Filter Cuttoff @20Hz lets audio through

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Filter Cuttoff @20Hz lets audio through

Post by Noris » Fri Mar 08, 2019 10:20 am

Hey Guys,
I bought a Sub37 a few weeks ago from a friend. The last weeks i had decent fun.
The first time the problem occured yesterday. No matter which preset i load, while tweeking the cutoff filter to its lowest, there is always some sort of signal/sound going through. Normally the cutoff filter should mute the signalchain completely, right?
I remember that it worked perfect a few weeks ago. So maybe its just a wrong setting i did without being aware of?

The knob still delivers some midi signals and you can hear that something is going on. The sound gets edited a little bit, but just a little bit and very slooow.
That means its still working in a kind of way... :?:
if that helps...

Thanks in advance, guys!

Best regards,

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Re: Filter Cuttoff @20Hz lets audio through

Post by till » Sun Mar 10, 2019 11:06 am

Every filter has a rolling-off slope. And this is measured in dB per octave. The Moog filters are mostly 24 dB/oct. So a signal one octave above 20 Hz = 40 Hz is about -24 dB. You can hear the oscillator most likely, if they produce some content in this frequency. And it is another octave higher at 80 Hz -48 dB. Which is hear also. And at 160 Hz it is -72 dB. This is really low in volume, but might be heard on a loud monitor setting.
And are you sure there is no keytracking also opening the filter a bit? Or the envelopes modulation the cutoff too?
keep on turning these Moog knobs

Prodigy * minimoog '79 * Voyager * MF102 * MF103 * MF104z * MP201 * Taurus 3 * Minitaur * Sub Phatty * MF105 * Minimoog 2017+ MUSE * One 16

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Re: Filter Cuttoff @20Hz lets audio through

Post by Noris » Tue Mar 12, 2019 2:22 pm

Hey Till,
first of all thanks for your help. I really appreciate it.
Its not like you gonna hear some endfrequency sound. Its more like the filter isnt doing his job. i turned the oscialltors off already...
I think im gonna make a video. That will explain the problem in a better way. :(

As im a "newbie" to keytracking it sounds kind of what the filter is doing. it just adds some frequencies either way i turn it - but just a little. So you can say it always stays open.
At least i could try to disable it?
The only thing that confuses me, is that i resettet the Global- and MIDIsettings already 2 times.

With the Envelope Modulation you mean the Knob EG Amount, right? I already tried by turning it down or leaving it on "0".

Thanks again and a good week!

PS: Saw you are from Germany as well. Maybe communication in german would be a bit easier

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