Mozrite Fuzzrite build and report with pics

[Barcode80]

So, I've built my second successful project. I have actually built more, but the ones i consider successful are the ones that fire up and sound exactly right, and some of mine don't yet

here are pics:


Dim picture to show LED lit up

Da guts

shows color better

I used a RACO enclosure, one of the ones I posted as an empty shell in the pictures thread. The sound of this pedal is GREAT!!! My only substitution was I used a 1 Meg pot instead of 500k. I used Dragonfly's perf layout, It is superb.

I do have some changes in mind already. The perf is way bigger than necessary for this layout, so I may trim it down. I need to find the source of some radio interference coming through the signal. I may switch enclosures, as the paint got a little messed up (beginner's tip, don't paint before drilling ) I also need a more permanent mount for the LED, I just have it poked through with no bezel. I don't like bezels, so, I will probably secure it in the back with silicon. I also need to tidy up the wiring and shorten some leads (could be the reason for the interference?). Let me know what you guys think!

EDIT: sorry about the fuzzy pics, I'm having trouble with my camera taking closeups!

[petemoore]

  Cool, I got a funny Mosrite schematic [iirc] and never could get it to pass signal.
  Congratulations !!

[doug deeper]

ahhh
my all time favorite fuzzzzzzzzzzzzzzzzzzz
looks good!

[Barcode80]

okay, i haven't had a chance to shorten leads and such, but i changed the enclosure and cleaned up the look a little, topped off with a pair of shiny chrome knobs. here are pics:





The circuit is hidden by that big black foam pad, used to protect from ground-outs


What do you guys think?

[Dragonfly]

VERY COOL !!!   congrats on a successful build !

re: radio interference....its fairly common in high gain circuits ...usually putting a 1k-10k resistor on the input of the effect will quiet it...

AC

[brett]

Hi
nice result.

My only substitution was I used a 1 Meg pot instead of 500k.

The original schematic calls for a 350k fuzz pot and IIRC a 33k volume pot.  These values are important because they affect the bass output.  It might be best to keep the total impedance of the two pots somewhere near the original. 
I used a 250k fuzz pot and a 100k volume pot.  The result is very limited bass fuzz (the low E string is very weak).  The tone of mine is somewhat like the brassy fuzz you hear on "Satisfaction".  I think the cutoff frequency is just above low A (250 Hz).

A 500k fuzz pot will let a bit more bass through (cutoff about low E), and a 1M will probably let everything thru (cutoff down at 50 Hz like most pedals).
It's certainly a simple and fantastic circuit, that's for sure.

PS the radio pickup might be due to using high hFE transistors.  The originals would have had hFE about 150.  I used BD139s with great success.
cheers

[reverberation66]

      looks good, I like the square yellow version.  Raco boxes make the bet enclosures if you need something cheap and solid, those things are freakin' heavy duty.  Nice job, yay for perf wiring!!!

[Barcode80]

okay, upon listening on my full tube rig, this thing sounded blatty as hell. so i checked voltages and i'm only getting the following:

Q1
E - 0
B - .53
C - .59

Q2
E - 0
B - 4.76
C - 4.76

I am pretty sure this is flat out wacky. These can't be correct can they?

[brett]

Hi
Q2 is wrong.
Check the bias resistor (470k) from the collector.
The base should be 0.6V above the collector (in all audio NPN silicon transistors, always).
cheers