# Module requests **URL:** \ **Category:** KOSMO MODULES\ **Created:** [January 19, 2020, 2:35pm UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39 "2020-01-19T14:35:13Z")\ **Posts on this page:** 20\ **Page:** 9
**Author:** ![WesleyV](https://avatars.discourse-cdn.com/v4/letter/w/bb73d2/32.png) [@WesleyV](https://lookmumnocomputer.discourse.group/u/WesleyV)\ **Post date:** [May 29, 2020, 9:07pm UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/161 "2020-05-29T21:07:19Z")
Was just scrolling around and I saw this post about the Midimuso - I I created a 3D printed Kosmo Format panel for it that seems to be working well for me so far. Here is a link if anyone is interested: > **[Midimuso Kosmo Format Modular Synth Panel by wvanderveen](https://www.thingiverse.com/thing:4366349)** > > This is a modular synthesizer panel for the Midimuso CV 12 kit:http://midimuso.co.uk/index.php/cv-12/ > I build my panels for 1/4" jacks, not the standard Eurorack size. These panels are meant for the 20CM Kosmo format (most notably popularized by Look... ---
**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:** [May 29, 2020, 10:44pm UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/162 "2020-05-29T22:44:37Z")
> [@Maxhirez](#): > > In that VLOG earlier this week where you went through the old bins there was one panel that you said was an attempt at an all-in-one unit. Have you ever thought about bringing something like that to project status? Either in the sense of using a 3372, or creating a full stand-alone LMNC mono (or poly) synth? yes max. after I have done the 3320 hi/low filter I’ll make a voice, I also have after that a plan for a poly module. to save me having to lug around a prophet that breaks all the time hahaha ---
**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:** [May 29, 2020, 10:48pm UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/163 "2020-05-29T22:48:08Z")
nice Wesley! one question I have regarding an un modified off the shelf midimuso with eurorack power. can you get enough power to the voltage reference? from my experience eurorack power usually doesnt whack out quite 12v. especially with 3 or more modules. and for the lm317 to do its thing the voltage input needs to be a bit over 1v above the desired reference. which meant for the module im doing around it I had to do a bit of modification to the circuit around the vref to make it work in less optimum power conditions. what’s your experience with it??? its more than fine when powered with a wall wart as your usually in nice and happy 12v zone, but most eurorack power doesn’t quite get there (I have tested all I have had to hand, fc powerdiy, doepfer monster case, befaco skiff, excalibus, tiptop etc ---
**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 29, 2020, 11:00pm UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/164 "2020-05-29T23:00:31Z")
Maybe I misunderstand what you’re saying but I have a TipTop µZeus powering 84HP of Eurorack and it reads 11.99V on my multimeter. ---
**Author:** ![WesleyV](https://avatars.discourse-cdn.com/v4/letter/w/bb73d2/32.png) [@WesleyV](https://lookmumnocomputer.discourse.group/u/WesleyV)\ **Post date:** [May 29, 2020, 11:09pm UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/165 "2020-05-29T23:09:49Z")
Hi Sam, Here is the Eurorack power I’m using: > **[Eurorack Power Supply - AI Synthesis](https://aisynthesis.com/product/eurorack-power-supply/)** > > An easy to build Eurorack Power Supply with convenient on-board connectors. The Build Guide is here. Each one I build has minute differences on the power rails, but mine are a smidge over 12v. That being said, my Midimuso actually wouldn’t track 1v per octave at first - I was having issues until I clipped out the LM317 and replaced it with a new one, and then things seemed to work fine. I worry though, since the midimuso apparently take 500 milliamps or something crazy - I’m worried I’m overtaxing my supply and I’m considering switching to a wall wart. One thing I noticed when trimming the voltage ref - I was able to expand the range of the voltage trimmer (and get close to 1v per octave) by decreasing the value of the 220r resistor connecting the Vout pin on the LM317 to pin 1 on the 5k trim pot. Be warned though, don’t go too low on that resistor or I’m pretty sure you will destroy the LM317. You could maybe take the 220r down to 100r or 75 in a pinch to squeeze yourself a bit closer to the desired voltage if you are getting like 10.5 instead of 10.6 on the test pad or something. Let me know how you fare! Another full disclosure, I am having some power issues which I described in this thread - hopefully they are not connected to the midimuso: > [@Too much in-rush current when starting up my modular?](https://lookmumnocomputer.discourse.group/t/too-much-in-rush-current-when-starting-up-my-modular/1068): > > Hi all, I’ve gotten some really great advice here so far, so I thought I’d seek further advice on some power issues with my modular. I have everything plugged into a single power strip, and when I flip the whole thing on, the 5v rails on my power supply work fine but the + - 12v rails aren’t giving off the voltage they need and the synth doesn’t properly power up (details of what kind of power supplies I’m using are below). I can mitigate this by plugging the wall warts in one at a time after f… best of luck, -Wes ---
