My guitar pedal project


I’ve got my HiFIBerry DAC+ADC and I’ve been designing a new enclosure to make a guitar pedal. Here is my progress so far.

The Pi USB ports are pointing out the back. Power comes from a 9V pedal power supply and converted to 5V inside the box.

The left channel is used for the main guitar in and out. The right channel is used for the send/return jacks at the back of the enclosure. I’m hoping that the active buffer in the polytune will avoid any impedance issues with the direct guitar input.

There will be a stomp switch on the left for on/off, and one on the right for bypass. The pot in the middle modifies the output volume of the left channel.

I booted it for the first time yesterday and the output works fine, but the inputs are not showing up as alsa devices. My zynthian was running 4.14 kernel but I followed these HiFiBerry instructions to switch to their supported 4.18 kernel, but that didn’t seem to help

Is there anything I can do to get input working, or help out with the effort to add support for the HiFIBerry DAC+ADC?


Woaooo! It seems a MOD-Zynthian :grin: Congratulations!


I got input working, I just needed this in the webconf -> Hardware -> Audio -> Config:


The kernel7-hb.img image is the HiFiBerry custom kernel


I will include it ASAP! :wink:


For future guitar travellers, I set the input gain setting jumpers to 12 db gain. 32 db distorted for me.


Hello everybody,
im new to Zynthian…
RPi 3 with Standard Case. It works fine
But: I have buyed the HiFiBerry DAC+ ADC. No Problem with the DAC+ Driver. But i want to use the input and i followed the instructions by @steveb.
I have no luck: To much errors installing the new kernel.
Can somebody help me a little?

Best: Dirk

Zynthian_20190131_DAC ADC.txt (14.8 KB)


You should be running those commands as root, not as the pi user. You should be able to switch to root by running sudo su -


Hi steveb,
i am logged in as root.

btw: i hate Linux!

anyway: i try it.

root@zynthian:~# sudo su bash <(curl

WRONG! Im an idiot!

Im definitely root. What else i can do?



If you get an error message, please type it as it appears, “WRONG! Im an idiot!” is not a standard error and so isn’t much help to us.

btw: I hate Windows and MacOS, but if I need help from people who understand how to help me with them I tend not to go with it as a conversation opener. It’s an emotive subject though so I understand your hostility.

sudo su -

(you missed the critical hyphen at the end) is only needed to change to the root user, if you’re already root then you don’t need to run it.

Try instead, as root:

curl | bash

If it goes wrong, (it might) try to show the error as completely as you can.


If I remember correctly, I ended up running each line in update-kernel manually, omitting the sudo prefix in that script because I was already running as root.


What’s the extra knob on the zynth?

Burn the witch!


Hello again,
if i say: >I hate Linux < it means ironic… :grimacing:
I am not an Linux Guru. If errormessages comes up i am at the end of my knowledge.
Last night i try it by hand to install the hifiberry drivers as @steveb suggest it…

I think the driver is working…

… and there is an Audio capture device…

I GOT IT! :scream:

I edit the /home/pi/zynthian-webconf/lib/ file and insert all the stuff
for the dac+adc card. (9.9 KB)
It takes 2 hours before i understand that i must write “analogue” instead of “capture”…
But now it works and everything is fine for me.

Sometimes i hate Linux :grimacing:

Thanks for the comments. It helps.

Best: Dirk


Now that is interesting… :stuck_out_tongue_winking_eye:
Hand built snapshot or zynth default?

What was doing the rhythm?
and how much encoder tweaking made it in?


this is an fast’n’dirty “Remix” of the 808 Intro of Sexual Healing. Played from my phone directly
into the HiFiBerry input. Routed thru the MDA Delay with rough hand settings. :nerd_face:

Best: Dirk


That’s why I love Linux.
Windows crashes without notice :slight_smile:


Indeed it is…

I’m looking at the pedal rig (which is very nice) and I keep seeing more of the control footswitches and them laid out as a piano keyboard . . . :smiley:


Its a pot to set the output level going to the amp. There will be a foot switch to the left which will be the on/off for the pi, and a foot switch on the right to be a full bypass.


Thanks @steed
I committed the change.

This is the thread, I try to collect input like this, btw


Do you take care of the kernel7-hb.img?


The new SD image will include the new kernel supporting the Hifiberry DAC+ADC. I hope to release the new SD very soon!! Development is frozen now and the next SD image is my priority now… :wink: