Servo Fuzz Face

[Chuck D. Bones]

If someone puts it on the Wishlist there's a good chance. I am too modest to put my own creations on the Wishlist.

 

[jubal81]

Well, I just ordered 4 pcbs from pedalpcb and have an upcoming exam and possible international move. So I am guessing about 3-4 months before I would be wanting to start any further pedals. Would it be conceivable this project might be become available as a PCB on the site in that time ??

You can give it an upvote on the wish list.

 

[Preverb]

You can give it an upvote on the wish list.

Done!

 

[Preverb]

Could this design be partially used for other germanium based fuzzes and boosts?

 

[Chuck D. Bones]

The concept can be applied to other Ge-based pedals, but the details will depend on the particular circuit.

Not every Ge circuit needs bias stabilization. Hybrid circuits like the Skreddy Screw Driver and the BJFe Pink Purple Fuzz are very stable with temperature.

 

[Robert]

Would it be conceivable this project might be become available as a PCB on the site in that time ??

We'll have us a good ole Boneyard Binge pretty soon.

 

[fig]

We'll have us a good ole Boneyard Binge pretty soon.

Indeed.

 

[benny_profane]

We'll have us a good ole Boneyard Binge pretty soon.

They did the monster mash. It was a boneyard smash!

 

[fig]

In time for a hauntingly groovy giveaway?
A Turkey-Day contest?
Santa's sack?
Happy New Year!
Man, where has the time gone?
And where is that board we were talking about back in October?

 

[Chuck D. Bones]

Which board would that be? I have so many irons in the fire, it's hard to keep track.
ADHD? Nawwww, I'm just easily distracted. Ooooh, shiny!

 

[bhcarpenter]

Please excuse my ignorance, but would it be possible to use this biasing scheme for the Sandspur Fuzz by substituting the circled sections? I’m envisioning a footswitch mounted daughter board.

 

[Chuck D. Bones]

Yes, but you don't need it. The whole point of the bias servo is to stabilize a germanium FF. BC108 is silicon, so it doesn't drift much with temperature. If you do decide to try it anyway, plan on reducing R9 to 2.2K

 

[bhcarpenter]

Awesome! I guess the PNP version would look like this?

 

[Chuck D. Bones]

Close, but no cigar. You have return the FUZZ pot to +9V. R7 in my circuit is equivalent to the FUZZ pot in the Sunflower. There are some other details to attend to as well. It's a little more than cut & paste.

 

[Preverb]

Is this one any closer to becoming a PCB here? Have been waiting for this one

 

[szukalski]

Someone may have been working on the PNP version after seeing that wishlist bumped:

 

[Chuck D. Bones]

If you're going to put the 100uF cap that far away from the CA3130, then you need to add a 100nF cap from +9V to GND right next to the CA3130. Opamps, especially CMOS opamps, need power supply bypassing right at the chip to prevent oscillation.

Did you really ground pin 7 of the CA3130? That's Vcc, ya know.

 

[cooder]

Yes it's killa Fuzz, has a firm first spot on my board. So tweakable and great sounding, lovin' it!
Here's my PNP version:

 

[szukalski]

Good catch on the 100uF. I had it aligned next to the IC when I was grouping components but then it popped out when I was arranging stuff. I’ll give the layout another round.

Pin 7 is on Vcc. I have a ground plane and Vcc plane.

 

[Chuck D. Bones]

Ok, that's good. How many layers?