**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 29, 2020, 11:09pm UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/166 "2020-05-29T23:09:58Z")
Wait, they’re using an LM317 to produce 10.6 V from 12 V? That’s a bit optimistic: ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/c/ca7ef96be29933ad9ce004de23d6113e5ae2c7d8.png) ---
**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:** [May 29, 2020, 11:17pm UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/167 "2020-05-29T23:17:05Z")
> [@WesleyV](#): > > Each one I build has minute differences on the power rails, but mine are a smidge over 12v. That being said, my Midimuso actually wouldn’t track 1v per octave at first - I was having issues until I clipped out the LM317 and replaced it with a new one, and then things seemed to work fine. I worry though, since the midimuso apparently take 500 milliamps or something crazy - I’m worried I’m overtaxing my supply and I’m considering switching to a wall wart. > > One thing I noticed when trimming the voltage ref - I was able to expand the range of the voltage trimmer (and get close to 1v per octave) by decreasing the value of the 220r resistor connecting the Vout pin on the LM317 to pin 1 on the 5k trim pot. Be warned though, don’t go too low on that resistor or I’m pretty sure you will destroy the LM317. You could maybe take the 220r down to 100r or 75 in a pinch to squeeze yourself a bit closer to the desired voltage if you are getting like 10.5 instead of 10.6 on the test pad or something. Let me know how you fare! > > Another full disclosure, I am having some power issues which I described in this thread - hopefully they are not connected to the midimuso: hi fredrik! after quite a bit of looking around ill find a link it seems quite fair game that a headroom of 1v is enough, I’ll try and find what I found regarding it, and it led me to do quite a bit of messing around because getting the problem I mentioned above from the lm317 I went on the hunt for an alternative, which lead me to sticking with an lm317 and figuring out if it can hack it. and so far its been more than fine, even the main one I have been using since November, and another prototype sitting in another module case thats used a lot. I also read in a forum of other peoples experiences saying 1v is the minimum headroom they have achieved, and I guess thats what rob from midimuso has been working off too. however in the midimuso setup anything even a tad lower than 12v is just impossible to get the reference voltage ---
**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:** [May 29, 2020, 11:18pm UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/168 "2020-05-29T23:18:11Z")
im still trying to understand why 3v was specified, as i saw numerous projects with less headroom. maybe it is when its working at its maximum ratings of consumption. which the midimuso is well under ---
**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:** [May 29, 2020, 11:20pm UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/169 "2020-05-29T23:20:34Z")
yes wes thats what I have gone for in the latest iteration. 100r and also (after reading on a robot forum that I mentioned to fredrik but I can’t remember what the heck it was) I isolated the trimpot from ground. its been faring good for about 2 months. ---
**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:** [May 29, 2020, 11:21pm UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/170 "2020-05-29T23:21:01Z")
but maybe you can unearth a better reason! ---
**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:** [May 29, 2020, 11:22pm UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/171 "2020-05-29T23:22:26Z")
![vreg](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/0/0ed8e13d20bdd75ad1de7ea16e7c222db6a79fbf.jpeg) thoughts??? this is it in its current form (haha current) the thing is 10.6 is nearly at the top of its headroom to the 10k is suffice to get to it. ---
**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:** [May 29, 2020, 11:28pm UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/172 "2020-05-29T23:28:01Z")
also if there is an alternative to getting a stable 10.6v comparable in cost and simplicity im all ears! it was suggested to try the LM117 but they are clunky bo bunky ---
**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 29, 2020, 11:36pm UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/173 "2020-05-29T23:36:01Z")
Yeah, it does say “up to” so low power use might be what’s saved you (and the midimuso folks) but if you’re designing for a dropout around 1-1.5 V you really want a low dropout regulator, which LM317 isn’t (it’s a mid-seventies design iirc). I’m still a bit surprised that you’re seeing only a volt, but guess I have to experiment a bit tomorrow 😃 There’s a ton of modern LDO options, but seems a reasonable replacement would be a LM1117-ADJ which is widely available, has max dropout of 1.25 V guaranteed at quite a bit of current, and should be available in the same package & pinout. EDIT: Increasingly convinced that the low dropout is because the LM317 doesn’t regulate, so it’s just the voltage drop over a saturated output transistor. To the breadboards! ---
