# 1163 Mini Mixer **URL:** \ **Category:** KOSMO MODULES\ **Created:** [September 28, 2020, 8:23pm UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890 "2020-09-28T20:23:40Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [September 28, 2020, 8:23pm UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/1 "2020-09-28T20:23:40Z")
Just noticed this has popped up > **[1163 MINI MIXER](https://store.lookmumnocomputer.com/collections/all/products/1163-mini-mixer)** > > This is the PCB and Panel to build the #1163 Mini Mixer, A module designed to mix 6 seperate inputs be it CV, Audio, Brainwaves whatever! into 1 output. Each channel has a level control and an on/off switch. The info on this project is over here :-... ---
**Author:** ![Willi359](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/willi359/32/19681_2.png) [@Willi359](https://lookmumnocomputer.discourse.group/u/Willi359)\ **Post date:** [February 10, 2022, 10:27am UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/2 "2022-02-10T10:27:23Z")
I built this mixer and got stuck: - sound get’s trough but is barely noticeable - the switches and potentiometers work - doubleckecked my (sloppy) soldering and swapped some parts (R1, R2, C5, C6, TL072cp) - this might be related to [mixer cutting freq](https://lookmumnocomputer.discourse.group/t/1163-mixer-cutting-frequency/3655) - i take to [power from my fartbox](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/24) - when i unplug power i hear something at normal volume while the capacitors inside are draining - the BOM sais “any” capacitor or resistor at multiple places maybe i went wrong there? ---
**Author:** ![Bpbby](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/bpbby/32/15259_2.png) [@Bpbby](https://lookmumnocomputer.discourse.group/u/Bpbby)\ **Post date:** [February 10, 2022, 10:59am UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/3 "2022-02-10T10:59:52Z")
Hey, is the fartbox still working when the mixer is plugged on the same power supply ? It could be that you do not get the +/12V supplied properly. I have this problem sometimes. Only the neg rail is being supplied. The sound you can hear could be just “passive” (no amplification). When you unplug, the power might send a short +12V to the opamp and give you a second of signal My view is that the capacitors are not absolutely needed to get this mixer to work. It is much better with it but it would work without it. If you can, check the opamp has got the +12-12V supplied on the correct pin (4 and 8) and you can also check continuity, this circuit is tiny so it shouldn’t take too long. Good luck ! ---
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [February 10, 2022, 10:17pm UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/4 "2022-02-10T22:17:31Z")
you cant go far wrong with it, have you checked the poer rails at the opamp? ---
**Author:** ![Willi359](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/willi359/32/19681_2.png) [@Willi359](https://lookmumnocomputer.discourse.group/u/Willi359)\ **Post date:** [February 11, 2022, 1:55pm UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/5 "2022-02-11T13:55:54Z")
I think the mixer is (mostly) fine. I killed the fbox i used as power supply. if you like drama you can [follow my progress in the fbox thread](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/279). to keep it short and on topic: i’ll report back when i have my basics sorted 😉 thx for your support and encouragement ---
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [February 11, 2022, 2:25pm UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/6 "2022-02-11T14:25:17Z")
Not too sure what you mean by using the FB as a power supply ---
**Author:** ![Sonosus](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/sonosus/32/13679_2.png) [@Sonosus](https://lookmumnocomputer.discourse.group/u/Sonosus)\ **Post date:** [February 11, 2022, 4:19pm UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/7 "2022-02-11T16:19:08Z")
Do you mean you’re taking the +/- 12V/ground connections from the fartbox? How is that being supplied? By “any resistor”, I think the BOM means the type of resistor (metal film, carbon film, wirewound, etc), not the value (measured in ohms - 500k, 100r, 2M, etc). Have you used the values from the ‘Designation’ column? Totally OT side note: would it work to have a seperate category for all the ‘official’ module topics? I often find myself having to search for them, and they aren’t all titled the same way which means it becomes quite cumbersome to find them after a while. ---
