Crawls Backward (When Alarmed)

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Sili-Face II - Redoing Version 1

So I'm back after watching the Canadian GP. Seems that Jenson Button is peaking out! Well done.  Seems that we have actual racing this year.

After the race, I snuck down to the workbench and set to rebuilding the Sili-Face II I had started a while back. I guess I'm just dumb, but I finally figured out that I should approach the vero board layout as if it's an X-ray. That is, the cuts on the strips should be where they should be when the board is facing up. And then the components go on the top side. I originally approached this as you would a PCB in terms of top and bottom, but this approach seems to work.  Again, I may be stoopid, but now I won't put the transistors in backward!

I actually did have the first version of my Sili-Face working after a fashion, but I had some flaky connections, so I just decided to take off what I could salvage (the capacitors and transistors) and build a new one. 

And here you have it, v2.0.  It just fits on the board - I could have used an extra row of holes on one end, but it did fit.  Since it's my first go around, it was a great learning experience.

You can see how compact it is.  The 10K trimmer is the largest component.  The whole thing is smaller than the battery. 

And this is the back side.  The arrows point to 2 of the strip cuts - there are 5 total.  I also read on the interweb that it's best to make the cuts with a small drill bit by hand...and this worked out much cleaner than my first attempt.  One thing I do need to get is some smaller gauge solder so I can make the joints a bit cleaner, but these are adequate.

The fuzz did work first time.  It sounds pretty raspy at the max setting, but it does clean up nicely with the guitar's volume knob.  I snagged some germanium transistors, so one of my next builds will be a PNP build so I can compare the silicon vs. germanium tone for myself.

I have read about a couple of mods that I'm going to try - one is to increase the voltage on the collector of Q1 (the first transistor) from about 1.2 to 4.5 volts.  That just involves changing one resistor value. 

I need to lay out the box for this one, but it's close to being done.  I've never had an actual fuzz pedal - I've had more of sort of overdrives - so this is a different animal for me.  A good project all around.

 
 
 
 

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