# Show me your mixers! **URL:** \ **Category:** KOSMO MODULES\ **Created:** [June 3, 2021, 1:17am UTC](https://lookmumnocomputer.discourse.group/t/show-me-your-mixers/3598 "2021-06-03T01:17:30Z")\ **Posts on this page:** 2\ **Page:** 2
**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:** [October 23, 2022, 10:11am UTC](https://lookmumnocomputer.discourse.group/t/show-me-your-mixers/3598/21 "2022-10-23T10:11:12Z")
Since I have a multi channel Bheringer mixer which I use to mix the modular output and some synths with I thought I would not have much to contribute to this thread, but maybe this could be of interest. In my modular I use ‘intermediate’ mixers (called Mix-O-Matic) which are signal and/or CV mixers. These are very simple in construction and easy to use. I’ve been using them for a while now and like multiples and attenuverters they are sort of a staple tool to me now. They consist of TL072s (but I could have used one TL074) which are configured as an inverting summing amplifier followed by an inverter each. This results in 2 summing circuits. For one I also output the inverse sum. ![20210218_233000](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/e/b/ebd0dc045358b71db1181b0f63e439439cd4eded.jpeg) Here is a look at two bread board implementations. ![20210219_161437](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/9/b/9bddf2ea287e5f49f069716f30e6a1142d7c9860.jpeg) ---
**Author:** ![jacobsteel](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/jacobsteel/32/30089_2.png) [@jacobsteel](https://lookmumnocomputer.discourse.group/u/jacobsteel)\ **Post date:** [November 29, 2024, 8:35am UTC](https://lookmumnocomputer.discourse.group/t/show-me-your-mixers/3598/22 "2024-11-29T08:35:09Z")
My battery operated stereo micro-mixer. 4 x stereo in (one mono in with gain/drive, goes into L+R on channel 1). Stereo AUX out - switchable aux-sends with a master pot. Stereo mixing with master pot. Either stereo output will drive headphones directly. I rebuilt a mixer I first made a couple of years back… I managed to shrink the insides by using finer gauge wiring, and got 9V battery operation + headphone direct drive by using 4 X LM386 (the 5th LM386 board is used for the mono-input, connecting to channel 1 via caps, so it won’t mono-bridge that stereo input). I ended up using pre built boards, and modified the gain (pins 1-8) to x20 to lower the noise floor. **Current version:** ![micro mixer schematic simple](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/a/6/a614f2d5527519f783b64664c41c39bd2da85109.jpeg) ![micro mixer outside](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/a/f/afd2c5636418d6541724e68640ddec59fd59ecc4.jpeg) ![micro mixer inside](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/9/7/97c80c953f249d54bedc94641015df6749f36fb0.jpeg) **First version:** Images below: The first version, using LM324 and dual rail. The first outlay with pots, switches, could be re-used… but the cables I had then were way too thick. And buffered inputs was overkill: ![micro mixer version 1 insides 2](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/6/2/62adbc14010129f4e677eeae335ca8ec3a081465.jpeg) ![micro mixer version 1 insides](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/3/9/392cdb65c76ec7b5994939ecebcad110e09f6507.jpeg) ![micro mixer version 1](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/6/3/63f8f7b9d2d833ecf2f6e1509628dfa86e11d62f.jpeg) The micro mixer now runs on 5 LM386 boards, on one 9V battery. Here’s a video: [![](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/3/4/34b6bce9029eab7fcd92b8376838164535149bb7.jpeg "Minimal Setup - First Test") ](https://www.youtube.com/watch?v=B-17rwSm6Xw) Yes, and I also added a 3.5 stereo input to my Behringer CA202 Finally I got a tiny fully battery operated setup. [https://www.instagram.com/p/DCzn1Tnujr3/?hl=en&img\_index=1](https://www.instagram.com/p/DCzn1Tnujr3/?hl=en&img_index=1) [Previous page](https://lookmumnocomputer.discourse.group/t/show-me-your-mixers/3598.md?page=1)