Monday, 28 May 2018

Pigtronix Fat Drive

Original info:
"Pigtronix FAT Drive takes a futuristic analog approach to create complex crunch tones using CMOS clipping and a variable low pass filter for tone shaping. Bringing the tone control all the way clockwise takes this filter completely out of the circuit for total transparency and robust low end. Rolling the tone control back smooths out the highs, leaving ample mid-range bloom and bottom end punch.
A Hi / Lo toggle switch brings additional versatility to the FAT Drive’s wide-ranging palette of overdrive tones, altering the gain structure for enhanced crunch and soaring leads. The FAT Drive features true bypass switching and runs fine on standard 9-volt power but ships with an 18-volt adapter for superior headroom, clarity and overall output"
Schematic available here.


  1. Thank you Alex and everyone involved with this one.I bought the pedal for $35 can't wait to build this circuit and compare them.I appreciate all the time and hard work that goes into making up a vero or reverse engineering a circuit for a schematic.I started to R E this one for the schematic but it was posted up befor i could finish it.Now i have a lot more respect and appreciation for what all you guys do on here.thank you

  2. Terimakasih atas informasinya, Silahkan Kunjungi website kami ^^
    Fauzia Herbal

  3. wihh nice info
    kunjung balik, di web kami banyak penawaran dan tips tentang kesehatan
    Ada artikel menarik tentang obat tradisional yang mampu menyembuhkan penyakit berat, cek yuk
    Obat Tradisional Hiperdrosis, penyakit berkeringat berlebihan tanpa sebab

  4. sorry for offtop (just dont know where to ask). i am not "guru" in Muffs. i like "wren cuff eye see 78" (its op-amp big muff). which schematic should i use for that "smashing pumpkins" sound/tone? (which one is better)

    1. Hey there, it's just this one:

    2. can i use ba4558 Op-Amp for that?

    3. (yes, and thank you, ofcourse)

    4. Sorry for the late reply mate. You should be fine. The BA part just tells you the manufacturer of the chip. As long as it's 4558, your good to go.There are several manufacturers, such as RC 4558, NJM 4558 or BA 4558.
      In theory any dual op amp with the same pinout would fit but give slightly different results (TL072 NE5532 OPA2134, etc)

  5. Hi all! Just waiting for some parts before I slap this together. I’ve done the once-over on the layout and I suspect the bridge next to the 8 cuts for the 4049 needs to extend one row north... as it is, it moves from pin 7 to pin 11 (input to input) and pin 6 (the output) goes nowhere.
    Thanks for the layout Alex, I can’t wait to hear this working.

  6. Verified! Haven’t played with it much yet, but definitely delivers what it promises.