BOME - A DIY Bass Oriented Multi Effect pedal

[SamIAm]

A placeholder for now, but more to come.

 

This diary will document my progress in creating a self build multi-effects pedal specifically aimed at bass.  It is driven by a combination of wanting a really powerful multi-fx that does not break the bank, leveraging the wide range of quality open source effects plugins available, being able to configure/control it in exactly the way I desire and keeping my "tech head geekette builder" fed.

 

Ideas currently being gathered in Dream bass multi f/x ... what would you want?

 

S'manth x

Edited December 25, 2022 by Smanth

[SamIAm]

So ... some initial thoughts, I'd love your feedback!

 

Brain: Rock Pi 4 SE ... because I have one.  Raspberry PI units are very difficult to source and the Rock is a powerful unit!  I plan (if possible!) to use the low power processors to power the UI and the high power ones for DSP. But I aim to ensure that BMFX will run on the variety of single board computers that are available.

 

Audio: hifiberry-dac-adc-pro  because I have one and it is an impressive bit of gear!

 

Operating System: Elk Audio was a strong contender with it's impressive low latency, but more than two years since the last update worries me!  I am likely to go for an Arch Linux system ... which is well maintained, can be configured in a small footprint fashion (I mean why would you want a BMFX to support printing!?) and is ARM compatible.  Regardless, my aim is a simple one click install, I do not want this to require any tech skills ... just the ability to plug in a bass and groove!!!

 

Audio S/W ALSA and JACK2 seem no brainers for me!

 

Plugin Host Carla strikes me as the most flexible choice to support most (if not all) plugin technologies.  Many are free, some are paid (And hopefully worth it!) and it appears to support "learning" plugins (Neural DSP ... you cost 10 times too much!!)

 

User interface hardware Multiple knobs and foot switches to allow for easy control when gigging!  Still pondering touchscreen (Which worries me from a durability perspective) but definitely a display that can be seen clearly during a gig! 

 

User Interface software from tablet/phone/laptop likely to be home grown, partly to allow for the capability to configure everything from dials/foot switches on the BMFX and also to  allow supporting web remote control from tablets/phones/laptops/etc.  This is perhaps the most challenging element.

 

I/O I'd love more feedback here please.  Mono/Stereo jacks? Midi (old skool, modern 3.5mm, BLE?) DI? F/X I/O for 4 cable setup?  Other things? More means a wee bit harder, but also more flexible!

 

Hopefully an early prototype in the not too distant future!

 

S'manth x

Edited October 19, 2022 by Smanth

[SamIAm]

Hmmm, seems Arch Linux is going to be a PITA to configure for the Rock.  I think I will go for one of the official Rock OS builds and tweak out the unneeded bits.  Likely to be easier/quicker and more reliable and it should allow me to prove the concept is sound, the tweaking can come in later!

 

S'manth xx

[SamIAm]

During my nursing degree I was blessed to have a 12 week placement in Sweden!

I loved it!

I realised a number of things during my time there ...

• It was a long drive! (I decided that having my car would make it easier to get to the two different hospitals I trained at)
• Sweden is a gorgeous country!
• Swedes are lovely people, it may take a while to get to know folks but it is worth it!
• Swedish is hard to learn (I mean, their word for nurse is sjuksköterska), it took me 6 weeks to be able to say it without people falling about in amusement! lol  "Hej, jag heter Samantha och är sjuksköterskastudent"
• I fell in love with intensive care there!

If my Swedish was good enough and the ... ahem ... travesty of Brexit had not happened, I would love to go there to live/work, the healthcare system is great, the country is beautiful, etc, etc

 

So what's your point S'manth!?

I have taken delight in naming various projects I've built using Swedish, for example, Trampa, Effektlada

 

The Bass Focussed Multi Effects Unit I am currently working on is now to be known as

Bas fx-enhet  (BFE)

 

S'manth x

Edited October 20, 2022 by Smanth

[SamIAm]

OK, Swedish is not the most .... trips off the tongue friendly language ... and so I have reconsidered.

 

I now introduce Proteus.  It will not be a fast build, but I hope it will be worthwhile and may be of value to some of you lovely BCers!

 

S'manth x

Edited October 20, 2022 by Smanth

[itu]

8 hours ago, Smanth said:

I have taken delight in naming various projects I've built using Swedish, for example, Trampa, Effektlada

Efektlåda! Nå just!

 

Listen now sjukskötare, I was under impression, that the unit is Lada (Ru##ian L.A. D.A.), but it seems to be låda (a box). Well, Lada is also a box of a kind.

 

(Nå, I am nåt Swede. Althåugh I am writing this cåmment in Ståckhålm because åf wårk trip. Weather here is cåld.)

[JapanAxe]

I have built a few pedals (and indeed a few amps!) but it has never occurred to me to try a multi fx, other than perhaps housing the innards of 3 or 4 pedals in a single mahoosive enclosure. The whole digital thing is well outside my comfort zone as a builder. I don’t know any programming but I seem to recall there are some people here who do.

 

I currently own one (1) bass-specific pedal, which I use as a recording preamp or silent stage solution so I’m not at the front of the queue of people dreaming of bass multi fx. In the past I have used overdrive, phasing, and envelope filter on bass, but the one bass effect I miss is the PWM synth sound on my old Boss ME-8B - do you reckon you can replicate that with decent tracking?

[SamIAm]

23 minutes ago, JapanAxe said:

I have built a few pedals (and indeed a few amps!) but it has never occurred to me to try a multi fx, other than perhaps housing the innards of 3 or 4 pedals in a single mahoosive enclosure. The whole digital thing is well outside my comfort zone as a builder. I don’t know any programming but I seem to recall there are some people here who do.

 

I currently own one (1) bass-specific pedal, which I use as a recording preamp or silent stage solution so I’m not at the front of the queue of people dreaming of bass multi fx. In the past I have used overdrive, phasing, and envelope filter on bass, but the one bass effect I miss is the PWM synth sound on my old Boss ME-8B - do you reckon you can replicate that with decent tracking?

I cannot think of any technical reasons not to be able to do so!

 

As Proteus develops let's see if we can achieve the sound you desire!

 

S'manth x

[SamIAm]

I need your help!

 

F/X without any good input sounds are a bit ... useless!

 

My bass playing ability is perhaps 2/10

Over time it will improve but for now ...

 

I would really appreciate any recordings you can supply of "clean" bass grooves for me to pass thru the f/x chain and see how they sound.

 

Th higher quality the better (naturally!)

 

Download links or perhaps links on basscamp?

 

Many thanks in advance!

 

S'manth xx

[Geek99]

I’ve been to Sweden, we canoed on lakes and went to gronaland and saw the Vasa which was totally immersive 

makes the Mary rose look like a pile of matchsticks

[itu]

On 21/10/2022 at 01:33, Smanth said:

I would really appreciate any recordings you can supply of "clean" bass grooves for me to pass thru the f/x chain and see how they sound.

Local library, bass books with code to grooves, or with a CD?

[andruca]

Hi, just saw this thread. I've been forever wanting to make something like this (more like the Ouya of multiFX, with some open source scripting to make "models" a DSP would then execute). Please, count on me for anything, from those clean bass recordings (have many basses and can play whatever styles, fingers or pick, and can provide quality recordings no problem) to anything programming (I make a living out of PHP/Python mostly, but am fluent with many other stuff). Also have a Raspberry Pi400. Just not familiar at all with the dealings of DSP. OTOH I'm a great functional analyst/advisor when it comes to multiFX, I have huge experience with them (many brands and their different generations).

 

P/S: Proteus is an old synth/sampler model by E-mu, some trademarks might be involved there.

Edited November 4, 2022 by andruca

[Owen]

I saw this and thought of you. https://www.musicradar.com/news/rnbo-max-launch

[SamIAm]

Rather a long time since I've done any work on this (or indeed done much at all; serious bout of depression following the impact of the fire and some other life affecting stuff, but it's clearing).

 

I stumbled across another audio unit called Proteus so will be referring to this as BOME until a better moniker comes along.

 

I've done some playing over the past couple of weeks and I think I have closed out on the tech stack for the BOME prototype.

