My guitar pedal project


#1

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?


#2

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


#3

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

dtoverlay=hifiberry-dacplusadc
kernel=kernel7-hb.img

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


#4

I will include it ASAP! :wink:


#5

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