Noise issues

Using MOD devices
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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.

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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

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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.

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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.

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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

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

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

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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.

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

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Ah… Okay

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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).

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

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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.

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Yes, that certainly contributed to the issue.

That’s 100% correct. That’s what I noticed immediately by looking at your pedalboard. You are multiplying the output of some plugins (especially dynamic and simulators, which always add gain) a lot of times by connecting so many cables from the same source to different places and then summing all together at the end with no selector or any gain compensation.
As far as I remember, the TAL Reverb is actually quite heavy on gain and miss matching with other plugins.

The portal is not intended to connect directly to the output, as that would essentially eliminate the benefits of utilizing different CPU cores for processing various plugin chains.

Exactly. I think that’s your main issue.

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Thanks so much for the confirmation! My knowledge of pedals is pretty much zero since I play acoustic instruments so it also took me a while to figure out that when I disable a pedal it obviously passes through the dry signal and doesn’t kill that path, thus summing up the noise. I managed to fix this now by adding a mixer at the end which mutes the output of each effect, although it makes for a bit uglier UI on my pedal (since I have mute foot switches instead of effect-on switches but I’ll get used to it).

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Another method I recommend testing for all “time plugins” is to apply sends, just like in a mixing console.

This can be combined with the possibility of re-injecting the effect into another plugin. Here’s an example:

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how about ToggleSwitch plugin(s) between the Portal and the effects plugins? …each output feeds an effect, they show as ON/OFF, and you can choose latching or momentary (in case that’s ever useful for you). essentially, we just leave the effects running and choose whether or not to feed them! (they’ll be totally silent when they have no incoming signal)

…or, if the MOD switch plugins cause clicks on switching for you, you could use some of @zwabo’s Toggle_2IN plugins, which have smoothed audio switching. (just leave one incoming leg unconnected, and use one before each effect)

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Wow! Both of these suggestions are super helpful for my pedal. Thanks so much!

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Another option could be using macro controls via CV. Then you would push a button and simultaneously turn on/off the plugin and unmute/mute their line on the mixer. Eventually, it’s a bit more elegant in CPU usage.
If you are up to try out stuff, I would also suggest taking a look at the Audio Router from @steve. That may also solve your issue.

EDIT: the macro idea also applies to @plutek suggestion

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