 

Hardware

Raspberry Pi 4b - I have one that I salvaged from the fire and whilst they are in short supply at present, this should hopefully change in the next few months.  It is a cheap unit and well documented; it also supports the software stack I have selected.

HiFiBerry DAC+ADC Pro - This is a good quality, reasonably priced, Pi add on board to allow stereo (or two mono) audio input and outputs (Again something I was able to salvage from the fire). It is supported by the software stack I intend to use.

Touch Sensitive Display - This will allow for configuring BOME without needing a computer to do so (Tho BOME will also be configurable using a web browser)

Rotary Encoder/Switches - Used to supplement the touch display when configuring BOME as well as tweaking pedal settings on the go.

Footswitches - To allow handsfree control of BOME whilst playing; select defined pedalboard layouts, activate/bypass 'pedals', load setting snapshots, activate tuner, etc

Expression Pedal In - Allow connection of a 1/4 Jack TRS expression pedal to control pedal effects.

Pi Pico - A low cost microcontroller that will be used to interface between the Pi and the various input controls; It will offload some of the load from the Pi as well as providing some capabilites the Pi does not have (such as ADC for the expression pedal)

USB Host Port - Allow the connection of a USB MIDI Device to control any plugins.

USB Device Port - Allow connection to a computer to allow BOME to act as an audio capture/playback device.

 

 

Software

Elk audio OS - This lies at the heart of BOME.  It is based on linux (so allowing the use of linux capabilities and development tools) with some added goodness:

• ElkOS has a realtime element that interfaces with the HiFiBerry Audio card that has an extremely low latency, this means that the likelihood of experiencing audio artifacts like jitter or dropout is significantly reduced
• Elk Sushi is basically a DAW and allows for the use of both LV2 and VST3 (linux based) plugins. Sushi hands over all responsibility for the user interface to BOME, allowing for both touch panel and remote web control.

BOME-APP - Bespoke code running on the Pi that ties everything together and provides the logic and user interface for BOME.

BOME-IO - Bespoke micro-controller code running on the Pico to make the various switches and controls available to BOME-APP.

 

With my 3D printer still being out of service (The fire melted most of the plastic elements and I've yet to replace them) I resorted to a heath robinson approach using cardboard and duct tape to construct a prototype enclosure.

 

Currently 250mm wide (constrained by the spacing required for the footswitches) 140mm deep (Driven by the 5 inch touch sensitive display) and 60mm high, not counting the knobs.  I may lose one of the footswitches to allow me to reduce the width to 195mm, but I'm going to run with this setup for the time being.

 

Thus far I have been able to assemble the Pi, HifiBerry and some audio in/out; install the Elk software; configure a pedalboard with both a MIDI synth VST3 plugin and a guitar f/x chain using LV2 plugins for a compressor, chorus and room reverb; with a bass guitar plugged in and a midi usb keyboard attached I've been able to play both synth and the bass, driving a bass combo cab ... and it sounds pretty good!  I've been able to use an app called Open Stage Controller  running on my laptop to send OSC commands (A bit like MIDI but much richer) to change pedal plugins settings over a WiFi to the BOME unit.

 

Next to start on the BOME-APP, to allow web based management of pedalboards (A set of effect plugins connected together), pedals (An individual plugin that provides a single pedal type of effect such as compression/overdrive/chorus/reverb/etc), connections between them (Virtual equivalent of patch cables).  In parallel to this I need to start looking at how to achieve as many of the same capabilities using the onboard display and controls, Elk does not provide any display libraries so I need to figure out how to incorporate them to drive the touch screen as well as accepting input from the rotary and foot controls.

 

S'manth x

 

Edited December 9, 2022 by Smanth

[PaulThePlug]

Wow...

Looks great... Just an observation...

Maybe go slightly wider to give a bit more case either side of the outside foot switches of half the width of the between footswitch? Maybe give a little better anchor to any pushing turning effect when using the outside switches wiv ya foot

 

The rest is way over my head...

[tauzero]

Hmmm. I have a Pi 4, HiFiBerry DAC + ADC Pro, 7" HDMI/USB touchscreen, assorted footswitches, might have some rotary encoders knocking about. Must have a play with Elk OS.

 

And it's good to see you back posting too.

