Noise issues

[StefanD]

Hi all! So I have a lot of noise coming out of my Dwarf on my favorite pedalboard, it’s a high frequency constant pitch noise which sometimes stutters a bit. Unfortunately I want to play with very low dynamics on a bass clarinet so I don’t consider the noise gates as an option, they cut out a lot of my soft playing.

This is my pedal: StefanNoise - MOD Audio
I have recorded the noise as well with as close to absolute silence in my room as possible, if you increase a bit the volume on your speakers you will hear it.

This lead me down a rabbit hole trying to figure out the cause. For testing I am using ATH-M30x headphones plugged directly into the Dwarf and I have plugged a SM57 as input through a Zoom MAA-1 Mic Amp. I set the Input Gain on the device to 9dB to reach a max yellow/orange color when I shout into the mic.

Ruling out the noise causes:
First that came up was noise from the power supply / network. I bought an Anker 25000mAh 165W powerbank and powered the Dwarf with that and a 12V USB PD Voltage Converter. Same noise, so this rules out the power supply / ground loops as a potential cause.

Next I tried unplugging the mic and the pedal still produces noise from an empty input

Next I tried to load up the default pedalboard, so just plain connecting the input to the output with a stereo gain. No noise! So the issue has to be the plugins which I’m using.
What is surprising to me is that the noise doesn’t really register on a level meter. I turned the mic amp all the way up on the empty pedalboard and it outputs around -70dBFS to -16dBFS and zero noise.

When I loaded my noisy pedalboard it showed same levels as the empty pedalboard at rest but full noise.

So it doesn’t seem to be a pure gain staging issue either, unless I am amplifying specific noise frequencies.

I tried something weirder, I unplugged all cables from the outputs and connected the input straight to the output and nothing else. Now I have some barely audible noise, muuuuuuch lower but not the silence I had in the empty pedalboard

So from this I have to conclude that the CPU usage is increasing my noise floor? Which then gets amplified by the plugins? The first jump in noise I notice if I connect from the compressor straight to the output. And the noise gets amplified by the rKr Reverb a lot more even when I turn it off. Just passing through it generates noise.
Unplugging all the outputs from the Looperlative LP3, Shiroverb, Timewarp and Reverse reduced the noise volume but the noise is still very audibly there.

Do you have any suggestions on what I can do to fix this? I tried adding a EQ right before the portal and doing a scan over different frequencies zeroing out their volume but it seems like it’s not a single frequency.

[StefanD]

As another test I loaded up the default: A Warrm Welcome - Shimmer Delay pedal and there is no noise there either. So it has to be related to the plugins I’m using or how I am connecting stuff? At least that rules out a broken device.

[StefanD]

Oh… most of the noise went away after I disconnected the empty input from the eq (I had my mic on input 2 but also had the empty input1 connected to the eq)… That was stupid. But still there is some noise left and it seems like the more cables I route to the output, the more noise I have. I assume all the cables going to the output are summing up their noises and I get more noise. Is there a better strategy than just having 5 gain controls going to one output?

For example this pedal has totally 0 noise

[StefanD]

This finally gave me 0 noise! Something is up with the portal. It seems to add noise which then gets amplified by the plugins

[Rom]

Hi,
Did you try to use the input processing ?
https://wiki.mod.audio/wiki/MOD_Dwarf_Device_Settings#Input_Processing

[StefanD]

As of my last post above I found out that the issue is the portal not the input, so I assume that adding a noise gate through input processing would not change that.

[Rom]

You may here the CPU working, no ? Isn’t the noise quieter when you try with the buffer at 256 samples ?

[Rom]

Ah… Okay

[StefanD]

Setting buffer size to 256 with the portal connected funnily enough makes the frequency of the noise go down but it’s still there (but less annoying than the high pitched noise).

Just adding the cable straight from the portal to the output makes the noise appear. If I remove it there is silence

[StefanD]

A bit more experimenting it seems that the actual noise added by the portal is small but mostly it gets amplified by the plugins and the summation of that noise from the parallel effects it goes through.
So it’s part issue with the portal plugin and part gain staging issue. I managed to get it to a low enough level that you need to stick your head to the speaker to hear the noise. It’s more audible with headphones but it will work for my purposes.