**Author:** ![WesleyV](https://avatars.discourse-cdn.com/v4/letter/w/bb73d2/32.png) [@WesleyV](https://lookmumnocomputer.discourse.group/u/WesleyV)\ **Post date:** [May 29, 2020, 11:46pm UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/174 "2020-05-29T23:46:24Z")
While we are on the subject - Sam are you at all concerned about trying to run multiple of your tuner VCOs and a Midimuso off the same power supply? I seem to remember arduinos using a decent amount of current (and so does the midimuso), so I’m a little worried I’m gonna use all the current on my supply just off those modules alone. Would it be crazy/impractical to power the Arduinos separately? I have a different 5v source already in my case which I am considering using for the arduino part of the vco circuit. ---
**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 30, 2020, 12:20am UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/175 "2020-05-30T00:20:37Z")
> [@WesleyV](#): > > Be warned though, don’t go too low on that resistor or I’m pretty sure you will destroy the LM317. The resistor and the trimmer form a voltage divider (\*) that provides a voltage to the ADJ pin, and the regulator will tweak the output voltage to keep ADJ at 1.25 V. The pin itself only consumes 50-100 uA according to the datasheet, so the main load will be through the resistor & trimmer to ground. If you go too low, you may damage the trimmer, though – e.g. with 100 ohm the current is 1.25/100=12.5 mA which is a bit too much for a 10k trimmer (see [here](https://lookmumnocomputer.discourse.group/t/schematics-undestanding-and-drawing-them/1011/19)). \*) Well, in Sam’s sketch it’s not a divider. What was the idea behind not connecting the pot to ground? Seems to me that would turn it into a current regulator, not a voltage regulator, with the regulator trying to keep the current through resistor + trimmer high enough to drop 1.25 V, which doesn’t quite work since 1.25 V/50 uA = 25k. Are we sure it’s actually regulating when you’re seeing a 1 V drop, or could that be the Vce drop of the regulator’s power transistor? ---
**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 30, 2020, 12:30am UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/176 "2020-05-30T00:30:36Z")
> [@lookmumnocomputer](#): > > it was suggested to try the LM117 but they are clunky bo bunky You want the LM1117, not LM117 😃 Seems like LM117 is an LM317 in a [metal can](http://www.ti.com/lit/an/snoa033/snoa033.pdf)🤘 (TO-3 or TO-39), iiuc. That’s pretty metal, but not very practical (unless you need an extreme temperature range). EDIT: Older TI chips often use 1 for military grade, 2 for industrial, and 3 for commercial, with the main difference being temperature ranges. Seems TI no longer makes an LM217, but it’s available from others in case someone here prefers industrial over metal. ---
**Author:** ![antoine.pasde2](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/antoine.pasde2/32/326_2.png) [@antoine.pasde2](https://lookmumnocomputer.discourse.group/u/antoine.pasde2)\ **Post date:** [May 30, 2020, 2:37am UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/177 "2020-05-30T02:37:54Z")
The LM1084-ADJ is a pin compatible, low dropout, replacement for the LM317, its dropout is less than 1V at 1A at room temperature and above. ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/6/6d029393f8a1d11dcdc6f39fe91e9ff3818ecb08.png) And I’ll join my voice to Fredrik again and wonder why the trimpot in your schemaitc above is not connected to ground in the normal voltage regulator configuration. ![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/3/349b774227585d714467fb9a12ad6b865c2f0af6.png) ---
**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 30, 2020, 6:26am UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/178 "2020-05-30T06:26:56Z")
(The LM1084 would work, and is much beefier (5.5 A!) than the LM1117 mentioned earlier, but also more expensive ($0.88/1ku vs $0.33/1ku). The lower amp LM1086 is a slightly cheaper, but still not as cheap as the 1117.) ---
**Author:** ![antoine.pasde2](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/antoine.pasde2/32/326_2.png) [@antoine.pasde2](https://lookmumnocomputer.discourse.group/u/antoine.pasde2)\ **Post date:** [May 30, 2020, 7:51am UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/179 "2020-05-30T07:51:26Z")
> [@fredrik](#): > > is much beefier In current capability, but not in size as I’m assuming we’re looking at TO-220 packages for all of these regulators or voltage references. The LM1084 is indeed more expensive than the LM1117, (e.g. $2.60 vs $1.54 in single quantity at Digikey) but depending on the total current draw, its lower dropout voltage might give us just enough margin to be able to use Schottky diodes for power supply reversal protection which I prefer over the 10 ohm resistors/fuses (or the mostly harmless (to be polite) ferrite beads - although a MIDI to CV module with its microprocessor might be one of the rare modules where ferrite bead actually have a non-zero (but probably still negligible) effect). ---
**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:** [May 30, 2020, 8:52am UTC](https://lookmumnocomputer.discourse.group/t/module-requests/39/180 "2020-05-30T08:52:01Z")
I haven’t had a problem personally. powering a midimuso, 2 braids, 4 of the tuner VCOs and 5 or 6 more modules including a safety valve off 1 power supply. never had a problem, probably most definitely over its rating. but its been on for days at a time over a number of years. no melting or going into a wormhole yet! [Previous page](https://lookmumnocomputer.discourse.group/t/module-requests/39.md?page=8) [Next page](https://lookmumnocomputer.discourse.group/t/module-requests/39.md?page=10)