# Fart Box Builds **URL:** \ **Category:** KOSMO MODULES\ **Created:** [May 7, 2020, 9:02am UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828 "2020-05-07T09:02:18Z")\ **Posts on this page:** 20\ **Page:** 16
**Author:** ![ee.queue](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/ee.queue/32/24361_2.png) [@ee.queue](https://lookmumnocomputer.discourse.group/u/ee.queue)\ **Post date:** [October 27, 2023, 5:34pm UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/305 "2023-10-27T17:34:09Z")
Hi All, I was recently gifted a Fart Box PCB and I’m now in the process of ordering some components I don’t have on hand. I noticed that the BOM specifies ceramic capacitors for the non-polarized capacitors; I have some of the values on hand in ceramic, but I have a couple of the listed values in film capacitors (left over from building the Twin T). Is there any particular reason **not** to use film capacitors in this circuit? I remember, for example, that film capacitors were recommended in the Twin T build as ceramics created noise in the circuit. Any thoughts would be greatly appreciated 🙂 ---
**Author:** ![BenRufenacht](https://avatars.discourse-cdn.com/v4/letter/b/ba8739/32.png) [@BenRufenacht](https://lookmumnocomputer.discourse.group/u/BenRufenacht)\ **Post date:** [October 27, 2023, 7:57pm UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/306 "2023-10-27T19:57:48Z")
Using film capacitors should be just fine in that circuit. The BOM suggests ceramic just because they are the less costly option. ---
**Author:** ![ee.queue](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/ee.queue/32/24361_2.png) [@ee.queue](https://lookmumnocomputer.discourse.group/u/ee.queue)\ **Post date:** [October 28, 2023, 11:38pm UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/307 "2023-10-28T23:38:17Z")
Thanks! I’ll be sure to post the results here once it’s all ready to go. ---
**Author:** ![ee.queue](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/ee.queue/32/24361_2.png) [@ee.queue](https://lookmumnocomputer.discourse.group/u/ee.queue)\ **Post date:** [November 9, 2023, 11:56pm UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/308 "2023-11-09T23:56:56Z")
Okay, so. Following up on this; I don’t have an LED pushbutton, but I do have a momentary button and I have lots of LEDs. Would wiring an LED and a standard momentary pushbutton work? Looking at some of the other builds I’ve seem I’m thinking this would be the way to wire it up, but I’m not sure: ![PXL_20231109_234931400](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/e/7/e7df6824546149b3c12bdf9b7ae3ffe6a7d02d1c.jpeg) Any help with this would be greatly appreciated ---
**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:** [November 10, 2023, 2:25am UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/309 "2023-11-10T02:25:03Z")
yeah should work fine - 1&2 are LED and 3&4 are for the momentary button legs 🙂 ---
**Author:** ![ee.queue](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/ee.queue/32/24361_2.png) [@ee.queue](https://lookmumnocomputer.discourse.group/u/ee.queue)\ **Post date:** [November 10, 2023, 1:45pm UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/310 "2023-11-10T13:45:54Z")
Thanks! I noticed that for all the two pin molex connections they’re arranged with a round and a square pad. Looking at the PCB it seems like the round connections are going to ground, but - again - I’m not sure. Did I get that right too? ---
**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:** [November 11, 2023, 12:43am UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/311 "2023-11-11T00:43:53Z")
just #4 goes to ground ---
**Author:** ![Ben\_BJZ](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/ben_bjz/32/28608_2.png) [@Ben\_BJZ](https://lookmumnocomputer.discourse.group/u/Ben_BJZ)\ **Post date:** [March 10, 2024, 11:16pm UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/312 "2024-03-10T23:16:51Z")
Where can I find the fart box schematics? I built a fart box and it doesn’t work correctly and the schematics would make debugging easier. ---
**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:** [March 10, 2024, 11:22pm UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/313 "2024-03-10T23:22:11Z")
If you support LMNC on Patreon they’re there. ---
**Author:** ![Ben\_BJZ](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/ben_bjz/32/28608_2.png) [@Ben\_BJZ](https://lookmumnocomputer.discourse.group/u/Ben_BJZ)\ **Post date:** [March 10, 2024, 11:33pm UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/314 "2024-03-10T23:33:49Z")
I had downloaded the schematics from Patreon about a year ago (that is when I started building it) and they seem to be out of date. There is no front panel wiring and it is slightly different from the fart box 1.0 veroboard layout. ---
**Author:** ![lookmumnocomputer](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/lookmumnocomputer/32/23_2.png) [@lookmumnocomputer](https://lookmumnocomputer.discourse.group/u/lookmumnocomputer)\ **Post date:** [March 10, 2024, 11:37pm UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/315 "2024-03-10T23:37:53Z")
give it 20 mins itll be on the fart box page of the website. good to get it fixed. it is somewhere on this forum. i cant remember, i have put it on here a few times. but to save confusement. check the site in 20 mins ---
