# Troubleshooting a performance filter **URL:** \ **Category:** KOSMO MODULES\ **Created:** [May 25, 2020, 9:08pm UTC](https://lookmumnocomputer.discourse.group/t/troubleshooting-a-performance-filter/1015 "2020-05-25T21:08:31Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![fluxpavilion](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/fluxpavilion/32/2475_2.png) [@fluxpavilion](https://lookmumnocomputer.discourse.group/u/fluxpavilion)\ **Post date:** [May 25, 2020, 9:08pm UTC](https://lookmumnocomputer.discourse.group/t/troubleshooting-a-performance-filter/1015/1 "2020-05-25T21:08:31Z")
hello my friends! here we are again, ready for another lesson in whats gone wrong (for me anyway) so i got it all built up (used a B10k pot instead of 4K7 but just for testing while i wait for the right one to come) i turn it on and nothing! not sure if the LED’s are suppose to come on power? but i tried running something through it and got nothing. firts thing i might have done wrong is wired the box jacks wrong, anyone know an easy way of telling which pegs to use for the hot and the ground? ive tested power to the chips and im getting both +12V and -12V to both. Im not sure which pins are the right ones, but checked for continuity and then checked the voltages and all seemed fine so here i am stuck again, not entirely sure what to check! ---
**Author:** ![fredrik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/fredrik/32/682_2.png) [@fredrik](https://lookmumnocomputer.discourse.group/u/fredrik)\ **Post date:** [May 25, 2020, 9:19pm UTC](https://lookmumnocomputer.discourse.group/t/troubleshooting-a-performance-filter/1015/2 "2020-05-25T21:19:21Z")
The LEDs are part of the feedback path, so they only light up when you have enough resonance. B10k instead of 4k7 is perfectly fine (see [here](https://lookmumnocomputer.discourse.group/t/1113-performance-filter/14/50) and there’s also a note on [Sam’s page](https://www.lookmumnocomputer.com/performance-filter) if you don’t trust a random dude on the Internet 😀). To check the box jacks, plug in a cable and use your multimeter to check connectivity between the plug at the other end, and the jack pins. You may find more useful tips in this thread: > [@1113 Performance Filter](https://lookmumnocomputer.discourse.group/t/1113-performance-filter/14): > > All Chats about this filter. maybe a mouser cart. or places people have found stuff for it. chat about it here! Im updating the filter panel relatively soon it was the first module I put out, for instance the mounting holes were made for wood screws only! instead of for both rails and wood rails like the others, however like me I can imagine most people building this are going down the wooden rails route!!! its the best! ---
**Author:** ![analogoutput](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/analogoutput/32/29663_2.png) [@analogoutput](https://lookmumnocomputer.discourse.group/u/analogoutput)\ **Post date:** [May 25, 2020, 9:24pm UTC](https://lookmumnocomputer.discourse.group/t/troubleshooting-a-performance-filter/1015/3 "2020-05-25T21:24:21Z")
Consult datasheets for the power pins on the chips. [TL074](http://www.ti.com/lit/ds/slos080n/slos080n.pdf?ts=1590441574568) (page 6), [LM13700](https://www.ti.com/lit/ds/symlink/lm13700.pdf?ts=1590441649179v) (page 1). Check the power header ( **before** powering it up again!): [https://www.youtube.com/watch?v=qS0SoIiiQCo](https://www.youtube.com/watch?v=qS0SoIiiQCo) Power header pins (the one on the right): ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/b/b711d13d66122622ca8001996d8332f44f280784.png) Usually the cable has a red stripe on the -12V side. ---
**Author:** ![Jos](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/jos/32/151_2.png) [@Jos](https://lookmumnocomputer.discourse.group/u/Jos)\ **Post date:** [May 25, 2020, 9:28pm UTC](https://lookmumnocomputer.discourse.group/t/troubleshooting-a-performance-filter/1015/4 "2020-05-25T21:28:36Z")
Maybe this is already known/clear, but when checking continuity it is best to switch off the power supply to the board or to disconnect the power. ---
**Author:** ![d42kn355](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/d42kn355/32/273_2.png) [@d42kn355](https://lookmumnocomputer.discourse.group/u/d42kn355)\ **Post date:** [May 25, 2020, 11:00pm UTC](https://lookmumnocomputer.discourse.group/t/troubleshooting-a-performance-filter/1015/5 "2020-05-25T23:00:01Z")
In regards the Jack Socket Wiring - See: > [@Help! Any jack wiring pics for amateur](https://lookmumnocomputer.discourse.group/t/help-any-jack-wiring-pics-for-amateur/802): > > Hi - i’m building all the Kosmo unit in lockdown but i have little electrical knowledge and can’t read the schematics confidently. currently finishing a couple of the 1145 VCLFO’S but the site jpegs aren’t very clear and i can’t see what wires go where. Can anyone take a pic of theirs for me? Free beers in return when you visit the Isle of Man! Cheers Phil The Filter can also self oscillate without anything hooked up to it, crank up the resonance and play around with the main knob and about can generate a nice sine wave (i believe) from it. ---
**Author:** ![fluxpavilion](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/fluxpavilion/32/2475_2.png) [@fluxpavilion](https://lookmumnocomputer.discourse.group/u/fluxpavilion)\ **Post date:** [May 26, 2020, 8:33am UTC](https://lookmumnocomputer.discourse.group/t/troubleshooting-a-performance-filter/1015/6 "2020-05-26T08:33:11Z")
awesome guys thanks i should have investigated more, the module works! my jack socket for input 1 was wired backwards, so no initial LED plus no signal from input 1 and i figured i had made a mistake somewhere, but a rewiring and it works there is an oddity though, my LPF is alot quieter than my HPF. I noticed a few people have commented that the HPF is quieter but i have it backwards over here ---
**Author:** ![klausklaerwerk](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/klausklaerwerk/32/4945_2.png) [@klausklaerwerk](https://lookmumnocomputer.discourse.group/u/klausklaerwerk)\ **Post date:** [May 26, 2020, 9:00am UTC](https://lookmumnocomputer.discourse.group/t/troubleshooting-a-performance-filter/1015/7 "2020-05-26T09:00:07Z")
the LPF is more quiet than HPF in mine. plus the HPF drops out when the frequency knob is above half way up. btw there are threads for all the modules here already and it’s likely your problems have been discussed over there, so no need to open a new thread for every issue that turns up. ---
**Author:** ![fluxpavilion](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/fluxpavilion/32/2475_2.png) [@fluxpavilion](https://lookmumnocomputer.discourse.group/u/fluxpavilion)\ **Post date:** [May 26, 2020, 9:08am UTC](https://lookmumnocomputer.discourse.group/t/troubleshooting-a-performance-filter/1015/8 "2020-05-26T09:08:42Z")
yeah i did just clock that and was jumping in here to ‘close’ this thread it feels easier to directly ask the exact questions im looking for answers, but i understand if the forum users dont like it done that way does get messy