**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:** [February 11, 2022, 4:30pm UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/8 "2022-02-11T16:30:22Z")
Does this help? > [@List of LMNC modules and synth projects](https://lookmumnocomputer.discourse.group/t/list-of-lmnc-modules-and-synth-projects/3935): > > LMNC Kosmo Modules Module Store link Project link Discourse link 1007 MIDIMUSO MIDI-CV [store](https://store.lookmumnocomputer.com/collections/modules/products/1007-midimuso-midi-cv-module-pcb-panel-chipset)[project](https://www.lookmumnocomputer.com/1007-midi-cv)[discourse](https://lookmumnocomputer.discourse.group/t/1007-midimuso-midi-cv/1446) 1008 MIDI TO TRIGGER [store](https://store.lookmumnocomputer.com/collections/modules/products/1008)[project](https://www.lookmumnocomputer.com/projects#/1008miditotrig)[discourse](https://lookmumnocomputer.discourse.group/t/1008-midi-to-trigger/6199) 1113 PERFORMANCE FILTER [store](https://store.lookmumnocomputer.com/collections/modules/products/1113-kosmo-2-0-performance-filter)[project](https://www.lookmumnocomputer.com/performance-filter)[discourse](https://lookmumnocomputer.discourse.group/t/1113-performance-filter/14) 1114 FILTER GRR [store](https://store.lookmumnocomputer.com/collections/modules/products/1114-filter-grr)[project](https://www.lookmumnocomputer.com/1114-funky-filter)[discourse](https://lookmumnocomputer.discourse.group/t/1114-funky-clipping-filter-vca/2090) 1145 VCLFO [store](https://store.lookmumnocomputer.com/collections/modules/products/1145-kosmo-vclfo-lfo)[project](https://www.lookmumnocomputer.com/vclfo)[discourse](https://lookmumnocomputer.discourse.group/t/1145-vc-lfo-module/15) 1148 MODULATION STATION QUAD LFO [store](https://store.lookmumnocomputer.com/collections/modules/products/1148-modulation-station-quad-lfo-pcb-panel)[project](https://www.lookmumnocomputer.com/projects#/1148-quad-lfo)[discourse](https://lookmumnocomputer.discourse.group/t/1148-quad-vclfo/4065) 1153 BOUNCE BOUNCE BOUNCE BOUNCE BOUNCE BOUNCE BOUNCE [store](https://store.lookmumnocomputer.com/collections/modules/products/1153-bounce-bounce-bounce-bounce-bounce-bounce-bounce)[project](https://www.lookmumnocomputer.com/1153bounce)[discourse](https://lookmumnocomputer.discourse.group/t/1153-bounce-bounce-bounce-bounce-bounce-bounce-bounce-bounce/2499) 1157 MINI ADSR [store](https://store.lookmumnocomputer.com/collections/modules/products/1157-mini-adsr-chipset)[project](https://www.lookmumnocomputer.com/1157-mini-adsr)[discourse](https://lookmumnocomputer.discourse.group/t/1157-mini-adsr-module/359) 1158 VOLTAGE CONTROLLED… ---
**Author:** ![Sonosus](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/sonosus/32/13679_2.png) [@Sonosus](https://lookmumnocomputer.discourse.group/u/Sonosus)\ **Post date:** [February 11, 2022, 4:50pm UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/9 "2022-02-11T16:50:19Z")
I don’t know how I forgot about that. It only appears pinned when I log out, but that might just be my profile settings. Thanks! Bookmarked for future reference. ---
**Author:** ![Willi359](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/willi359/32/19681_2.png) [@Willi359](https://lookmumnocomputer.discourse.group/u/Willi359)\ **Post date:** [February 19, 2022, 3:22pm UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/10 "2022-02-19T15:22:43Z")
> [@Bpbby](#): > > If you can, check the opamp has got the +12-12V supplied on the correct pin (4 and 8) and you can also check continuity, this circuit is tiny so it shouldn’t take too long. > Good luck ! - @Bpbby was right. pin 8 was missing it’s 12v - circumvented any power proplems i might have had by adding a “paid & prebuilt” power supply - [now it’s working](http://wilke.zone/LMNK/mixer_working.mp4) (demo clip) ---
**Author:** ![richy486](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/richy486/32/23222_2.png) [@richy486](https://lookmumnocomputer.discourse.group/u/richy486)\ **Post date:** [June 22, 2022, 7:41pm UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/11 "2022-06-22T19:41:50Z")
Having similar problems, no sound coming out. Pin 8 seems to be connected to ground, c3 and +12v don’t seem to be connected to pin 8 or ground. Not sure how this is happening - using b100k pots - using on/off switches with no third pin - is the power connector at the bottom? input 1 is at the top on the front panel but input 1 is at the bottom near the output on the back. I plugged 1 into 6, 2 into 5 etc. and output into output - checked plugging in input one and adjusting input 6 ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/0/0/009f1048fbe93cb5e167a882d2b559d0319b668c.jpeg) ---