Edited December 10, 2022 by tauzero
Trying to improve my social skills

[SamIAm]

32 minutes ago, tauzero said:

Hmmm. I have a Pi 4, HiFiBerry DAC + ADC Pro, 7" HDMI/USB touchscreen, assorted footswitches, might have some rotary encoders knocking about. Must have a play with Elk OS.

 

And it's good to see you back posting too.

Thanks @tauzero, it's nice to have something (hopefully) interesting to share.  Previously I had thought that Elk was dead, but whilst their forum is quiet, they had a large investment (apx 2.6 Million USD) back in May and seem to be dropping new code; a bit like Mod audio they have a mixed commercial/OSS licence model and seem to produce one hardware device, for jamming over the internet.

 

I'm in the process of trying to build their Pi image (It's yocto based and new to me) at which point I can try incorporating Qt into the image for the onboard UI.

 

Cool that you have the various bits of the hardware stack ... If you might be interested in trying out some of the stuff or even some joint development drop me a PM?

 

S'manth x

[SamIAm]

So, this is as much to document my progress for myself as to share news of what is going on.

 

To setup a Pi to run ElkOS one needs to flash an Elk Audio OS Image to an SD card and then start the Pi with it inserted.  Elk produce an image, however it is missing a few elements that I need (such as a graphics library to allow me to drive the BOME onboard TouchPanel) and also lags a bit behind some of their own development of some of the software components (For example their Sushi DAW).

 

As for many organisations that produce a linux build for devices like the Pi, Elk use a build environment called Yocto.  It is an amazing open source initiative that allows one to "Stand on the shoulders of giants" when producing customised linux configurations.  Elk publish the Yocto configuration they use (as well as the source code for their USP elements of ElkOS).  Yocto is mind twistingly powerful and presents a rather steep learning curve!

 

BUT

 

I have been able (tho it took quite a few false starts, loads of reading/head-scratching, installation and re-installation of stuff on my build server) to generate my own image to flash to an SD card ... and it actually works!  The initial build took hours and hours as it basically had to build an entire linux operating system from scratch; I can now start to tweak it to include the bits and bobs that I need for BOME and thankfully, the build time for these additions should be much shorter.

 

And during the wait for builds to complete I've been practicing my scales and arpegios 🤣

 

S'manth x
 

Edited December 12, 2022 by Smanth

[mario_buoninfante]

hey,

over the years I have been using this (https://blokas.io/pisound/) with their OS too, that out-of-the-box allows for remote controls too. worth checking it out, maybe even just for inspiration.

[SamIAm]

42 minutes ago, mario_buoninfante said:

hey,

over the years I have been using this (https://blokas.io/pisound/) with their OS too, that out-of-the-box allows for remote controls too. worth checking it out, maybe even just for inspiration.

Spot on, nice system. In my early days of playing with pi based multi f/x that was one I had a look at and play with it.  Its MODEP interface is a modified version of the open source Mod Devices ModUI. Rather nice (and also used in the PiStomp Core and Zynthian systems).  I ended up crafting my own configuration of a real time linux (Like patchbox OS) but using a more recent version of linux and using the actual Mod UI code, which brought some extra features (I think CV at the time) as MODEP was a few version behind ... this was the EffektLada unit and I actually gigged with it, but the lack of onboard controls (requiring me to always have a tablet with me) was clunky and made me dig a little deeper into incorporating them.

 

More recently I decided I wanted to build a system that could support VST as well as LV2 plugins (The Mod software only supports LV2) and was looking at a system called Carla ... but further research led me to the Elk OS.  Elk dove deep into the core of linux using a technology called Xenomai which allows for a dual kernel (heart) for linux and is able to achieve insanely low latency when handling audio, Elk claim as low as 2ms!! (Compared with RT Linux used in all the other systems I looked at which are pushed to achieve 15 ms latency) which means more processing is available with less lag/jitter ... it does require special drivers for the audio card, but Elk have produced these for the Hifiberry card.  There are a few other technical features Elk OS has (A redundant file partition to protect against corruption or power loss during updating, buffer sizes going down to 16 samples, ability to be run on other boards than the Pi) that are attractive to me.  Additionally, their software that hosts the plugins runs in a totally headless manner, forcing one (or from my perspective freeing one) to provide a complete UI ... I like the uniformity of UI that this will allow me.  And Elk have insanely detailed documentation! In the end it will take me a significantly greater effort to achieve what I could using the Mod based approach ... but in the end I think it will be more flexible, be exaclty what I want ... and I enjoy the tinkering

 

S'manth x

Edited December 12, 2022 by Smanth

[mario_buoninfante]

Cool.

