that you can rush through it

When I had the pedal squared away, I started experimenting with my Strat.  Cool & very familiar sound  :D Then I switched over to my Heritage 535 equipped with Seymour Duncan Antiquity humbuckers.  Yee hah!  THAT'S a whole lot of fun.  What could I switch in the circuit to get that same totally saturated fuzz with single coils?

I've looked for Fuzz Face mods all over, but there are sooo many!  This looks like a pretty cool collection, but I don't know if any of them address my question about a single coil/humbucker switch:


You can find the schematic for this circuit on page 16 HERE

I've noticed another odd difference between the Strat and the 535.  When I turn the volume down just a touch off 10 on the 535, there's a abrupt drop in volume with the Fuzz engaged.  Effect is smooth with the Strat.

Also, I'm confused about the Fuzz and how it interacts with my Strat.  I've got a series/parallel switch.  Normally, parallel is lower volume and sweeter - typical Strat tone (don't know why they call it "quack" but whatever) - and heavier, more humbucker-like when 2 or 3 coils are in series.  With the Fuzz engaged, the parallel setting is louder and more raw.  Series seems a bit muffled and definitely lower output.  What the heck is up with that?

Cheers,

Chip

[thelonious]

I've only built two pedals so far and don't know that much about solid state either, so I'm sure someone else could give you a more involved answer. But - how much have you experimented with the bias pot? I'm wondering if that might help bring more consistency to the sound by altering the bias on the transistors.

In terms of getting that thick, saturated sound with the single coils, you could using a fat boost compressor to drive the ESV harder when you use your Strat. I built this: http://radiate.aplacetoconnect.com/2011/06/30/first-compressor-build/ and found it to really fatten up single coils well. I found the 15n input cap to be too much, so I used a 6.8n instead, but YMMV.

No clue on the series/parallel issue. That's just weird. 

[Fresh_Start]

Like I said, I don't understand much about solid state electronics.  I've read that a Fuzz Face like this does better before any buffering but don't know any more than that.

Experimenting with the bias pot is essential.  The silicon "test transistors" that came with the kit like a different setting from the germanium AC127 (NPN) transistors sweet spot.

Here's the Boutique Fuzz Face (late '60s version) from General Guitar Gadgets:
http://www.generalguitargadgets.com/pdf/ggg_ff5_sc_b69.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

Apparently the "Contour" control and the 50K "R7" (mis-labelled "Bias" - should be "Cleanup") are kind of yin & yang - Contour affects output level and R7 reduces input level.

I can't stop fooling around with this little box!  Guitar tone, volume setting, and of course the volume and fuzz controls on the box are all more interactive than the dirt boxes I've messed around with before.  Big fun!  

Cheers,

Chip

[Platefire]

Kool project Chip.

I've been having a hankering for a two stage distortion with two switches. So the clean on your amp would be your clean then the first stage distortion overdrive and the other stage higher gain distortion. There are several comercial boxes--I guess that type would be too complex to start off with if you never built a pedal. Don't even know if they make a kit for one like that? I'm like you, don't know hardly anything about solid state. Plartefire

[Fresh_Start]

Platefire - You can handle THIS no problem!  BYOC's "Overdrive 2" is a Tubescreamer with a separate clean boost post overdrive.

Building from one of these kits isn't much harder than some of the model rockets, cars and airplanes I built as a kid.The catch is that when you're working with a PCB, modifying the circuit can be a challenge to say the least.  The MOSFET options on this one look really cool BTW.

Cheers,

Chip

[Platefire]

Hay thanks. That looks good. If I read the details right, the clean boost could be modified into a type of overdrive? I've never had much use for a clean boost. Platefire

[Fresh_Start]

As a follow up, I discovered that the bass-cut control on another Strat-like guitar cuts the fuzz dramatically (and not in a good way) if I turn it just a smidgeon away from "10".

The guitar schematic is based on the G&L Legacy except, being me, I added a couple of switches.  Here's the G&L schematic:
http://www.glguitars.com/schematics/Legacy_schematic_blockdiagram.pdf

I've attached my old drawing of the guitar wiring.  It's kind of like Doug's "schemat-out" for amps.

This effect seems to have everything to do with the output impedance of the guitar versus the very low input impedance of the fuzz pedal.  I'm rapidly coming to the conclusion that the Fuzz Face circuit is what it is and as soon as you start trying to "fix" its "defects" you lose the Mojo. 

Cheers,

Chip