Stuck on Superfuzz build

[greenacarina]

I just finished soldering all my components to my Superfuzz PCB (which is a good thing!). I used this as my layout reference- http://members.fortunecity.com/uzzfay/superfuzz1/sfbrdptmk.html

Now I'm trying to figure out where to wire in my pots, so I refer to this schematic- http://www.geocities.com/CollegePark/Library/1355/superfuzz.gif

Now, is it just me or are there vastly different resistor values between these two? Which Superfuzz is "correct" or more true to the original?? I'm a big Mudhoney fan, so I GOTTA know!! 
Chris

[greenacarina]

Certainly someone must know what's what here?? 

[slacker]

I can only see one resistor that's different on the layout compared with the schematic. That's the 150k on the PCB layout which is 270k on the schematic. The only other difference is the .001uF capacitor in parallel with the 47k resistor between +9 and the collector of the first transistor, which is on the layout but not the schematic.

[greenacarina]

I can only see one resistor that's different on the layout compared with the schematic. That's the 150k on the PCB layout which is 270k on the schematic. The only other difference is the .001uF capacitor in parallel with the 47k resistor between +9 and the collector of the first transistor, which is on the layout but not the schematic.

OK, I squinted a little harder at things and got it all figured out. There are a couple holes where holes shouldn't be, and it looks like the 10k and 22k resistors for the "notch" portion are reversed. I copied that layout image into Photoshop and labeled everything for easier reference. So regarding the swap of the 150k and 270k resistors....what is the function of that particular resistor?? I'm wondering if I should use 150k or 270k?

Chris

[Barcode80]

keep in mind that sometimes on pcb layouts extra pads are added to accommodate possible and recommended mods. check the supplier's site for such things...

[Dan N]

I should mention, one of the electrolytic caps on that fuzz was reversed. The fuzz still sounded great, but every now and again I get an email scolding me for showing it as it is instead of how it should be. So, try reversing the cap connected to the collectors of the differential pair and be happy.

That 150K is the same on several other superfuzzes I have seen, so I'd go with that value.

Man, fortunecity really sucks.

[greenacarina]

I should mention, one of the electrolytic caps on that fuzz was reversed. The fuzz still sounded great, but every now and again I get an email scolding me for showing it as it is instead of how it should be. So, try reversing the cap connected to the collectors of the differential pair and be happy.

That 150K is the same on several other superfuzzes I have seen, so I'd go with that value.

Man, fortunecity really sucks.

OK, I found that cap that was reversed...but I also found a few other things. Now, keep in mind I'm very much a newbie and learning as I go so please don't interpret anything coming from me as nitpicky or ungrateful. I appreciate everyone's efforts in providing all this information as it's given me countless hours of enjoyment and education! With that said, here are the notes I've made thusfar-


I am guessing that a schematic or PCB layout is transcribed directly from a commercially-made pedal at some point, so I don't know if this layout is more "correct" than Philpott's schematic or if these things really make any difference at all. I'm just asking because otherwise I will never learn.
Thanks!
Chris

[Dan N]

Ha! You did find one! That cap off the base center leftish is the other way around on my Companion small box SF.

The 10uf cap from hot to ground is correct, but 100uf would be fine and dandy,

The 22K and 10K resistors in the filter are the same in my Companion. I doubt if switching them would make any differnce. Go wild and try both ways!

Don't mess with the bias resistors on the differential pair! Both bases have 100K up and 22K down. You could lift those 22K from ground, connect them to opposite ends of a 10K pot with the wiper to ground, and have a way to really dial in the best octave tone.

Hope your fuzz turns out great!

[greenacarina]

Well, here's what has me asking all these questions-


So, it sounds like these things are incorrect and I'm better off following the PCB layout??

[Dan N]

With all due respect to Justin, the 22K/100K stuff is an error.

The box he traces may very well have had the other parts as drawn. 100uf PS filtering would not affect tone, and would be nice when using the odd wallwart.

The resistors in the filter are as per the layout in both the small box Companion and the big box Orange/Blue fuzzes sitting in front of me. I pretty much trust the Companion as the last word in good sounding SF's!

Hope this helps!

[slacker]

Here's another superfuzz schematic, that I think matches your PCB layout.
http://www.univox.org/pics/schematics/superfuzz.gif

[royzic]

hey greenacarina

the schematic slacker posted is correct.
it is the unicord superfuzz though,to build it stock you would want to take out the 10k pot and ground the two 22k resistors .

roy