Hairy Elephant

PSM_V16_D813_The_mammoth_or_hairy_elephantThe Hairy Elephant is a fuzz based on a very similarly named pedal. Its controls are: Volume, Tone, Hair, and Pinch. I built it in search of that buzzed out, right in your face, can’t be ignored, fuzz sound à la QOTSA or Jack White on Lazaretto. It gets pretty close, and can almost sound like a torn speaker. There’s heaps of bottom end (works well on bass too apparently), and with the ‘Tone’ cranked there seems to be more top end than my Fuzz Factory too. The ‘Hair’ knob controls the amount of fuzz, and ‘Pinch’ lets you get that gated chop – and can go from very aggressive sounding single notes to that 8-bit gated sound.

I’m pretty happy with how these turned out.

They sound great, and I think my builds are getting neater.


I built two of them simultaneously (based on this layout). I prepared, populated and soldered both boards, drilled holes in both the enclosures, added all the off-board stuff (pots, jacks, foot-switch, LED, etc…), wired them both up, and finished them off with a nice sticker for the bottom. It wasn’t really much more work than just building one. Maybe what I’ll do in the future to try and fund this DIY addiction, is build two of everything and chuck the second one up on eBay. Both of these pedals are accounted for this time though: one for me, and one for the other guitarist in my band, Mitch.


Fuzz Factory clone #2

ffBecause I love my first Fuzz Factory clone so much, I decided to make another one. The aim of this build was to be a lot neater and to make it as sturdy as I can so that it is more “gig ready“. It’s gotta handle touring and having beer spilled on it. I used the Madbean Zombii v5 PCB rather than Vero this time, and put it in the same size enclosure that the original Z. Vex ones come in. I scored a couple of NKT-275 Transistors from the guy who etched the board for me (I haven’t got the gear for that), and they sound great. They seem to be a lot smoother than the AC128’s in my other build.

This is probably my favourite pedal so far, and it lives happily on my gigging pedal board.

Digitech XP100 to XP300 Mod

OLYMPUS DIGITAL CAMERAIn the 1990s, Digitech created a series of effects called the XP series.

It was made up of the:

  • XP-100 Whammy/Wah
  • XP-200 Modulator
  • XP-300 Space Station
  • XP-400 Reverberator

I picked up an XP-100 back in the day when I was right into Rage Against the Machine (still am…) for the Whammy octave up effect. Very cool. The XP-300 is also apparently pretty awesome too, and is one of the more sort-after effects. Anyway, it turns out that there is not much difference at all between the pedals in the range. They all use the same enclosure (just painted different colours) and they all have the same circuit board (plus or minus a few components here and there).

This means that it is possible to turn any XP pedal into any other XP pedal – or turn one XP pedal into ALL of them! So, I though I’d have a go at modding my XP-100 to also be an XP-300 (with heaps of help from the people at

Here is my XP-100 completely stock, before doing anything:



The ‘software’ for the XP-100 lives on a chip on the board, so to have other XPs living there too, I needed to install a socket for an EPROM chip (circled in blue below). I bought an 27C256 EPROM and one of the nice guys from copied the software on it for me. Next, because the XP-300 is so awesome, it requires more RAM to operate, so I had to install some sockets for extra RAM (circled in red below). The RAM chips are D41464C which I found on eBay. Next I had to install a little 74HC574 (circled in green), which was a bit tricky because it was a tiny SMD IC. Lastly, I removed R38, a tiny SMD resistor (circled in orange).

IMG_4241 - Copy


Here it is, half way there… You can see in this pic I’ve also done the “Output Volume Mod” – it’s a nice easy mod that lets your turn down the output to match your other pedals. It’s just a dual-gang pot connected to the output jacks.



Now it’s just a matter of installing the switch. The switch tells the XP which mode to boot up in. If it is one way, it boots up from the onboard XP-100 chip, if it is the other way, it boots up as whatever is on the EPROM – in my case, it’s an XP-300. The switch has an 100 ohm resistor in the centre pole connected to the hole directly above the “33” marking, and right next to the lower pad of where R38 used to be – this is my blue wire. One side of the switch connects to the hole just to the left of the “U8” marking (my green wire), and the other wire goes to ground (my red wire). Like so:



Job done!

To change modes, just disconnect the power, flick the switch, and power it up again.

So now I have the Whammy/Wah and the crazy Space Station all in one box!


For more info, and a way better understanding and explanation than I can give, check out this thread at and also this awesome documentation: converting-the-digitech-xp.pdf. It talks about creating an “XP-ALL” which is all the XP effects in one… that might be my next challenge…