Pictures and Descriptions of musical instruments, effects processors and sundry gadgets that we've built, midified or modified. May contain circuit diagrams, if we haven't thrown them away...
Some of my Axoloti patches these days require more than the three footswitches I've got with my original pedalboard controller design. I allowed for future expansion of the controller and the signals required for additional footswitches are available on a free RJ45 (Ethernet) connector. There's no room on the pedalboard but I can have a standalone switch box plugged into the controller and put it just in front of the existing footswitches. It means a bit of extra setup at gigs and rehearsals but that's acceptable.
The spare connector has 0V, 3.3V and six I/O pins. I can use three of those directly for the footswitches - they just need to connect the input to 0V when pressed (the Arduino pins have internal pullups). The remaining three pins can be used to drive LEDs, although not directly. To keep the Arduino code the same for the new LEDs and to avoid overloading the outputs we need some transistors to turn the LEDs on, with the current coming from the 3.3V supply. So an external PCB is needed and this also is a good way to isolate the controller from any mechanical stress of having a standalone footswitch box connected and disconnected regularly.
The PCB schematic:
It's not ideal that the only available power rail is the Arduino's 3.3V. The risk is that the footswitches and/or the associated LEDs induce glitches or noise on it, risking causing the Arduino to misbehave. The main footswitch uses the raw 9V for that reason. So, apart from the transistors and their base and collector resistors, I added some decoupling capacitors and a series 10 Ohm resistor to try to protect the 3.3V supply. The resistor values were chosen after experimentation. 2k2 is quite high for LEDs but I don't like them to be too bright so they'll be fine.
The layout:
What it should look like:
There will be a short Ethernet cable from the controller to the PCB and the new footswitch box will be plugged into the other RJ45.
Nine days after ordering them from JLCPCB for the incredible price of less than £4 including shipping, the PCBs arrived:
I fitted the surface mount components first. Easier with a microscope:
Then the RJ45s:
Before I could test it I updated the Arduino firmware to support the additional footswitches and LEDs, and also added them to the iPad layout in MIDI Designer.
I had a footswitch test board kept from the original controller development. As the connections for the new box are the same as on the original, I was able to use it to prove that all the switches and LEDs worked as expected before building the new box.
The PCB needs to be mounted in the small free area on the pedalboard. I decided to raise it up a bit so designed and 3D printed some supports:
The end result:
The new footswitch box is just some aluminium channel. I couldn't find a standard enclosure with the right dimensions. I drilled some holes:
Then added the switches and LEDs and a suitable length of Ethernet cable:
Initially it won't have sides or a bottom. I may add them in future for extra protection. As it is the wiring is securely tie-wrapped to some chunky copper wire I used for the 0V connections. It shouldn't move in use or in transit.
Testing was easy - I just repeated what I'd done earlier with the test board. Happily the wiring was good and everything worked.
It's intended to sit just in front of the pedalboard, offset from the other footswitches to make it less likely that I'll hit the wrong one. I'll have to see whether this is the best arrangement long-term.
Occasionally, people ask about my pedalboard so I thought I'd document it here. It's changed a lot over the years but this is what it looks like in 2024:
Signal Path
The pedals are divided into two groups. The 'Foogers are in one with all the rest in the other. The switch box can be used to select which comes first in the signal chain. It's also a good place to have the main input and output connections.
Control Signals
Controller
A home-made Arduino-based controller with control voltage outputs (CVs), analogue inputs, MIDI in/out, switch outputs and support for three assignable footswitches. The firmware allows the CV outputs to be driven by fixed levels, oscillators, noise sources and more. The controller can store patches with settings for all of these features and the patch is changed via buttons on the top. It is configured via the MIDI Designer app running on an iPad connected over Bluetooth [Low Energy].
The hardware development is described here, the firmware here.
Pitch Fork
I modded an EHX Pitch Fork to allow the controller to save its settings and to give CV control of the blend. That development is described here.
Dual Freeze
The dual Freeze box contains two EHX Freeze pedals that can be turned on and off by the controller. It also has send and return so that other pedals can manipulate a frozen sound, which can then be frozen again. I haven't used this much but it can create some interesting effects that I'd still like to explore.
Compressor
This is just a Build Your Own Clone kit that I couldn't be bothered to label.
Expression and Volume
These are unmodified Boss pedals that are a good size to fit on the board, but I don't like them much - most of the action happens in the last third of the pedal's travel. I'd prefer something more linear across the whole range.
Axoloti
This is an Axoloti Core board built into a box, and it really deserves a whole post on its own. It's a DSP device designed for audio processing, with numerous 'objects' being provided by the original designer and the community that existed around it, but also allowing for new ones to be developed. The board is no longer made although a new alternative has been developed (Ksoloti) and there's a description of Axoloti included in its documentation. Axoloti patches are stored on an SD card and can be selected by the controller via MIDI. This is the patch for the Zaardvark tune Moagulum:
This patch has chorus, reverb and some custom loopers. Others have distortions, phasers, delays, sample playback and a load more.
