Jan M

I started to run my first test of running RNBO on a Pi 4. First results are really promising. And I feel close to be able o build my dream rig :) 

I noticed though a clearly audible noise that sounds like processor noise/something spilling over the board electronics.

I used and external USB audio interface for he tests that I had at hand (Zoom U24) and the Pi was powered by the official RasPi power supply. The noise persists even when not connected to ethernet.

Has anyone experiences or tips how to best eliminate or reduce those interference?

I started to run my first test of running RNBO on a Pi 4. First results are really promising. And I feel close to be able o build my dream rig :) 

I noticed though a clearly audible noise that sounds like processor noise/something spilling over the board electronics. 


I used and external USB audio interface for he tests that I had at hand (Zoom U24) and the Pi was powered by the official RasPi power supply. The noise persists even when not connected to ethernet.

Has anyone experiences or tips how to best eliminate or reduce those interference? 

I started to run my first test of running RNBO on a Pi 4. First results are really promising. 

rnbo-on-raspi-looking-for-audio-interface-advice

@Jan, I am also interested in using RBNO with Rasp. Still waiting for a Rasp 4 because of the shortage. In between I bought a "HiFi Berry DAC+ ADCPro" to use it with the hopefully coming soon Rasp.

@Jan, noise sounds like typical ground loop, might be via the USB audio interface.

(unfortunately, USB can be a prone to this, though often its fine)

Ive just setup RNBO on rPI3b with pisound, seems to work nicely.

blokas pisound is a good solution, since you get not only audio io, but also midi, which is pretty handy in this scenario , where I want to create standalone instruments/fx. 

@Jan, noise sounds like typical ground loop,  might be via the USB audio interface.
(unfortunately, USB can be a prone to this, though often its fine)

Ive just setup RNBO on rPI3b with pisound, seems to work nicely.
blokas pisound is a good solution, since you get not only audio io, but also midi, which is pretty handy in this scenario , where I want to create standalone instruments/fx. 



it didn't really sounded like a ground loop as the audible noise was obviously related to processor activity. So my guess was more that the clock pulses of the pi bleed through to other parts of the circuit...

But yes the audio interface I used isn't the best, just a spare one that I had lying around.

I would be very interested in your experiences with the PiSound as this was the interface I had in mind for the final setup. do you think it would be good enough also for a studio/recording setup?


it didn't really sounded like a ground loop as the audible noise was obviously related to processor activity. So my guess was more that the clock pulses of the pi bleed through to other parts of the circuit...

But yes the audio interface I used isn't the best, just a spare one that I had lying around.
I would be very interested in your experiences with the PiSound as this was the interface I had in mind for the final setup.  do you think it would be good enough also for a studio/recording setup?

I did a little more testing, and it seems to be that temperature is a factor. If I add a DI Box with ground lift the background noise is negligible - at least for live/gig situations. 

But it starts creeping in again as soon as the Pi runs hot (which is unfortunately easily the case with the Pi4).

so adding some active cooling seems to be work in my case.

I did a little more testing, and it seems to be that temperature is a factor. If I add a DI Box with ground lift the background noise is negligible - at least for live/gig situations. 
But it starts creeping in again as soon as the Pi runs hot (which is unfortunately easily the case with the Pi4).
so adding some active cooling seems to be work in my case.

ground loops often do sound like processor activity... basically its switching noise. your ground lift basically shows this is the case.

I'm surprised cooling has much effect on it, as usually its more cpu speed processing related, due to how much power its pulling (and the power usage on the rPI4 makes this more common that older rPIs)

but I dont know all the electrical enginneering behind this, rather more usage experience of various SBCs.

Ive not noticed any noise with the PiSound... they have the specs on their websites, 

note: I use a rPI3b with the 1.0 PiSound, as Ive had it for a while, 

so probably a good idea to check for experiences with rPI4 and the newer 1.1 (?) pisound.

But its a quality product as far as Im concerned, and lots use it.

worth a shot, considering its a reasonable price.

I think the only 'drawback' is its only 2 ch in/out... which is pretty common for 'pi hats' , but may not be enough for some users needs

ground loops often do sound like processor activity... basically its  switching noise. your ground lift basically shows this is the case.

I'm surprised cooling has much effect on it, as usually its more cpu speed processing related, due to how much power its pulling (and the power usage on the rPI4 makes this more common that older rPIs)
but I dont know all the electrical enginneering behind this, rather more usage experience of various SBCs.

Ive not noticed any noise with the PiSound... they have the specs on their websites, 
note: I use a rPI3b with the 1.0 PiSound, as Ive had it for a while, 
so probably a good idea to check for experiences with rPI4 and the newer 1.1 (?) pisound.
But its a quality product as far as Im concerned, and lots use it.

I'm also using RNBO on a rPI3b with pisound. Unfortunately, everything sounds heavily bitcrushed once I get it on the device and connect it to my synth and mixer

Hmm, it seems like it's mostly the high sensitivity of the pisound mixed with the weird sounding gain control which seems far away from being a 

I really wanna like the pisound. It's lying around for years. I hope I can make this work smoothly…

Hmm, it seems like it's mostly the high sensitivity of the pisound mixed with the weird sounding gain control which seems far away from being a clean signal amplification

RNBO on RasPi - looking for audio interface advice