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [June 22, 2022, 9:07pm UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/12 "2022-06-22T21:07:34Z")
is the TLO72 and power header oriented correctly. There’s nothing else that can really go wrong, but if your not getting the correct voltages at the OP AMP nothing is going to work, ---
**Author:** ![richy486](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/richy486/32/23222_2.png) [@richy486](https://lookmumnocomputer.discourse.group/u/richy486)\ **Post date:** [June 22, 2022, 9:11pm UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/13 "2022-06-22T21:11:19Z")
Yup the notch’s is pointing away from the power socket. I removed the chip and header to see if pin 8 still connects to ground and it does Looking closely, surely I’m seeing this wrong but pin 8 shouldn’t connect to pin 3 over the large area right? (pin 3 should connect to ground though, which it does) ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/2/4/240ce551c09fe4cf67f7f31d6f3f77e5bf3a7306.jpeg) ---
**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:** [June 22, 2022, 9:36pm UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/14 "2022-06-22T21:36:24Z")
You appear to have drawn a line between pins 3 and 5, not 3 and 8. ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/2/3/23ddece2e8fe5c3df9765e66975964df596fd90f.png) ---
**Author:** ![richy486](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/richy486/32/23222_2.png) [@richy486](https://lookmumnocomputer.discourse.group/u/richy486)\ **Post date:** [June 22, 2022, 9:56pm UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/15 "2022-06-22T21:56:29Z")
OMG thanks so much, i knew i must have been thinking about it wrong somehow but i couldn’t see it ---
**Author:** ![richy486](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/richy486/32/23222_2.png) [@richy486](https://lookmumnocomputer.discourse.group/u/richy486)\ **Post date:** [June 23, 2022, 11:58am UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/16 "2022-06-23T11:58:32Z")
Just want to confirm two things 1. is it ok to use two pin switches leaving the third pin on the board empty? 2. having input 1 on the face plate connect to 6, 2 to 5 etc.? ---
**Author:** ![eric](https://avatars.discourse-cdn.com/v4/letter/e/898d66/32.png) [@eric](https://lookmumnocomputer.discourse.group/u/eric)\ **Post date:** [June 23, 2022, 12:17pm UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/17 "2022-06-23T12:17:36Z")
It is OK… _IF_ you have put them in in the right orientation… Unfortunately I don’t own that module so I can’t confirm if your orientation is the correct one. Try shorting with a wire the middle pin and the non-connected pad of one switch and see if it works… ---
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [June 23, 2022, 1:47pm UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/18 "2022-06-23T13:47:15Z")
Two pin switches are fine and your orientation is correct. The inputs are all identical except in name, so having the legends reversed between PCB/FP has no effect. Are you getting +12 and -12V on the correct pins on the OP-AMP. ---
**Author:** ![Mechamilk](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/mechamilk/32/150_2.png) [@Mechamilk](https://lookmumnocomputer.discourse.group/u/Mechamilk)\ **Post date:** [September 25, 2022, 10:43am UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/19 "2022-09-25T10:43:45Z")
Hello, I was breadboarding this module from the schematic and I have an issue. Every time i add an input volume it adds to the output voltage and so it outputs 5v with a single input, 10v with 2 inputs … What i’m doing wrong? ---
**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:** [September 25, 2022, 11:35am UTC](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890/20 "2022-09-25T11:35:00Z")
Sounds like nothing wrong, if I understand your question. A mixer adds its inputs. Of course you can’t get much more than 10 V out of the op amp, so with a third input, if all of them are 5 V, the output will be clipped. Assuming you don’t want clipping, you then have to back down on the three (or four, five, or six) attenuator pots. I like [mixers that have a variable resistor](https://lookmumnocomputer.discourse.group/t/ao-dc-mixer-module/3373) in the first stage feedback for that reason, you can just decrease the gain on that stage instead of having to fiddle with all the input pots. [Next page](https://lookmumnocomputer.discourse.group/t/1163-mini-mixer/1890.md?page=2)