Expandotron-ZZ

The original 'boutique' pedal? Maybe. Whatever, this crunch box is capable of some sweet drive.

Famously used by Billy Gibbons (ZZ Top) - it may not get you his tone but it'll point you in the right direction.

The DIP switches of the original have been replaced in the kit by external toggles so you have easy access to all the modes the pedal has to offer - Crunch, Overdrive, Distortion and the whacky Forbidden mode which can be a lot of fun. You could make the switches internal if you can source some 5mm pitch slide switches, but keeping it all outside the box is the order of the day here.

The optocoupler used in the original pedal (PC239) is now obsolete, so we've replaced it with a more easily obtained H11F3. If you can tell the difference you have better ears than ours.

This latest version (Feb '22) incorporates the optional bass mod of the Godlyke reissue which actually works nicely.

The kit is supplied with vertical-mount pots which have round shafts, so you'll need set-screw fitting knobs.

Currently only available with OP07 ICs as we're out of LM308. If you can hear the difference, good luck to you.

If you want the PCB without parts there's a link for that at the bottom of the page.

Partial kit: PCB, all board-mounted components, pots.

Full kit: As above, plus footswitch and appropriate daughterboard/components for your selected bypass type (see Downloads section for details of those), jack sockets, DC socket, battery snap, hook-up wire, LED.

Enclosure (pre-drilled) is available as an option with full kits, and will not take a battery. Knobs are not included.

Inspired by: Expandora

Difficulty: Medium

PCB size: 50 x 50mm

Knobs required: 3

Enclosure: 1590B

Direct-Connect compatible (4-way)

Download the INSTRUCTION PDF

Here's the previous version as there are still some in the wild.

Product Code: Expando

Brand: Pedal Parts

Product Condition: New

Bass toggle* Kit type* Ribbon connector?* Pre-built? (UK only.)*

£50.40 inc. tax

£42.00 ex. tax

? Tax based on United Kingdom.

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Customer Reviews

4 review(s) posted (write review)

So many great sounds from one pedal
"I was recommended an expandora as an all-bases overdrive to fuzz pedal and it is great for that and less niche than I imagined, one of those circuits that makes you smile when you fire it up. The volume pot uses 2 lugs so I rigged a 4pdt with two sets of gain switches and two volume pots to give two channels sharing the gain and tone pot but with two sets of gain switches, each set with its own volume to have two settings on the fly. A weird bonus is that with both gain switches on the lowest setting and the gain pot barely on, you get a great London Calling slight overdrive sound that is much fuller than a clean tone." Joey Chickenskin - 14 August 2024

Special overdrive / distortion pedal
"Very happy I've finally built this. It's really got its own thing going, and to my years it pulls off Thom Yorke's tone on Bodysnatchers convincingly even with my P90-equipped guitar (he's famously using a humbucker SG, but I no longer own any humbucker guitars). Definitely one of the better circuits out there, too bad I didn't try one sooner." Razvan - 28 July 2021

Fuzzdog makes it better than the original
"Well, Fuzzdog makes it possible to build a better Expandora I guess! I built mine with 2x 3130EZ chips because I couldn't find the 308s easily and it sounds (probably) just as good. But the reason I went for Fuzzdog's board is because he adds the bass boost switch. I built mine to original spec but used a 470nF cap where Fuzzdog recommends it in place of a 100n, and used the 470nF cap on the switch. It definitely helps the pedal sound meatier than I remember from playing the original. All the gain settings are useful - I really like the lowest and second lowest settings. But the star is the "forbidden" mode - just be careful where you set gain before trying it! Hilariously saturated and gated - brilliant! My only quibble is that the drilling instructions aren't accurate. Twice I drilled boxes according to the instructions - I thought I had made a mistake first time. And both times the bass switch wouldn't fit. So I had to overdrill the hole to get the thing into the box. But other than that the board is excellent and everything worked first time as usual with Fuzzdog boards. Brilliant! Oh, and B100K works just fine for the tone pot if you don't have C100K." Jimmy R - 10 October 2019

Stuttering fuzz insanity - and a really nice overdrive / distortion
"As a huge ZZ Top fan, I've been after one of these for years. Originals are impossible to find and cost silly money, so when Fuzz Dog released this kit I grabbed on straight away. I'm glad I did. It's a simple build and the new (to me) direct-connect system saves a load of time and makes for a very tidy pedal on the inside. I went with the two-switch version, and added the optional caps for the bass boost with a jumper instead of the switch. The sound is actually a lot better than I expected - I was under the impression this pedal was all about the craziness of the 'forbidden' mode, but it's actually a really usable overdrive / distortion. The three 'unforbidden' switch settings give successive increases in dirt, which combined with the gain knob takes you from mild blues up to a point just short of Metal. It's quite a crunchy sound, more distortion than overdrive, and the pedal is quite bright and in-your-face. I like it, but it's not subtle. Then there's 'forbidden'. Gated, stuttering fuzz madness. Bizarrely, a Telecaster cuts through the mess best, giving a very convincing version of BFG's sound on Rhythmeen. Silly, and immense fun." John Roberts - 04 November 2015