Yeah, I'm familiar with these tools as I've been a Linux user for almost 10y now. I use it to make music professionally and use tools like Carla.
I'm aware of Elk too, defo a lot of potential there. Never used it myself though.

I did use Bela that, like Elk, offers a really low latency, but it's a bit of a different beast though.
Anyway, looking forward to seeing your multifx coming to life!

[SamIAm]

1 minute ago, mario_buoninfante said:

Cool.

Yeah, I'm familiar with these tools as I've been a Linux user for almost 10y now. I use it to make music professionally and use tools like Carla.
I'm aware of Elk too, defo a lot of potential there. Never used it myself though.

I did use Bela that, like Elk, offers a really low latency, but it's a bit of a different beast though.
Anyway, looking forward to seeing your multifx coming to life!

How cool!  I've played with music editing with DAW stuff, but it's really very basic stuff!  When I was looking around I saw the Bela, but as you say it seems to target a different set of usage ... but really interesting!  BOME is going to be a labour of love and likely take quite an age to mature, but it'll keep me out of trouble ... and as I'm stalled on my bass build (due to back trouble) it will be a good creative outlet.

 

S'manth x

[Mykesbass]

On 20/10/2022 at 23:33, Smanth said:

I need your help!

 

F/X without any good input sounds are a bit ... useless!

 

My bass playing ability is perhaps 2/10

Over time it will improve but for now ...

 

I would really appreciate any recordings you can supply of "clean" bass grooves for me to pass thru the f/x chain and see how they sound.

 

Th higher quality the better (naturally!)

 

Download links or perhaps links on basscamp?

 

Many thanks in advance!

 

S'manth xx

Hi S'manth,

Might be worth sticking a request up in the recording section - a lot of Basschatters do stick to certain sections and the right people may not see this request.

[SamIAm]

Not a lot of forward motion at present

My attempts to incorporate onboard display capabilities into the ElkOS have not been successful, I am going to have to wait until they release their next version of their OS (Which was due end of lat year) to try again.

In the meantime I have reverted to trying an installation of pi-stomp, but I was getting really disturbing audio artifacts (random popping as well and pops when activating/bypassing individual effect plugins). I then tried patchbox OS again, but I am still getting random pops (tho no bypassing artifacts).  Both are MOD open source software based (which only supports LV2 plugin) but now use a much more current version and work well if I can resolve the audio artifacts; they both run on the normal PiOS linux, so tho their latency will be higher than ElkOS, there will be no issues with onboard display capabilities; pi-stomp already has some tho they will need some tweaking to run on my BOME configuration.

 

As I run BOME off a high power USB battery bank, I do not think it is any mains based interference causing the artifacts.

I need to install some decent shielding (as the current housing is cardboard!) to reduce any EMI and see if that resolves the issue.

 

S'manth x

Edited January 16, 2023 by Smanth

[SamIAm]

After creating a shielded housing for the HiFiberry card (Which I located away from the Pi via some GPIO extension wires) I found a slight improvement, but was still not getting the audio quality I hoped for.

I looked around to see what alternative ADC/DAC cards exist for the PI ... not many!

And then I stumbled across a 'as new' MOD Dwarf for an irresistible price ... and took the easy way forward!  I collect it on Saturday  

 

It is possible that I might revisit BOME when/if a new version of ElkOS comes out, they use their own device driver for the HiFiberry running at a super low latency and I think this might address the noise artifacts I've been getting.

 

In the meantime however, I'll be looking at how to 'tune' the Dwarf to my liking by adding an external footswitch and expression unit (most likely self build like the Trampa unit I built last year) and might even dip into writing a plugin or two that are bass focussed.

 

S'manth x

Edited January 25, 2023 by Smanth