Performance case 104 7u | bleeding and noise

hi there,

anyone here experienced bleeding or the like on a performance case?

i just started a new case from scratch with only a hand full of modules and the filter-8 seems to be affected be contour-1 (bleeding) and the quad vca (noise) without being connected to filter-8.
of course i tried different configurations in my case (and on the busboard) with filter-8 and contour both on different rows etc. but to no avail.
anything that i could do wrong when connecting modules?
is there a recommended order? should i start on a specific side/row … same goes for the pin connections on the bus board.

thanks for your help.

AFAIK connections on any header shouldn’t make any difference to noise, however, physical placement of some modules overtop the internal power supply board could possibly cause extra noise. Obviously be sure to mind the cable orientation on the module/powered busboard when plugging in.

Without knowing how you are patching your modules up, I couldn’t speak to why/where you are experiencing bleed/noise - I also don’t own any of these modules, however I have heard the Joranalogue stuff is supposed to be high quality, so wouldn’t expect any erroneous noise (however some modules are quirky/more noisy dependent on several factors).

From what you have stated - the Contour-1 is always sending/bleeding CV out into the Filter-8 somehow? What are you using the Contour-1 module for exactly? (Slew limiter or Function Generator?) Assumedly the Filter-8 audio output is then ran into the Quad VCA audio input, and when doing this you are experiencing noise from Filter-8? - does the noise present itself when hooking up either Filter-8 or the Quad VCA unpatched direct to the audio output/interface?

thanks for your help!

sure, i should have mentioned that i use the contour-1 and the filter-8 both as vco´s.
that means that the filter-8 is running with resonance at maximum. when i dont selfoscilate the filter-8 but use it as a filter, the noise gts lower in level… but the bleeding remains.
when i slow down the contour-1 rate from audio to lfo rate than, instead of a tone, clicks/crackles are noticeable on the filter-8 output (used as a vco).

i also forgot to say, that i patched from filter-8 straight into my 1u headphone out. i also tried to patch into quad vca before going into headphone out but to no avail.

from further testing i have the feeling that
a) fiter-8 is the only module that is sensitive for the bleeding of the contour-1.
b) i also seems that the noise on the filter-8 output (in vco mode) is affected by more modules that the contour-1. when i disconnect other modules form the board -having only filter-8 pathhed to headphone out- it seems that the sound gets cleaner -with less noise. the more modules i disconnect… hmmm.

thanks again for your feedback and sorry for my incomplete first post…

Are you using balanced cables for your output? Noise issues can be tough to isolate and diagnose, but being systematic (like you have been) is the best way to sort them out.

Many analog filter designs can have high gain stages as part of their topology. These are prone to picking up and amplifying any background noise in a system, particularly HF bleed from digital modules.

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hey guys, thanks for your feedback. i started a thread at muffs:
https://www.muffwiggler.com/forum/viewtopic.php?p=3164080#3164080

btw. i use sennheiser hd-25 headphones in the 1u-headphone jack.