x0x wrong envelope and filter resonance
Hi community :)
I did build up my x0x some yeras ago, like 4 to 5 I guess, and it did never work properly ( well it did work good enough to make music) but it always botheres me, to take a loot inside again.. so now here I am, open x0x with some questionmarks remaining.
This thread is for experienced and nerdish people only :) as I am an electric engineer, I am not looking for obvious error, although they happen a lot to me too, but lets pretend I did solder perfectly and every resistor and cap is in the right spot, sinc I do get acid sound out of my device.
There are 2 main points, firts the filter section, witht he "moog" diode filter, I think there is some amount of wrond resonance in mine, I will show you in a second.
The second thing is It might be that my output section is just too quiet, I have to pull the volumn always to full amount and have it boosted in order to fit into my mixes, the x0x itself is too quiet, It might have something to do with the out mixer, maye i put and preamp inside, or you guys can help me, maybe.
Both screens have the same setting: 5ms per box ( sorry no native speaker :) ) and 100mV the y axis
So As you might notice, the Vpeak peak voltages are way too high, in the adafruti manual its maybe a facotr 2 maximum, and I have a factor of maybe 10
I would say it is a resonance peaking of the filter, but I got no clue where this is coming from, I would assume my whole x0x is working fine, but something, little thing inside the ladder maybe got wrong so there is the overschhot.
Also when the peak peak feedback voltage gets higher than around 2V the volumn increased suddendly, as my best guess would be one of the transistors, that are there for the emitter long pair current of the last filter transistor pair, are saturated then, and are fully conducting, whicch causes this.
Any help maybe someone more expirienced than I am know which resistor and or cap and or transisstor is to be replaced :) As if it were that simpel :)
Well thanks anyway for reading, goodnight.