Geiger Counter
This is a distortion/fuzz/noise pedal that makes some really horrible sounds (which is good). It's in the Axoloti's send/return loop to provide wet/dry control which allows me to tame it slightly.
The Future
The board does most things I need it to but there are a few things I'd like to improve:
I'd like more footswitch inputs to the controller to allow more complex Axoloti patches.
The board is very noisy, probably due to me not paying enough attention to ground loops etc. but also because the controller is an Arduino in a plastic box.
It all works well live but having to use an iPad to configure the controller and a laptop to program the Axoloti means it's hard to make adjustments in rehearsal.
Andy has a Line6 Bass Pod and needs to control it with his feet. He needs to be able to turn on and off three different effects. The official Line6 footswitch is no longer available but the features can be controlled via MIDI, so we need a box with footswitches that send the appropriate MIDI Control Change messages.
I started with a 3D model to help with visualising where the switches should be. Having them in-line across the front of the box increases the risk of hitting switches 1 or 3 when aiming for 2, hence the offset approach.
In previous projects I used some kind of Arduino, but I fancied trying CircuitPython for this project. This has the advantage of the code being stored on the module, allowing anyone to modify it without the faff of toolchains and the relative complexity of C++.
Some requirements to start with:
It needs to be powered from Andy's existing 9V daisy chain.
The MIDI cable should be captive so the cable can't become separated from the footswitch, and to simplify setup.
Each footswitch has a corresponding LED.
It must be mechanically robust.
I happened to have a Seeed Studio XIAO RP2040, so the design is based on that. I considered hacking it together on Veroboard, but the ridiculously low cost of PCBs from JLC PCB made a custom PCB too tempting. It also makes it easy to allow for five switches and LEDs in case that's needed in a future project.
The schematic:
The XIAO can only handle 5V. The current requirement is only tens of milliamps so an old-fashioned voltage regulator is fine. Here's the final layout:
At least one Zaardvark tune requires Andy to operate his fuzz pedal at more or less the same time as playing the bass pedals. The positioning of the two - about a metre apart - makes this difficult to pull off. What is needed is a remote footswitch for the fuzz pedal that can be placed very close to the bass pedals, making it much easier.
The pedal is a Boss FZ-5 and, like most Boss pedals, uses a momentary footswitch. This makes it simple to bring out the switch's contacts to a socket, allowing a remote footswitch to be connected in parallel. But it also seems useful to have an LED on the remote that confirms the pedal's on/off state. This is more difficult to achieve as you can't just connect an external LED in parallel with the internal one. A buffer circuit is needed:
LED_IN connects to the FZ-5's LED anode. When it is off, no current flows into the base of Q1, so R4 pulls the base of the U$1 to 9V, turning it off, so no current is supplied to the external led via LED_OUT. When the internal LED is on, Q1 and U$1 are turned on, supplying current to the external LED via R3.
This circuit could have been fitted on Veroboard quite easily, but I wanted to get more experience with assembling surface mounted components, and fancied the challenge of making the board as small as possible. The final layout is 17.5mm x 3.5mm:
It's double-sided and will fit inside the pedal easily, enclosed in heatshrink.
Assembly:
Connecting to the 9V supply at the power socket:
Connecting it up inside:
The remote footswitch is connected through a stereo mini-jack socket:
We recorded it with Matt Musial at The Burrow studio in Bournemouth. It was mastered by our long-time friend and hero, Gary Hudspith.
Here are some facts about the tracks:
Avalon Broke My Back (And I Wept)
Time signature: 9/8
Adorned with horns arranged by Dave and Andy, and played by ridiculously excellent jazzcats Ed Johnston (ts), Louisa Revolta (as) and James Lush (t), this tune made us seriously consider writing horn parts for the other tracks on the record. The outro features The Burrow's thumb piano and some eye-rollingly atonal frozen guitar chords courtesy of this. The rhythm section is augmented by overdubs of the Zaardware ZB6 and a keyboard we know as "The Brown", which is a Siel Cruise synth manufactured in Italy the early '80s. This instrument is an odd combination of a very limited monosynth and a very limited stringmachine-type polysynth. It's neither very good or desirable, but it does have its own distinctive set of sounds that we made extensive use of. I think it must have the highest switches-to-usable-sounds ratio in the history of synthesizers, but we do love it.
Mark and The Brown
Kot
Time signatures: 12/8, 9/8, 6/4, 6/8
This was developed from a very old demo which featured the sound of a close-miked bicycle wheel being run through all the effects pedals I owned (a sound that didn’t make it to the final version, sadly).
When Zaardvark first started, we had five members (the three of us, plus keyboardist Kerrie and drummer Rich), and we were called Spacecunt. We never did any gigs with that name, but we did start work on several tunes that would survive the great downsizing that saw us become Zaardvark. This video is a run through an embryonic Kot in the echoey old hall we rehearsed in. The arrangement of the recorded version has undergone extensive change, with several new sections, all derived rhythmically somehow from the 3 times table.
The outro fuzz bass (a borrowed Squier Jaguar short-scale) played by Dave standing on an amp, making rock shapes. The track fades out via an automated high-pass filter.
