Acoustic 360 Bass Fuzz

I love the sound of fuzz bass. But as a bass player, it sometimes seems like I’ve been on an endless quest for a great sounding bass fuzz circuit. I’ve tried quite a few different ones, both commercial and DIY, and the one that I keep coming back to is the fuzz channel from the classic Acoustic 360 Bass Preamp.
Acoustic 360 Bass FuzzOver the years, I’ve built a number of different versions of the Acoustic 360 Bass Fuzz, always adding some additional tweaks and modifications to the next one to make it sound progressively better to my ears. And so, I’ve always had some version of the Acoustic 360 Bass Fuzz on my bass pedalboard. But, I think I might have finally gotten to the point where I just don’t need to tinker with it anymore. This may be my final revision of the Acoustic 360 Bass Fuzz.

The factory schematic for the Acoustic 360 Bass Preamp is widely available on the internet. Here is the detail of the original stock fuzz section.
Acoustic 360 FuzzAnd here is my current tweaked, modified and revised version.
moosapotamus 360 bass fuzz schematicCompared to the original, I’ve added a clean blend circuit based on the EH Mole/Hog’s Foot, a decay control that let’s you dial in short, gated fuzz sounds, and I either eliminated or adjusted a few component values to make the circuit sound better when powered at 9 volts instead of the 24 volts that was used in the original circuit.

Speaking of sound, here’s a short video that illustrates how it works and sounds.

Here’s some construction documentation if you would like to build your own Three-Sixty Bass Fuzz from scratch.

You can purchase factory-made PCBs and pedals (hand made by me!) over on my THINGS page.

More videos:

Additional sound clips:

15 thoughts on “Acoustic 360 Bass Fuzz

  1. Doesn’t that clean amp’s low input impedance load down the bass? A 43k resistor in parallel with the transistor’s input resistance (39k assuming a beta of 100) is pretty low for a magnetic pickup.I know it’s not as critical as with a guitar, but it still seems pretty extreme. Or is the muddy sound part of the fuzz sound? Do you run this straight from a bass, or is it buffered? (or is it an active bass?)

    • The clean amp is designed to filter highs and provide a way to blend clean low end with the fuzz. It loads down the bass a bit, but it sounds great mixed with the fuzz, especially at high Attack settings. I plug my passive bass right into it, just like I would with any other stompbox. 🙂

    • Unfortunately, I do not have the free time to build pedals right now (that could change in a year or two, maybe). But you can buy a PCB on the Things Page and find someone with the skills and the time to build one for you.

  2. Hi I notice C12 and C14 are shown as polarised electrolytics in the scematic but in the images are not. I take it the board is correct?

  3. Hi, this 1 interest me a lot. i will have my local pedal builder to build this for me. By any chance, is there any replacement or alternative for 2n5210 and 2n1306 transistor? as far i know, quite hard to get those transistor in Indonesia. Thank you in advance

    • I have never used any other transistors, but I’m sure you can google suggested replacements. The 2N5210 is silicon (Si) and the 2N1306 is germanium (Ge). Best of luck!

  4. Hi! Excuse me for not posting at appropriate page, but Fat’n’pretty page doesn’t have comments, so I must ask you here: what is capacity of C1 – 47p, 470p or 470n? It is labeled as 0.47p, but as far as I know so small capacitors are not available.

  5. Greetings, thank you for the deal that you are doing and I am sorry for my english, I’m from Russia;)
    Prompt, power on the resistor circuit is not specified. Is it enough to use the capacity of 0.25 watt resistors? Particularly interested in the power of resistors R14, R21 of 100 ohms, R10 and R4 150 Ohm 390 Ohm.
    Thank you!

  6. Hi
    Nice work.
    Is there a reason why you changed the polarity of C12 in your schematic compared to the original circuit?
    Thanks for your reply

  7. Hello and, first of all, thank you for sharing this beauty!
    I’m new at this and I’ve been gathering the components to try and assemble this great sounding pedal for a while, now. Yet I have a few questions/difficulties, and sorry in advance if any/all these are dumb questions:

    1.1 – C7, C10, C11, C13 and C15 are they ceramic?
    1.2 – And the six 0,1uF, are they polyesther? (I’m unable to identify the material/type via schematic… I’m either missing something or the difference is negligible, wich one is it?)
    1.3 – C11 is proving to be very hard to find at that value where I am. Can it be changed for a slightly different value? If so, is it better to go 2,2nF or 2.7nF? Or a 2.4nF polystyrene?
    1.4 – It’s mentioned here in the comments that C12 and C14 are electrolytic, but by looking at the PCB drawing and the open back pedal photo, they seem to be more like polyester or something like that. (again) Is there a big difference? And, if there is, what type are they?
    1.5 – C1, C4 and C16 are the ones that look (to me) electrolytic, easier to identify both in the PCB drawing and in the photo. Is this correct?

    2 – Components wattage and voltage maximum limits, are there any recommendations? E.g.: Is it possible to use 0,6W resistors and 15V capacitors, or is there any threshold I shouldn’t go below?

    3 – Similarly to the capacitors above, I ask what type of resistors were used? Metal film, metal oxide, carbon? And again, is that going to intefere noticeably in the end result?

    4 – Q3 is also very hard to find, Even equivalents… is an “equivalent” acceptable for that one part? I’ve been looking at NKT736 because it’s the most alike, specs wiise, but NTE101 keeps coming up on searches…

    Well sorry for the big block of text, everyone, but I’d really appreciate the help of someone more experienced. Thanks, to Charlie and to everyone else, too. Cheers!

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