Woohoo! I got the YAFF working at last!

Started by mrmrcoleman, December 01, 2005, 03:18:05 PM

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mrmrcoleman

It's working!  :icon_cool:

Thats my first pedal done! It's taken almost 10 days but it does actually work.

I can't believe the bad luck I have had, first my multimeter broke, then I found out that the breadboard had dodgy connections too. Anyway, replaced them both and it is working nicely.

Only a couple of problems:

1. When the fuzz is at minimum the sound isn't quite clean.
2. The fuzz itself sounds very grainy, and bitty, like the sound is breaking up.

To fine tune the fuzz should I put a variable resistor in at the collector of Q2, i.e. instead of R3?

Also, the sound has a lot of bass in that I don't like, it sounds TOO beefy, is this altered with the output cap C3?

Thanks for any help with these questions, and thanks for everyones help throughout.

Mark

MartyMart

WELL DONE !!  and welcome to the "club"  :D
Now you're hooked eh ?

I/O caps can "thin things" a bit, you could make the large 2u2
a much smaller 0.1uf poly cap ....
And as I said earlier, a 10k trimpot to Q2 will set the bias WAY better
than a fixed resistor and also let you try some other NPN's in there too !

Marty.
"Success is the ability to go from one failure to another with no loss of enthusiasm"
My Website www.martinlister.com

petemoore

1. When the fuzz is at minimum the sound isn't quite clean. "FF'...not called 'clean face' though IIRC there is one derivitave FF called that. I like the pregain fuzz pot on the box or in the guitar, the guitar volume. Both are variable resistive dividers, having one in the box is nice exp. if you use Humbuckers, I think they mud up at Full Output, I like 'em better backed off a hair, pregain in the box makes the max input gain easy to set on the guitar...all the way up for Thick Fuzz and less 'mud'.
2. The fuzz itself sounds very grainy, and bitty, like the sound is breaking up.
 
To fine tune the fuzz should I put a variable resistor in at the collector of Q2, i.e. instead of R3? You're on the right track, Diddle with Q2CR value and you'll see this probably answers Question #2.
  My FF's all sound different through different amps, Sounding rather great or lousy, depending...

Also, the sound has a lot of bass in that I don't like, it sounds TOO beefy, is this altered with the output cap C3?
Convention creates following, following creates convention.

petemoore

  Here's something about caps
  They pass HF, cut low Frequencies.
  If the signal path is passing through them [like the input and output caps of the FF] they are High Pass Filters [HP Filters], depending on the value of the cap used, they will begin decreasing the amplitude of 'bass' [lower freq's] and Pass the highs unattenuated.
  DC is 'no frequency' at all, caps contain the DC for powering the transistors within the circuit, these are the input and output caps.
  Conversly a cap connect FROM signal path to ground allow HF's to be 'shunted' [connected to ground FPODiscussion],  but allowing the Low Frequecies to pass..a High Pass Filter [HP filter]  ['rolloff' is the curve on a chart that shows how the amplitude is increasingly cut as freq's get lower and lower]
  So caps pass higher freqs, and depending on if they're series in the Signal Path, or Signal path to ground, they can be used as HP or LP filters....adjust values as necessary.
Convention creates following, following creates convention.


guitar_199

Congratulation mrmrcoleman.   It all gets easier as you go.

Well.....sometimes.........

Occasionally anyway!

Really!!!!!!!!

;)

mrmrcoleman

Well thanks for all the feedback guys, I am going to go and purchase some variable resisitors and some different value capacitors and see what I can get.

Also, I am using a PN2369 and a BD109 at the moment, would it make much difference if I swapped these around or tried two of the same together, or does this not really affect the sound?

Mark

stm

Quote from: mrmrcoleman on December 01, 2005, 03:18:05 PM
It's working!  :icon_cool:

Thats my first pedal done! It's taken almost 10 days but it does actually work.

I can't believe the bad luck I have had, first my multimeter broke, then I found out that the breadboard had dodgy connections too. Anyway, replaced them both and it is working nicely.

Congratulations.  I wouldn't say the FF is an easy pedal to start with--it can be rather "bitchy".  And regarding bad luck, Murphy always does it job!

Try using pots on both collector resistors and adjust them both to find your sweet spot.