A radical edit of the original 12" dance mix. Features two drum kits - a normal sized one, with each drum recorded individually to a click (like Heart of Glass), plus a tiny one played conventionally - and three basses (Jazz bass, synth bass and Zaardware ZB6). The melody was written using an audio variation of William S Burroughs’ cut-ups method, and at an early stage there was going to be guttural pseudo-singing. The dub guitar noises were made with the precision multi-fx.
Dave (L) and Matt (R) measuring for overhead mic placement.
Square Leg
Time signature: 4/4 (with the odd bar of 3)
A legacy of our Spacecunt phase, this combines a very old tune of Dave's (jammed here at great length) with a much better tune written by our friend and former keyboardist Kerrie, around which Mark devised the harmony / delay guitar line and Andy came up with the bass solo at the end. The modal noodling was done with Thumbjam, an app we downloaded to amuse the small children in our lives. The guitar 'solo' at 3:00 is mostly Moogerfooger Ring Mod on one of its gnarlier settings. In the first half Andy plays samples of Mark (more frozen guitar chords) with his feet.
Malignant Imperialism
Time signatures: 5/8, 6/8, 10/4
This probably should have had horns, but has skronky guitar, stylophone ensemble and The Brown instead. The initial groove/riff was the result of a challenge Andy set himself to see if he could come up with something that would confuse his band mates but still sound good, and once we'd eventually gotten our heads around it, the tune was developed into our proper first three-way collaboration. The repeated vocal sample is a choir of Andys (played on the organ pedals), the breakdown has a chord sung by a small choir of Daves, and the end section has the three of us singing joined by Catherine and Tiff, who could reach the notes we couldn’t. This is another tune where Andy triggers samples of sounds pre-recorded by Mark. Old footage of early development efforts can be "enjoyed" here.
Andy cheating by using his hands to play the organ pedals.
Psychic Roundabout
Time signature: 3/8
This is electronically varisped so that it very gradually gets higher and faster from start to finish. The ascending guitar line 30s in is a Moogerfooger FreqBox set to track the guitar note, but with a pleasing level of incompetence.
Dave overdubbing with Matt's Jazzuar.
Elfmeter
Time signature: 11/8
Andy plays some lovely Hohner Electra Piano on this. When we perform this live Mark uses a 17-second delay to play the guitar part in canon with himself. The guitar 'birds' at 3:08 were created by driving a Moogerfooger Lowpass Filter pedal's frequency and resonance controls from noise sources built into the Pedalboard Controller.
This Steinberger baritone didn't work out and went back to the shop.
Planet Of The Plastic Miners
Time signature: 4/4
One day our descendants will be employed to dig through our rubbish to recover plastic we threw away when it seemed the oil would never run out. Again, this really should have had horns on the big unison riff. All three of us are playing guitar on this one. The guitar sound at 2:54 is a combination of the LPF and RingMod 'foogers, with the LPF's envelope output driving the ring mod's frequency control input. Then from 3:01 an expression pedal is used to ramp up the wet/dry blend of the ring mod to increase the unpleasantness. Dave recorded some rhythmic mining noises for this, but they sounded a bit too Seven Dwarvesy, so they weren’t used.
This tune was the only one we recorded twice - our first attempt wasn't up to scratch, so we started again. The new version fixed the issues we had with the first one, but the original had noises in the introduction that we really liked, so producer Matt got out the digital razorblade and splicing tape and made the old intro fit.
By the final drum session, we had a much bigger kit.
Hammo
Time signatures: 9/4, 4/4, 5/4
Having evolved from a jam between Dave and Andy when Mark was ill and unable to make rehearsal, this came out as a sort of Turkish reggaeton. Features flourishes from a Yamaha FS1R synth, along with synth guitar, synth bass and synth snare drum. And a mellotron brass sample played on the organ pedals. Our tunes have no singing, so we don’t call the sections things like “verse” or “chorus”. Instead, they have names like "The Scrunges", “Slidy fantasia”, "WWJMD?", and in this case “Gary Numan”,“Barry Puman” and "Slack Puman". The melody at 0:50 is a Pigtronix Mothership guitar synth sounding much cleaner and more controlled than it is in real life. It's a twitchy beast.
Mark prepares to double a guitar part with The Burrow's P-bass.
Transmission de Valerie
Time signatures: 7/4, 4/4
Comme la musique d'un Neo-noir drama. Banjo et mandoline, FS1-R et multi-fx de haute precision. En anglais:
the sustained guitar chords were produced by a combination of EHX Freeze pedal and EHX Pitch Fork, with the pitch control being modulated by a slow LFO from the Pedalboard Controller. The aim was to induce an uneasy, slightly queasy feeling in the listener. This is the one track where the ZB6 is used as a conventional bass - elsewhere (e.g. Avalon and Volveau) it's played in its higher registers, palm-muted, with a plectrum and with the pickups out-of-phase.
Learning the banjitar part for "Valerie"
We can't remember what this represents. It might be a guide to comp together takes of something.
Andy's Bass VI
Dave tracking vocals.
Some drums.
Can't remember which track we tried this on - it didn't make it to the final mix.
An Alden Quadrastar and various lesser instruments.