**Author:** ![Ben\_BJZ](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/ben_bjz/32/28608_2.png) [@Ben\_BJZ](https://lookmumnocomputer.discourse.group/u/Ben_BJZ)\ **Post date:** [March 10, 2024, 11:48pm UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/316 "2024-03-10T23:48:11Z")
I had downloaded this schematic from patreon about a year ago. I don’t know why it’s missing the pots. Thanks for the schematics. ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/1/d/1dbaf3560172921e27f414fafb7b8f908f2977db.png) ---
**Author:** ![MrEddy](https://avatars.discourse-cdn.com/v4/letter/m/b19c9b/32.png) [@MrEddy](https://lookmumnocomputer.discourse.group/u/MrEddy)\ **Post date:** [October 26, 2024, 12:14am UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/317 "2024-10-26T00:14:14Z")
Is the 5k (4.7k on the BOM) pot Linear or Log? I assume all linear B100k, and log A1meg, innit? ---
**Author:** ![SYNTHGUY57](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/synthguy57/32/14422_2.png) [@SYNTHGUY57](https://lookmumnocomputer.discourse.group/u/SYNTHGUY57)\ **Post date:** [October 26, 2024, 7:43am UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/318 "2024-10-26T07:43:49Z")
its linear , yes go for it ---
**Author:** ![krztoff](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/krztoff/32/29609_2.png) [@krztoff](https://lookmumnocomputer.discourse.group/u/krztoff)\ **Post date:** [January 16, 2025, 7:03pm UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/319 "2025-01-16T19:03:00Z")
How was this front panel made? It’s gorgeous ---
**Author:** ![nervous\_squirrel](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/nervous_squirrel/32/2871_2.png) [@nervous\_squirrel](https://lookmumnocomputer.discourse.group/u/nervous_squirrel)\ **Post date:** [January 16, 2025, 7:32pm UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/320 "2025-01-16T19:32:45Z")
Thanks very much! The panel is 1.5mm black anodised aluminium, with the lettering / graphical elements cut on a CNC router with tiny 0.4mm cutter. The cutter has a flat profile, i.e. isn’t a V-shaped engraving tool, and cuts a tiny amount into the surface. Just enough to take the black layer off - something like 0.05 or 0.10mm. The crucial bit is making sure the CNC bed is accurately flat - I usually take a skim off with a big 50mm cutter before getting started, to make sure the bed is level. The holes and perimeter are then cut with a 3mm cutter, and the edges folded on a folding machine. ---
**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:** [January 17, 2025, 1:24pm UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/321 "2025-01-17T13:24:25Z")
> [@nervous\_squirrel](#): > > One slightly strange issue though - the module doesn’t always power up when the synth is switched on, i.e. sometimes the oscillator LEDs don’t come on / no response from gate or trigger. It then comes back again after switching off and on again, and then works perfectly. I know you solved this but if you’re interested it’s [this issue](https://lookmumnocomputer.discourse.group/t/psu-startup-problems/4296) for which a solution is to [replace the rectifier diode from the positive regulator output to ground with a Schottky](https://lookmumnocomputer.discourse.group/t/psu-startup-problems/4296/17). (The rectifier on the negative side does not need to be replaced.) More detail: [https://www.youtube.com/watch?v=GQKkBUF3zvo](https://www.youtube.com/watch?v=GQKkBUF3zvo) ---
**Author:** ![nervous\_squirrel](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/nervous_squirrel/32/2871_2.png) [@nervous\_squirrel](https://lookmumnocomputer.discourse.group/u/nervous_squirrel)\ **Post date:** [January 18, 2025, 7:48pm UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/322 "2025-01-18T19:48:22Z")
Fantastic, thanks so much for taking the time to make that video. I’ll definitely change that diode if the problem appears again in future. Just watched your Geiger module video too - nice idea to include an output with envelopes, and thanks for mentioning the Nervous Squirrel module! ---
**Author:** ![krztoff](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/krztoff/32/29609_2.png) [@krztoff](https://lookmumnocomputer.discourse.group/u/krztoff)\ **Post date:** [January 31, 2025, 7:17am UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/323 "2025-01-31T07:17:35Z")
Anyone know which resistor on the PCB version of this is for the pushbutton LED? On the schematic it’s listed as R63, but I am not confident that matches up with the PCB or if that schematic pre-dates it. I cannot for the life of me get the LED in the pushbutton to brighten. It lights up, but is super dim no matter what size/color LED i put in. Jumpering the 1k R63 didn’t make a difference. ---
**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:** [January 31, 2025, 8:25am UTC](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828/324 "2025-01-31T08:25:02Z")
> [@Willi359](#): > > ![fb-annotated](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/3X/e/7/e7a2dfa1aef7f41425b438c9c81580992ac34e99.jpeg) I created this to help me dubug my second FartBox. Oszilator 1&2 got mixed up in the annotaion but otherwise it matches the shematic. R63, the one you are hunting did not get “assigned” to a functionality group, i missed it. maybe it helps. good luck [Previous page](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828.md?page=15) [Next page](https://lookmumnocomputer.discourse.group/t/fart-box-builds/828.md?page=17)